Advancing the Understanding of Mexico's Geology And ...

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Advancing the Understanding of Mexico's Geology And Hydrocarbon Potential

PRESENTATION ABSTRACTS DAY 1 – NOVEMBER 19, 2020

SESSION I: TECTONICS AND STRUCTURAL GEOLOGY

1.I Key highlights of Mexico’s Mesozoic-Cenozoic Plate Tectonic Evolution James Pindell (presenter), Tectonic Analysis, Rice University; R. Molina-Garza, Centro de Geociencias, Universidad Nacional Autónoma de México; R. Graham, Imperial College London; D. Villagómez, Tectonic Analysis; B. Weber, Ensenada Center for Scientific Research and Higher Education (CICESE) ...................................................................................................................... 4

1.II Relating Structural Style of Campeche Salt Basin, Southwestern Gulf of Mexico to Subtle, Northward Dip Variations in its Underlying Basement Md Nahidul Hasan (presenter), P. Mann, University of Houston .................................................. 7

1.III Integrated Cretaceous Plate Tectonics and Structural Geology in Southern Mexico Rod Graham (presenter), Imperial College London; J. Pindell, D. Villagomez, Tectonic Analysis; R. Molina-Garza, M. Sierra Rochas, Universidad Nacional Autónoma de México; J. Granath, Granath and Associates ............................................................................................................................ 8

1.IV Comments on the Regional Structure of the Salina del Istmo Basin, Southern Gulf of Mexico Daniel Olivares Ramos, Petroleum Geology Consultant ............................................................... 8

1.V Balanced Structural Geological Model of the Zaap Field Marlen Medina Macedo, Facultad de Ingeniería, Universidad Nacional Autónoma de México – Spanish Presentation .................................................................................................................. 9

1.VI Paleomagnetism of the Barremian Chivillas Formation, NW Cuicateco Terrane: Evidence for a final Stage Opening of the Gulf of Mexico? Bernardo Ignacio García Amador (presenter), B. Ortega-Guerrero, L. Alva-Valdivia, Instituto de Geofísica, Universidad Nacional Autónoma de México .............................................................. 25

SESSION II: SEDIMENTOLOGY, STRATIGRAPHY AND BIOSTRATIGRAPHY

2.I The Importance of Regional to Basin-scale Paleogeographic Reconstructions for Exploration in Offshore Mexican Basins John W. Snedden, Institute for Geophysics, The University of Texas at Austin ........................... 26

2.II New Perspectives on the Todos Santos “Group”, the Chontal an Allochthon, and the Rotation History of the Chiapas Massif, Southern Mexico Roberto Molina Garza (presenter), Centro de Geociencias, Universidad Nacional Autónoma de México; J. Pindell, Tectonic Analysis .......................................................................................... 26

2.III Paleo-Canyons and Hydrocarbon Trapping in the Tampico-Misantla Basin, Eastern Mexico Stephen P. J. Cossey, Cossey and Associates Inc. (presenter); Mark R. Bitter, Marbit Geoconsulting ........................................................................................................................... 30

2.IV Near Shore Untapped Hydrocarbon Potential from Burgos to Southeast Offshore Mexico Karyna Rodriguez (presenter), N. Hodgson, Searcher ................................................................ 31

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2.V Sedimentologic Characterization of Sandstones in Chicontepec Basin José Aurelio España Pinto (presenter), D.M. Anaya-Saldívar, J.A. España-Pinto, R. Nicolás-López, O.C. Valdiviezo-Mijangos y J.M. Espinosa-Ortega, Instituto Mexicano del Petróleo.................... 31

2.VI Bioevents and Microfacies from the Upper Jurassic Tithonian (Pimienta Formation) in the Northeast of Mexico: Biostratigraphic, Paleonvironmental and Economic Implications Baltazar Hernández Sánchez, Petróleos Mexicanos (PEMEX) – Spanish Presentation ................. 32

2.VI Influence of Depositional Sedimentary Record on Diagenesis and Reservoir Quality: Assessment of Preserved Aeolian Norphlet Sandstone (Upper Jurassic) Mexico: Current Understanding and Future Prospects Afsoon Kazerouni, Bemidji State University ............................................................................... 37

DAY 2 – NOVEMBER 20, 2020

SESSION III: GEOCHEMISTRY AND BASIN MODELING

3.I The ‘Missing Source Rocks’ of the Gulf of Mexico Mega-Basin Andrew Pepper (presenter), Andrew Pepper, L. Heister, A. Pradono, M. Moldowan, This is Petroleum Systems LLC ............................................................................................................. 38

3.II Oil and Gas Resources of the Tampico - Misantla Basin Alfredo E. Guzmán, Mexican Petroleum Company .................................................................... 42

3.III New Exploration Play Concepts in the Tampico-Misantla Basin, from an Understanding of its Thermal Burial History and Source Rock Maturation Mark Shann (presenter), K. Vazquez Reyes, M.B. Canchola, Geomarcas SRL and Wintershall DEA42

3.IV Environmental Drivers of Organic Matter Deposition into the Pimienta Formation During the Jurassic–Cretaceous Transition in Central-Eastern Mexico Mario Martínez-Yáñez (presenter), SEPI-ESIA Unidad Ticoman, Instituto Politécnico Nacional; F. Núñez-Useche, Instituto de Geología, Universidad Nacional Autónoma de México ................... 42

3.V The Southern Gulf of Mexico: A Natural Laboratory of Petroleum Formation Demetrio Santamaría-Orozco, Univerisdad Nacional Autónoma de México – Spanish Presentation ............................................................................................................................. 43

SESSION IV: GEOPHYSICS AND RESERVOIR CHARACTERIZATION

4.I From Data to Discovery in the Gulf of Mexico South: New Methods for Digital and Subsurface Integration Marco Antonio Arreguin, Western Geco Mexico, Central America and the Caribbean ............... 46

4.II Results of the Application of Rock Physics in Unconventional Resources Hugo Avalos Torres (presenter), L. Velasquez-Contreras, M.A. Porras Vazquez, O. Fabela-Rodriguez, Petróleos Mexicanos (PEMEX) – Spanish Presentation ............................................. 46

4.III Lithology’s Petroelastic Characterization of the Eagle Ford Group by Using Modern Rock Physics Templates Rubén Nicolás-López (presenter), J. M. Espinosa-Ortega, J.A. España-Pinto, O.C. Valdiviezo-Mijangos, Instituto Mexicano del Petróleo ................................................................................ 49

4.IV Qualitative Interpretation of Potential Methods in the Terrestrial Portion of the Geological Province of the Yucatan Platform: the Extension to Mexico of the Sedimentary Basins of Corozal (Belize) and Petén (Guatemala) Edilberto R. Hernández Flores, Independent Consultant– Spanish Presentation ........................ 50

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4.V Methodology for Regional Velocity Models Using 2D and 3D Data for Depth Conversion Moises Huicochea Campos, Schlumberger (presenter); F. Rocha Legorreta, Instituto Mexicano del Petróleo; D. M. Tellez Castro, Universidad Central de Venezuela, S. R. Mata Garcia, Schlumberger ........................................................................................................................... 53

4.VI AVO Analysis and Characterization of Shallow Geo-Risks: a Case Study in Deep-Water Gulf of Mexico David López Palacios (presentador); J.M. Espinosa Ortega, Instituto Mexicano del Petróleo ..... 66

SPECIAL PRESENTATIONS

SP.I Instituto Mexicano del Petróleo: Solutions for the Petroleum Industry Marco Antonio Osorio Bonilla, Director, Instituto Mexicano del Petróleo (IMP) ................................... 73

SP.II The Role of Geology in Exploration and Production: Opportunities for Technology Transfer in Mexico Ulises Neri Flores, General Director for the Promotion of Productive Chains and Investment in the Energy Sector, Economy Secretariat, Government of Mexico .............................................. 73

SP.III Integration of Seismic Methods and Potential Methods for Geophysical Image Building Humberto Salazar Soto (presenter), Leonardo Enrique Aguilera Gómez, Alfredo Vazquez Cantú, Pemex Exploración y Producción ............................................................................................... 73

BIOGRAPHICAL SKETCHES

WELCOME AND OPENING REMARKS ......................................................................................... 74

SESSION I: TECTONICS AND STRUCTURAL GEOLOGY .................................................................. 74

SESSION II: SEDIMENTOLOGY, STRATIGRAPHY AND BIOSTRATIGRAPHY .................................... 76

SESSION III: GEOCHEMISTRY AND BASIN MODELING ................................................................. 78

SESSION IV: GEOPHYSICS AND RESERVOIR CHARACTERIZATION ................................................ 80

SPECIAL PRESENTATIONS .......................................................................................................... 82

CLOSING PANEL DISCUSSION .................................................................................................... 83

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PRESENTATION ABSTRACTS


SESSION I: TECTONICS AND STRUCTURAL GEOLOGY 1.I Key highlights of Mexico’s Mesozoic-Cenozoic Plate Tectonic Evolution James Pindell (presenter), Tectonic Analysis, Rice University; R. Molina-Garza, Centro de Geociencias, Universidad Nacional Autónoma de México; R. Graham, Imperial College London; D. Villagómez, Tectonic Analysis; B. Weber, Ensenada Center for Scientific Research and Higher Education (CICESE) Pangea formed by E to W diachronous collision of Laurentia and Gondwana. We propose that the resulting orogenic crustal thickness was likely great in northern Mexico, producing Permo-Triassic anatectic granites (Coombs et al. 2020) that were exhumed from mid-crustal levels and dispersed southwards to Veracruz, forming the continental “Peninsular Mexico”, by extreme Triassic–mid Jurassic sinistrally-oblique extension (Pindell et al. 2020a). We also propose that the Cuicateco basement was part of a NW-SE trending “North Oaxaca Transfer” along which the Oaxaca Block migrated sinistrally and transtensionally to the SE in the Jurassic-Early Cretaceous (Pindell et al. 2020a). By the earliest Cretaceous, we argue the “Chivillas Basin” had formed by sinistral transtension between the Cuicateco and Oaxaca basements, forming a marine channel connected to the Proto-Caribbean Seaway to the SE (Graham et al. 2020). Combined, these two mechanisms allowed the emplacement of the pre-Mesozoic continental crust of Peninsular Mexico and Oaxaca into the Colombian Overlap Position, without invoking the concept of a discrete Mojave-Sonora Megashear in the north for which field evidence remains scant (Pindell et al. 2020a). In the Gulf of Mexico (GoM), NW-SE rifting between Yucatan and the northern GoM generated a depression (synrift phase) that was probably marine in the Sinemurian and certainly again in the Bajocian when GoM salt was deposited (Pindell et al. 2020a). Strontium isotope ages indicate that salt deposition certainly began and may also have culminated at 169 Ma (Posey 1986; Pulham et al. 2019; Pindell et al. 2019; 2020b; Snedden and Galloway 2019; Amezcua et al. 2020). Subsequent rotational seafloor spreading (drift phase, which likely began in the Bathonian and ended in the Berriasian) produced the oceanic crustal window that we can map today with seismic reflection and refraction, aeromagnetic and satellite gravity data (Pindell et al. 2016; 2020b; Sandwell et al. 2014). The East Mexico Transform along the western GoM is well defined by deep penetration seismic data that can image Mexico’s continental Moho (Pindell et al. 2020a), passing to the south between the Mixtequita and Cuicateco complexes (Petapa Fault of Molina-Garza et al. 2020a). Mixtequita, Chiapas Massif, and Yucatan all rotated together during the drift stage but not during the synrift stage (Pindell et al. 2020a; Molina-Garza and Pindell, this volume). Passive margin subsidence and sedimentation ensued across areas of continental crust in the Cretaceous, but subduction and arc development remained active in the western offshore along poorly understood plate boundary scenarios. It is generally accepted that the Arperos backarc basin closed along the western flank of Peninsular Mexico and Oaxaca by the Aptian-Albian (Martini et al. 2010), and that continued shortening within Mexico produced the Late Cretaceous–Paleogene intracratonic Sierra Madre Oriental thrustbelt, presumably under conditions of flat-slab, east-dipping subduction (Gray et al. 2020). To the SE, in Maastrichtian-Paleogene time, the southern North American passive margin of eastern Chortis Block (restored to Oaxaca), Tehuantepec, Guatemala and Belize collided with the arc and oceanic elements of the leading edge of the Caribbean Plate, which are now displaced to the east and found in the Nicaragua Rise,

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Jamaica and central Cuba (Pindell and Kennan 2009). Several assemblages of rock were accreted to southern North America in this event, including the Siuna Complex (Nicaragua, Escuder-Viruete et al. 2019), the Chontal Complex (Tehuantpec, Molina-Garza et al. 2020b), and the El Tambór, Chuacús, and Santa Cruz complexes (Guatemala, Ratschbacher et al. 2009), along with the synorogenic sediments that attend them (e.g., parts of the Chontal, the Ocozocoaltla, the Soyaló, and the Sepur units of SE Oaxaca, Chiapas and Guatemala). During and after the arc collision, and certainly by the Paleocene, the flat-slab subduction in the west likely triggered the separation of Chortis from Oaxaca (Pindell and Kennan 2009). Chortis, which now was an obducted body upon the flat-slab Caribbean lithosphere, and the colliding arc elements to the east of it effectively remained with the Caribbean Plate, while the continental crust of southern Mexico (Oaxaca, the Yucatan Block and the Bahamas) migrated to the WSW over the local mantle (Pindell and Kennan 2009). This established the paleo-Motagua shear zone from SW Mexico to Belize, and led to the middle Eocene collision of Central and Eastern Cuba and Hispaniola with the Bahamas Platform. Since the middle Eocene, the 1200 km-long Cayman Trough has opened, thus isolating Central and Eastern Cuba and the Yucatán Basin as part of the North American Plate, and accommodating the majority of the relative motion along the plate boundary between southern Mexico (Oaxaca-Yucatan) and the Caribbean (Jamaica, Nicaragua Rise, and the Chortis Block). The rotational progress of Chortis (Molina-Garza et al. 2019) along southern Mexico can be mapped by noting the eastward migration of the onset of subduction related magmatism along the southern Mexican coast, the position of which (near the coast) indicates a return to normal-dipping subduction after the Laramide phase (late Eocene-Oligocene). An important Neogene phase of evolution has affected southern Mexico, as well. Although it was once considered that the passage of the Chortis Block drove the Chiapanecan orogeny since the beginning of the middle Miocene, it is easily shown that Chortis was too far east by 18 Ma to have caused the Chiapanecan deformation (Pindell et al. 2009; Molina-Garza et al. 2019. Instead, it was the onset of subduction beneath Mexico in the wake of Chortis, hence always migrating east and doubling the lithospheric layering as it became established, that has caused the shortening (Pindell and Kennan 2009; Pindell and Miranda 2011; Villagomez and Pindell 2020a). Also in the Neogene, was the flattening of the subducting Cocos Plate, the geometry of which has produced strong Neogene uplift in Cuicateco and which is now expanding into Chiapas where it has caused thick-skinned thrusting and uplift of the Chiapas Massif behind the Sierra de Chiapas foldbelt (Graham et al. 2020; this volume; Pindell et al. 2020c; Villagomez and Pindell 2020b), during which the massif has rotated about 20° clockwise (Molina-Garza et al. 2020c; Pindell and Molina-Garza, this volume). Restoration of the shortening and the rotation allows a crude alignment of the Tonalá Fault with the Chacalapa and Motagua fault zones in Oaxaca and Guatemala, respectively, all of which are highly mylonitic and, we suggest, collectively comprised the North America–Caribbean plate boundary prior to the middle Miocene (Graham et al. 2020). Since then, the Chiapanecan orogeny has disrupted and displaced the plate boundary, especially along the Chipehua Fault in the western Gulf of Tehuantepec. It might be hypothesised that a new E-W plate boundary segment may form/be forming across the Tehuantepec Shelf between the Motagua Fault and the Middle America Trench south of Oaxaca, which will cause the accretion of the Tehuantepec Shelf to North America. References Amezcua, N., Rochin, H. and Martínez, L.E. 2020. Preliminary strontium isotope stratigraphy of the Jurassic Minas Viejas Formation, Mexico: Geology and hydrocarbon potential of the circum-Gulf of Mexico pre-salt section. AAPG Datapages/Search and Discovery Article #90369, AAPG Hedberg Conference, February 4–6, 2020, Mexico City, Mexico, http://www.searchanddis covery.com/abstracts/html/2020/hedberg-90369/ abstracts/2020.HB.Mexico.29.html

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Coombs, H., Kerr, A., Pindell, J., Buchs, D., Weber, B. and Solari, L. 2020. Petrogenesis of the crystalline basement along the western Gulf of Mexico: Post-collisional magmatism during the formation of Pangea. Geological Society of America Special Papers, 546, https://doi.org/10.1130/2020.2546(02) Escuder-Viruete, J., Andjic, G., Baumgartner-Mora, C., Baumgartner, P.O., Castillo-Carrión, M., and Gabites, J., 2019, Origin and geodynamic significance of the Siuna Serpentinite Mélange, Northeast Nicaragua: Insights from the large-scale structure, petrology and geochemistry of the ultramafic blocks, Lithos, 340–341, 1–19. Graham, R., Pindell, J., Molina-Garza, R., Granath, J. and Villagómez, D. 2020. Structural sections through the Cuicateco-Veracruz and Chiapas. The Geological Society of London, Special Publications, 504. Gray, G.G., Villagomez, D. et al. 2020. Late Mesozoic and Cenozoic thermotectonic history of eastern, central and southern Mexico as determined through integrated thermochronology, with implications for sediment delivery to the Gulf of Mexico. The Geological Society of London, Special Publications, 504, https://doi.org/10.1144/SP504-2019-243 Martini, M., Ferrari, L., López-Martínez, M. and Valencia, V. 2010. Stratigraphic redefinition of the Zihuatanejo area, southwestern Mexico. Revista Mexicana de Ciencias Geológicas, 27, 412–430, http://ref.scielo.org/qnyt5r Molina-Garza, R., van Hinsbergen, D.J.J., Boschman, L.M., Rogers, R.D., Ganerød, M., 2019. Large-scale rotations of the Chortís Block (Honduras) at the southern termination of the Laramide flat slab. Tectonophysics 760, 36–57. doi:10.1016/j.tecto.2017.11.026. Molina Garza, R.S., Lawton, T.F., Barboza Gudiño, J.R., Sierra-Rojas, M.I., Guadarrama, A., and Pindell, J., 2020a, Geochronology and correlation of the Todos Santos Group, western Veracruz and eastern Oaxaca States, Mexico: Implications for regional stratigraphic relations and the rift history of the Gulf of Mexico, in Martens, U., and Molina Garza, R.S., eds., Southern and Central Mexico: Basement Framework, Tectonic Evolution, and Provenance of Mesozoic–Cenozoic Basins: Geological Society of America Special Paper 546, https://doi.org/10.1130/2020.2546(06). Molina Garza, R.S., Pindell, J., Coombs, H., Weber, B., and Peña Alonso, T., 2020, Definition of tectonic elements in Tehuantepec, southeast Mexico: An integrated geophysical, geochronological, and stratigraphic perspective, in Martens, U.C., and Molina Garza, R.S., eds., Southern and Central Mexico: Basement Framework, Tectonic Evolution, and Provenance of Mesozoic–Cenozoic Basins: Geological Society of America Special Paper 546, p. 1–26, https://doi. org/10.1130/2020.2546(15). Molina-Garza, R., Pindell, J., and Catalina Montaño Cortés, P., 2020, Slab flattening and tractional coupling drove Neogene clockwise rotation of Chiapas Massif, Mexico: Paleomagnetism of the Eocene El Bosque Formation Journal of South American Earth Sciences 104, doi.org/10.1016/j.jsames.2020.102932 Pindell, J.L., and Kennan, L., 2009, Tectonic evolution of the Gulf of Mexico, Caribbean and northern South America in the mantle reference frame: An update, in James, K.H., Lorente, M.A., and Pindell, J.L., eds., The Origin and Evolution of the Caribbean Plate: Geological Society, London, Special Publication 328, p. 1–55, https://doi.org/10.1144/SP328.1. Pindell, J., Miranda, E., 2011. Linked kinematic histories of the Macuspana, Akal-Reforma, Comalcalco, and deepwater Campeche basin tectonic elements, southern Gulf of Mexico: Gulf Coast Association of Geological Societies Transactions, 61, 353–361. Pindell, J., Miranda, C.E., Cerón, A. and Hernandez, L., 2016, Aeromagnetic map constrains Jurassic–Early Cretaceous synrift, break up, and rotational seafloor spreading history in the Gulf of Mexico, In: Lowery, C., Snedden, J. et al. (eds.) Mesozoic of the GoM. GCSSEPM Perkins–Rosen Research Conference, Transactions, Houston, TX. Pindell, J., Villagomez, D., Horn, B.W. and Garza, R.M. 2019. Middle Jurassic tectonic models for the GoM in light of new Bajocian ages for proximal salt deposition. Salt Tectonics, Associated Processes, and Exploration Potential: Revisited 1989–2019. GCSSEPM Annual Perkins–Rosen Research Conference, 67–88. Pindell, J., Villagómez, D., Molina-Garza, R., Graham, R. and Weber, B. 2020a. A revised synthesis of the rift and drift history of the Gulf of Mexico and surrounding regions in the light of improved age dating of the Middle Jurassic salt. The Geological Society of London, Special Publications, 504, https://doi.org/10.1144/SP504-2020-43 Pindell, J., Weber, B. et al. 2020b. Strontium Isotope Dating of Evaporites and the Breakup of the GoM and Proto-Caribbean Seaway. Geological Society of America, Special Papers, 546, https://doi.org/10.1130/2020.2546(12)

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Pindell, J., Molina-Garza, R., Villagómez, D., Martens, U., Graham, R., Stockli, D., Weber, B. and Sierra-Rojas, M.I., 2020c, Provenance of the Miocene Nanchital conglomerate, western Chiapas Foldbelt, Mexico: implications for reservoir sands in the Sureste Basin, Greater Campeche Province, in Davison, I., Hull, J., and Pindell, J. (eds.), The Basins, Orogens and Evolution of the Southern Gulf of Mexico and Northern Caribbean, Geol Soc. London SP 504. Posey, H.H., 1986, Regional Characteristics of Strontium, Carbon and Oxygen Isotopes in Salt Dome Cap Rocks of the Western Gulf Coast [Ph.D. diss.]: Chapel Hill, North Carolina, University of North Carolina at Chapel Hill, 264 p. Pulham, A., Salel, J.-F. et al. 2019. The Age of Louann Salt: insights form historic isotopic analysis in salt stocks from the Onshore Interior Salt Basins of the Northern GoM. 35th Annual GCSSEPM Foundation Perkins-Rosen Research Conference, 8–9 December 2016, Houston, TX. Salt Tectonics, Associated Processes, and Exploration Potential: Revisited 1989–2019, Abstract only, 64–66. Ratschbacher, L., Franz, L., Min, M., Bachmann, R., Martens, U., Stanek, K., Stübner, K., Nelson, B.K., Herrmann, U., Weber, B., L´opez-Martínez, M., Jonckheere, R., Sperner, B., Tichomirowa, M., Mcwilliams, M.O., Gordon, M., Meschede, M., Bock, P., 2009. the North American-Caribbean plate boundary in Mexico-Guatemala- Honduras. Geol. Soc. London Spec. Pub. 328, 219–293. Sandwell, D.T., Muller, R.D., Smith, W.H.F., Garcia, E. and Francis, R. 2014. New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure. Science, 346, 65–67, https://doi.org/10.1126/science.1258213 Snedden, J.W. and Galloway, W.E. 2019. The GoM Sedimentary Basin: Depositional Evolution and Petroleum Applications. Cambridge University Press, 326pp. Villagomez, D., and Pindell, J., 2020a, Thermochronology of the southern Mexican Margin (Xolapa Belt), Acapulco to Puerto Angel: crustal dynamics of a trench–trench–transform triple junction, in Martens, U., and Molina Garza, R.S., eds., Southern and Central Mexico: Basement Framework, Tectonic Evolution, and Provenance of Mesozoic–Cenozoic Basins: Geological Society of America Special Paper 546, https://doi.org/10.1130/2020.2546(14). Villagómez, D., and J. Pindell, 2020b, Cooling and uplift history of the Chiapas Massif and its influence on sedimentation and deformation in the adjacent Sierra de Chiapas Basin, in Martens, U., and Molina Garza, R.S., eds., Southern and Central Mexico: Basement Framework, Tectonic Evolution, and Provenance of Mesozoic–Cenozoic Basins: Geological Society of America Special Paper 546, DOI: 10.1130/2020.2546(17)

1.II Relating Structural Style of Campeche Salt Basin, Southwestern Gulf of Mexico to Subtle, Northward Dip Variations in its Underlying Basement Md Nahidul Hasan (presenter), P. Mann, University of Houston The late Jurassic Campeche salt basin in the southern GOM forms a passive margin foldbelt with an updip zone of normal faults in the 10-km-thick, 80-km wide late Miocene to Recent Comalcalco and associated rifts and a coeval, 500-km-wide, downdip zone of deeper-water, salt-cored folds, thrusts, and diapirs. In order to reconstruct the geometry and dip variations of the top of basement along which the passive margin foldbelt evolved, we have integrated magnetic data to constrain the top basement surface with 23,600 line-km of pre-stack depth migrated 2D seismic data to constrain the overlying structural style. Top basement depths estimated from magnetic data - locally constrained from seismic reflection data – reveals the northward-dipping, subsalt basement surface in its depth range of 6-15 km. The basement map reveals the 40-55-km-wide Campeche segment of the 400-km long GOM marginal rift that formed by necking of continental crust adjacent to oceanic crust. The elongate basement depression of the marginal rift combined with the presence “step-up fault” onto Jurassic oceanic crust localizes the thickest depocenter of Bajocian salt and guides the regional curvature of the NE-ENE, downdip salt flow direction. Structural variations of the Campeche passive margin foldbelt that we relate to specific underlying, basement dip domains include: 1) 200-km-wide, updip, extensional zone of listric normal faults detaching on salt (∼3° basement slope); 2) 150-km-wide translational domain zone of folds,

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thrusts, and canopy (∼2° basement slope); and 3) 350-km-wide, downdip, contractional zone of salt-cored folds, and break-thrusts (∼1° basement slope). 1.III Integrated Cretaceous Plate Tectonics and Structural Geology in Southern Mexico Rod Graham (presenter), Imperial College London; J. Pindell, D. Villagomez, Tectonic Analysis; R. Molina-Garza, M. Sierra Rochas, Universidad Nacional Autónoma de México; J. Granath, Granath and Associates The structural evolution of southern Mexico is described in the context of its plate tectonic evolution and illustrated by two crustal scale sections through Cuicateco and the Veracruz Basin and a third across Chiapas. We interpret the Late Jurassic-Early Cretaceous opening of an oblique hyper-stretched basin between the Cuicateco Belt and the Oaxaca Block of southern Mexico where Lower Cretaceous deep-water sediments accumulated. These rocks, together with the hyper-stretched basement beneath them and the Oaxaca Block originally west of them, were thrust onto the Cretaceous platform of the Cuicateco region during the Late -Eocene orogenic event. The mylonitic complex of the Sierra de Juarez represents the hyper-stretched basement, perhaps itself an extensional allocthon. The Chiapas fold and thrust belt is mainly Neogene in age. Shallowing of the subduction angle of the Cocos plate in the wake of the Chortis block suggested by seismicity and migrating arc volcanism, is proposed to play an important role in the development of the Chiapas fold and thrust belt, helping to explain the structural dilemma of a vertical transcurrent plate boundary fault (the Tonala fault) at the back of an essentially dip-slip fold and thrust belt. 1.IV Comments on the Regional Structure of the Salina del Istmo Basin, Southern Gulf of Mexico Daniel Olivares Ramos, Petroleum Geology Consultant Salina del Istmo is a major oil province in the Gulf of Mexico Basin, characterized by its structural complexity related to salt withdrawal and occurrence of some tectonic events in different stages of its geological evolution. Oil and gas fields are mainly located in onshore and shallow waters, where extensive exploration and drilling campaigns have been performed; however, the major portion of this province located in deep waters remains as one of the most important frontier areas of Mexico. Despite the existence of some passive and tectonic events over the time, the current geometry of the basin is mainly related to the Chiapaneca orogeny of Miocene age, which caused the arcuate map view regional structure of the fold and thrust belt. In addition, Miocene to Pliocene extension also modified and produced complexity and favorable trap geometries in some areas of the basin. Understanding the factors that influenced the current structural geometry, identification of internal lineaments, tectonics fronts, variation of deformation axis and dominant tectonic mechanism allow a regional structural classification of styles, that supposes the grouping of areas that would have a common geological evolution and therefore, of the petroleum system. Nevertheless, as is known in the basin, local deformation mechanisms should be taken into account. Then, integration of regional to local structural concepts into the geological and petroleum system models will give important clues about hydrocarbon habitats at “The Place of the Salt” in the southern Gulf of Mexico Basin.

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1.V Balanced Structural Geological Model of the Zaap Field Marlen Medina Macedo, Facultad de Ingeniería, Universidad Nacional Autónoma de México – Spanish Presentation Abstract This study develops a balanced structural geological model of the Zaap field, which was validated using the balanced sections methodology. The study area is located in the Sonda de Campeche, Mexico, it has an economic importance due to the accumulation of hydrocarbons in the conventional reservoirs in this area. 3D time seismic interpretation of 8 stratigraphic units and 10 geologic faults was realized, and it continues with the development of a velocity model and the subsequent conversion to depth of the structural model. The sequential restoration of 3 sections continued, from the current deformation state to the oldest, through the use of the Software Move. Through this analysis it was determined that the sections are balanced, because they are viables and admissibles, and it is accepted that the model has a geometrically valid explanation. According to the results obtained, it is established that the structures in the study area were formed within the framework of different tectonic episodes. The key events that controlled the development of the structures are 1) a tensional period during the Jurassic to the Cretaceous, which resulted in the deposition of large sequences of platform environment carbonates; 2) shortening during the Miocene, which resulted in the development of structural traps from folds related to faults that were formed by the notorious contrast between a baseline horizon of evaporitic rocks and the sedimentary units that overlay it; and 3) tensional events during the Pliocene to the Holocene, resulting in the generation of lystric faults. Finally, the result of the balancing of sections determined the shortening in the study area with an average value of 8.2%. Introduction Petroleum being one of the most significant sources of energy, the study of the geological processes that it experienced from its origin and migration to the structural traps has been essential. On the other hand, understanding the sedimentary history of a reservoir offers many advantages to specialists involved in all stages of the productive life of a field, from exploration to abandonment. The architecture of a basin and the source of the sediments, influence the exploration strategy. The analysis of the deformation of the sedimentary sequences and the balancing of structural sections allows to obtain retro deformable reconstructions of the subsoil that satisfy the principle of conservation of mass. Balanced sections have helped to understand structures and complex relationships in fold and thrust belts. This is of application in the petroleum industry because orogenic belts contain ideal structures to accumulate and produce hydrocarbons. From the foregoing, the importance of keeping in mind a good geological understanding of the area of interest, as well as an adequate understanding of the deformation of the subsoil. It is of interest to reconstruct the geometry of geological bodies deformed, because it constitutes the basis for establishing the sequence of events that affected a region. Another reason is that it serves to determine the exploitation life of a reservoir, being an area of special interest in the modeling of petroleum systems due the reconstruction of the subsoil is used as an input model to predict the maturation, migration and production of hydrocarbons. Location The Zaap Field is geographically located towards north of Ciudad del Carmen, Campeche, in territorial waters of the Gulf of Mexico. Physiographically, it is part of the continental shelf that extends to the 500 m isobath, in front of the states of Tabasco and Campeche, (Figure 1).

10

Figure 1. Location of the Zaap Field (Technical Information Portal - National Hydrocarbons

Commission, 2020). The study area belongs to the Southeast Basin, which is made up of structural tectonic elements considered as the main areas with the presence of hydrocarbons: the Salina del Istmo Basin, the Comalcalco Basin, the Reforma-Akal Fold Belt and the Macuspana Basin to the East (Figure 2).

Figure 2. Southeast Basin (Southeast Basins Geological Atlas, National Hydrocarbons Commission, 2018).

Goals The goals of this study are the deformation analysis of the rocks that make up the Zaap Field, the analysis of the pre, syn, and post kinematic stratigraphic sequences and the reconstruction of the geometry of the geological bodies to determine the structural origin and formation of the reservoirs of interest. The main goal is to generate a balanced structural geological model that shows the deformations and discontinuities obtained through the 3D seismic interpretation of the Zaap Field, which reconstructs the geometry of the formations. Methodology

100

km

0

Zaap

30 km0

Ciudad del Carmen

11

The methodology in this study (Figure 3) began with the information gathering, such as 3D seismic, trajectories and well logs, well tops, check shots and / or TZ. This information was contained and analyzed in a petroleum geological data integration software, which gave the guideline for the beginning of the interpretation of geological formations and faults through a 3D seismic cube in time belonging to the Zaap field. The use of seismic attributes was continued for a better visualization of structural and stratigraphic features, the development of a velocity model and the subsequent time-depth conversion of interpreted horizons and faults. The seismic interpretation of geological formations and faults in depth generated the input data for the stratigraphic and structural analysis in a software developed for structural modeling, as well as, the elaboration of cross sections necessary for the better understanding of the deformation mechanisms in this area, which resulted in the development of the balanced structural geological model of the Zaap Field.

Figure 3. Methodology for the development of the balanced structural geological model of the Zaap Field.

Stratigraphic features The geological evolution of the Southeast Basin was controlled by the opening of the Gulf of Mexico, characterized by an initial rift phase (Early Jurassic). From a sedimentological point of view, this episode was characterized by the deposit of sandy fluvial sediments. During the Middle Jurassic the Proto-Gulf of Mexico was dominated by the deposition of large thicknesses of evaporites due to restricted marine conditions and warm weather. Since the Late Jurassic, the southern Gulf of Mexico has been characterized by the deposition of clastic sediments in an external platform or shallow basin. During the Cretaceous the sedimentary

12

environment changed to a carbonated platform, and the deposit of carbonates, dolomites and shales predominated. The Paleocene was marked by the deposit of dolomitic calcareous breccia from the impact of a meteorite (Chicxulub) towards the Yucatán paleo-platform at the end of the Cretaceous. The Tertiary and Quaternary stages were characterized by the deposition of large amounts of terrigens, composed of bentonite sediments, clays, silts, and sands. The rotation and displacement of the Honduras-Nicaragua microplate (Chortis Block), during the formation of Central America and the Caribbean, resulted in an uplift of the southern region and the Sierra de Chiapas emerged, this represented the source of the sediments to the southern Gulf of Mexico. In Figure 4, a synthesis of the regional stratigraphic framework is shown. Most of the deposits in this geological province are located in breccias from the Upper Cretaceous to Lower Paleocene age and in oolitic limestones from the Upper Jurassic (Pemex Exploration and Production, 2008). The storage rocks of the marine fields, are dolomitized limestones and dolomites of the Kimmeridgiano, the dolomitized limestones and dolomites of the Cretaceous, as well as the dolomitized calcareous breccias of the Lower Paleocene. The oldest producer rocks are Oxfordian sandstones, followed by the Kimmeridgian oolithic banks, the Upper Cretaceous - Paleocene calcareous breccia, the Lower Cretaceous fractured carbonates and finally the Eocene calcarenites.

Figure 4. Regional stratigraphy (National Hydrocarbons Commission, 2014).

13

Structural model based on seismic interpretation The structural model is related to the stresses and deformation that determine the type and orientations of the reservoir structure, it refers to the definition of the geological structure, faults and limits that the reservoir presents, the architecture or skeleton that make it up. The construction of the structural model was carried out by interpreting the seismic events corresponding to horizons and faults. These data were interpolated, taking into account the information from seismic and well tops, which resulted to the development of the surfaces that make up the structural model. The final model is solid, each surface is closed against faults, and it does not present any overlap between surfaces. Each of the originated surfaces served as input data for the construction of the velocity model, and whose purpose was to obtain the in-depth conversion of the seismic information and the validation of each interpreted stratigraphic level. The structural model determined that the structure of the Zaap Field corresponds to an asymmetric anticline with NW-SE orientation, delimited to the north and south by two faults that are parallel to the structure axis, which has an area of approximately 35.6 km2. The fault towards the south is inverse type and presents a dip to the north, it extends for about 7.79 km. The fault to the north is also inverse, unlike the fault described above, its dip is towards the south and has a longitudinal extension of approximately 10 km. The construction of the structural model, initially defined the geometry of the model, such geometry was extended through the entire volume of the seismic cube, a set of 8 surfaces and 10 geological faults. The adjusted and validated surfaces in depth, corresponding to the 8 stratigraphic levels (Sea Floor, Upper Pliocene, Upper Miocene, Lower Miocene, Upper Eocene, Middle Eocene, Cretaceous-Tertiary Breccia (BKS) and Upper Jurassic Kimmeridgian (JSK). Finally, this seismic interpretation represented the input data for the subsequent balancing of sections of the Zaap field.

14

Figure 5. Surfaces (elevation depth) corresponding to: (a) Sea Floor, (b) Upper Pliocene, (c) Upper

Miocene, (d) Lower Miocene.

-100

-100

-100

-100-100

Zaap-3DZaap-4Zaap-8Zaap-27

Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-550

-550

-550

-525

-525

-525

-525

-525

-525

-525

-500

-500

-500

-500

-500

-475

-475

-600

-575

-575

-575

-525

-525

-525

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-950

-950

-950

-950

-950

-950

-900

-900

-900

-900

-900

-850

-850

-850

-850

-850

-850

-800

-800

-1000

-1000

-1050

-1000

-1000

-1000

-1000-100

0

-1050

-950


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1500

-1500

-1500-1500

-1500

-1500

-1400-1400

-1400

-1400

-1400

-1400

-1700

-1600

-1600

-1600

-1600Zaap-3DZaap-4Zaap-8Zaap-27

Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

Map

Surface Sea floor

Scale 1:100000

Author Marlen Medina Macedo

-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00

Elev ation depth [m]

-125

-125-125

-125

-125

-125

-125-125

-125

-125

-125

-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00

Elev ation time [ms]

Mapa

Superficie Piso Marino

Escala 1:100000

Autor Marlen Medina Macedo

(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa

Superficie Plioceno superior

Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa

Superficie Mioceno superior

Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa

Superficie Mioceno inferior

Escala 1:100000


(d)

Elevation depth (m)

Map

Surface Lower Miocene

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125

-125

-125

-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

Map

Surface Upper Miocene

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125-125

-125-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

Map

Surface Upper Pliocene

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125

-125

-125

-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

Elevation depth (m)

Elevation depth (m) Elevation depth (m)

(a) (b)

(c) (d)

15

Figure 6. Surfaces (elevation depth) corresponding to: (a) Upper Eocene, (b) Middle Eocene (CCb), (c) Cretaceous-Tertiary Breccia, (d) Upper Jurassic Kimmeridgian.

-2400

-2400

-2400-2400

-2400

-2250-2250

-2250-2250

-2250-2250

-2250

-2250 -2250

-2250

-2250

-2250

-2100

-2100

-2100-2100

-2100-2100

-2100

-2100

-2100

-2100

-1950

-1950

-2550-2550

-2250

-2400-2400

-2400

-2250

-2100-2100


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-2850 -2850 -2850

-2850

-2850

-2850

-2700-2700 -2700

-2700

-2700

-2700

-2700

-2700

-2550

-2550

-2400

-3000

-3000-3000

-3000

-2550

-2550

-2550

-2550

-255

0

-2550 -2550

-2550

-2550

-2550

-2550

-2550

-2700-2700

-2700

-2700

-2700

-2700

-2400-2400

-2850-2700-2550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

Map

Surface Upper Eocene

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125

-125

-125

-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

Elevation depth (m)

-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


Map

SurfaceUpper JurassicKimmeridgian (JSK)

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125

-125

-125

-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

Map

SurfaceUpper Cretaceousboundary Breccia(BKS)

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125-125

-125-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

-2700 -2700-2700

-2700-2700

-2550-2550 -2550

-2550

-2550

-2550

-2550

-2400

-2400 -2250

-2850

-2850

-2850

-2850

-2400

-2400

-2400

-2400

-2400-2400

-2400-2400 -2400

-2400 -2400

-2250

-2550-2550

-2550-2550

-2550

-2250

-2250

-2700-2550-2400


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

Map

Surface Middle Eocene (CCb)

Scale 1:100000


-3150 -3150 -3150

-3150

-3150

-3150

-3000 -3000 -3000

-3000

-3000

-3000

-3000

-2850

-2850

-2700

-3300

-3300-3300

-3300

-3000

-2850

-28

50

-2850

-2850 -2850

-2850

-2850

-2850

-2850

-3000-3000

-2850

-2850-2850

-2700-2700

-2700-2700

-2700

-3000

-3000-2850


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-4650.00

-4500.00

-4350.00

-4200.00

-4050.00

-3900.00

-3750.00

-3600.00

-3450.00

-3300.00


-125

-125-125

-125

-125

-125

-125-125

-125

-125

-125

-125

-125

-125

-125

-100

-100

-125

-125


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-140.00-135.00-130.00-125.00-120.00-115.00-110.00-105.00-100.00-95.00


Mapa


Escala 1:100000


(a)

-550

-550

-550

-550

-500

-500

-500

-500

-500

-600

-550


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-620.00-610.00-600.00-590.00-580.00-570.00-560.00-550.00-540.00-530.00-520.00-510.00-500.00-490.00-480.00-470.00-460.00


(b)

Mapa


Escala 1:100000


-900

-900

-900

-900

-900

-800

-800

-1000

-100

0

-1000

-1000

-1000

-1000-1000

-100

0


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1080.00-1060.00-1040.00-1020.00-1000.00-980.00-960.00-940.00-920.00-900.00-880.00-860.00-840.00-820.00-800.00


Mapa


Escala 1:100000


(c)

-1500

-1500

-1500

-1500

-150

0

-1375

-1375

-1375

-1625

-1625

-1625

-1625


Zaap-90

574000 576000 578000 580000 582000 584000 586000 588000 590000

574000 576000 578000 580000 582000 584000 586000 588000 590000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

2154000

2156000

2158000

2160000

2162000

2164000

2166000

2168000

2170000

0 1000 2000 3000 4000 5000m

1:100000

-1750.00

-1700.00

-1650.00

-1600.00

-1550.00

-1500.00

-1450.00

-1400.00

-1350.00

-1300.00


Mapa


Escala 1:100000


(d)

Elevation depth (m)

Elevation depth (m) Elevation depth (m)

(c)

(a) (b)

(d)

16

As part of the validation of the interpreted seismic data, a quality control of the faults was performed, making a detailed adjustment with respect to the seismic cube in depth. The result is shown in the Figure 7. With the structural model calibrated in depth, the balancing of sections began.

Figure 7. Set of faults (depth) adjusted and validated in the project. Balancing sections of the Zaap Field The development of this study is based on the application of the sections balancing method, as a geological interpretation technique for the construction of a balanced structural geological model of the Zaap Field, and its validation through an analysis of the structural evolutionary behavior. The use of this methodology allows to validate the previously interpreted structures, searching the least degree of error in the interpretation of the deformed structures that occur in the subsoil, guiding the work towards information that is as close to reality as possible. A practical field of application is presented in exploratory activities in the petroleum industry, for the analysis and understanding of the structural tectonic evolution of hydrocarbon reservoirs. At present, structural geological analysis has been more commonly developed using computer programs; in this case, the program used was ‘Move-Midland Valley’. The balancing and restoration of geological sections are governed by the law of conservation of matter. When carrying out the reconstruction of the deformation of the rocks to their initial state, it must be considered that the original shape is different from the final shape, and that in the same way the initial volume is equal to the final volume, but often the volume does not remain the same, however, the model can be balanced. The reason why there is a reasonable volume deficit may be due to geological processes such as erosion, compaction of the rock by different processes and also by elongation of the structures. Currently, the most used method is the balancing of sections by constant length of lines and areas, coming from geological sections perpendicular to the axis of the structures. The method of balancing sections has improved and has incorporated the development of computational techniques, whose objective is to geometrically restore a section and that complies with certain rules of Structural Geology ensuring that the developed model can have a geometrically valid explanation, so a geological section is considered balanced if it meets a series of conditions, that is, it must be admissible and viable. An ‘admissible section’ is a geological section where the configuration represents the known structures of the region, it respects the structural style observed in the area of interest. A ‘viable

(a) (b)

17

section’ is one that can be restored to not deformed state without gaps or overlaps, that is, structures can be deformed to an initial position. A cross section that is admissible and that is viable is known as a balanced cross section. It is very important to emphasize that a balanced geological section does not represent reality but rather is a model that has a greater chance of being correct because it satisfies the geometric limitations. To build a balanced geological section it is necessary to consider some conditions: • The interpretation must be geologically solid. • The deformation corresponds to a single plane. • The section is in the direction of tectonic transport. • The deformation options (vertical shear, rigid rotation, etc.) must be reasonable and based on our general knowledge of deformation in the given tectonic environment. • The result must be geologically reasonable. For the development of the balancing of sections of the Zaap Field, it was optimal to have as much information as possible, which has been incorporated during the methodology until obtaining in-depth geological information. In this way, there were 8 surfaces and 10 faults from the seismic interpretation. These elements were simultaneously deployed in the Move software, to jointly visualize their distribution in the study area and their spatial relationships. In Figure 8, the 8 surfaces corresponding to Sea Floor, Upper Pliocene, Upper Miocene, Lower Miocene, Upper Eocene, Middle Eocene (CCb), Upper Cretaceous Breccia (BKS) and Upper Jurassic Kimmeridgian, 10 geological faults and the 5 wells used in this project.

Figure 8. Surfaces, geological faults and wells used in this study, viewed from different perspectives in a 3D window.

In Figure 9 a) the distribution of the faults is observed and in Figure 9 b) the surfaces that are affected by these are shown, that is, the faults interpreted in this study, are mainly cutting the surfaces

18

corresponding to the Eocene Middle (CCb), the Upper Cretaceous Breccia (BKS) and the Upper Jurassic Kimmeridgian.

Figure 9. 3D view, a) interpreted geological faults, b) surfaces belonging to the Middle Eocene (ccb), Upper Cretaceous (BKS) and Upper Jurassic Kimmeridgian, cut by the faults.

Three sections were drawn perpendicular to the structure of the Zaap Field (Figure 10). Because the Zaap Field has a very approximate E-W orientation, the 3 sections were drawn with an orientation close to N-S, they present an orientation of 175 °.

Figure 10. View of the Middle Eocene (Ccb) surface showing the lines of the 3 perpendicular sections to the Zaap Field.

The Zaap-3D and Zaap-27 sections cut a portion of the Maloob and Ku Fields, so the sections were extended to the portions of the fields surrounding the Zaap Field, which were inside the seismic cube interpreted. After the sections were created, each element with which they intersected was projected, that is, the surfaces and faults were collected, as shown in Figure 11.

19

Figure 11. 2D sections showing the surfaces and faults projected. Thereby, the balancing of sections began in the 2D module of the software, in which a sequential restoration of the Zaap-3D, Zaap-4 and Zaap-27 sections was developed, which are parallel to each other, as can be seen in the previous figure. In this restoration the intermediate stages were created between the deformed sections and the restored sections. The sequential restoration involved the processes of ‘Decompaction, Isostasy, Unfolding y Move on fault’. Compaction is the change in rock volume due to tectonic subsidence processes, caused by water and sediment loading, thermal subsidence and sediment compaction. In contrast, decompaction assumes that porosity decreases because of these processes and that with the analysis of the history of subsidence, a progressive reversion towards decompaction can be realized. In decompaction analysis, the software provides 4 algorithms. In this study, the Sclater-Christie algorithm was used, which is based on the compaction curve developed in the work of these authors, in which it is assumed that porosity decreases as depth increases (compaction) and on the other hand, porosity increases according to the decrease in depth (decompaction), in this way, the compaction of the sediments, and the variations in porosity can be modeled by an exponential with depth. The parameters used were the compaction curve with the Sclater-Christie algorithm, initial porosity parameters of 56%, a depth coefficient of 0.39 km-1 and a grain density of 2680 kg/m3. It should be noted that this process also considers the database of stratigraphic units and their rock properties for the calculation of decompaction. Other parameters were used, Airy Isostasy and Sub Marine Load. Typically, sections of hundreds of km would be suitable for Flex Isostasy modeling. In this thesis project, the Zaap-4 section has an extension of 7.5 km, the Zaap-3D section measures 11.7 km and the Zaap-27 section has an extension of 13.6 km. Due to this, Airy Isostasy was used for isostatic analysis, keeping in mind that Airy Isostasy is more sensitive to thickness variations. 'Unfolding' another of the developed processes, which was used in the stages during the sequential restoration of the 3 sections to eliminate the deformation of the folds. The algorithm ‘Flexural Slip 2D’ was used, which does a parallel sliding between the layers. Continuing with the development of the sequential restoration of the 3 mentioned sections, the 'Move on Fault' process was used to restore the faults. When the fault is of the propagation type, the 'trishear' algorithm is used, which is a method that is related to folds by propagation of soft faults and rounded hinges.

20

With the development of the previously described processes and the use of the associated algorithms and parameters, 10 restoration stages were obtained for the Zaap-4 section, 17 stages for the Zaap-3D section, and 18 stages for the Zaap-27 section, obtaining the balancing of these 3 sections by sequential restoration, from the current state of deformation to the oldest. Even though the restoration method is from current to oldest, the process of evolution of the sections is described below from oldest to present for ease of understanding. As a summary, only the result of the balancing of the Zaap-27 section is shown in Figure 12.

Figure 12. Sequential restoration of the Zaap-27 section.

21

In this way, the evolution of the observed events in the 3 structural sections begins with the oldest unit, which corresponds to a Callovian age, in which an invasion of marine waters with low depth was carried out and that favored the deposit of evaporitic sequences. This unit was not cut by any wells used in this study, however it is derived from seismic interpretation. This unit represents the detachment on which folds and faults developed in the later formations to this autochthonous salt. After the Callovian salt deposit, the invasion by marine waters progressed, very wide platforms developed during the Oxfordian, where the circulation of the waters was very restricted, and they were limited towards the sea by long oolites bars. These conditions of slow and continuous subsidence prevailed during the Kimmeridgian; In Figure 12, the deposit of this unit is shown, represented by the blue horizon, which correspond to wackestone, packstone and grainstone of ooids facies, as well as dolomitized sequences. These sequences have been identified as hydrocarbon storage rocks in the Zaap Field. The Late Jurassic period was characterized by being a time of tectonic tranquility in which a slow subsidence propitiated the necessary conditions for the deposit of carbonates and alternated calcareous muds. Thus, the Tithonian was deposited, this unit is one of the most significant from the point of view of the petroleum system, because of is the most important source rock in the marine area of this region, it is composed of clayey limestone with intercalations of lightly calcareous bitominous shales; its organic content is made up of algal material, plant and animal remains. Regional tectonic stability continued during the Cretaceous, which represents a platform sedimentary sequence, with lithofacies of dolomitized clay carbonates. BIg carbonate deposits developed during the Lower Cretaceous and the Upper Cretaceous, was presented a growth of the carbonate platform and the deposit of breccias and turbiditic flows on the continental slope, whose predominant lithofacies are dolomites, clayey limestones and dolomitized breccias. The carbonate sedimentation of the Upper Cretaceous represents an important hydrocarbon producing unit in the region. During the Cenozoic, a major change in the tectonic regime took place, which caused a notable change in sedimentation, represented by the lithological contrast between the Cretaceous carbonates and the powerful Tertiary column of terrigens. The interpreted Tertiary horizons in this study were the Middle Eocene (CCb calcarenites), Upper Eocene, Lower Miocene, Upper Miocene, Upper Pliocene, and Recent. The Eocene, is mainly composed of shales and calcareous siltstones alternating with layers of bentonite shales. The Middle Eocene is also of economic interest in the Zaap Field, as well as in neighboring fields, due to it represents a producer interval constituted by a calcareous body of grainstone and packstone of bioclasts and intraclasts with oil impregnation. The deposit of this unit can also be seen in Figure 12. Later, during the Oligocene the deposit of clastic sediments continued and the same sedimentary patterns continued during the Lower Miocene, but in the Middle Miocene the formation of folds began in response to the beginning of a compressive pulse of the Chiapaneca Orogeny, folding the units of the Jurassic and Cretaceous mainly, with a level of detachment at the top of the Callovian salt and a vergence towards the north, developing the folds in this region and the formation of reverse faults. The direction of tectonic transport was towards the north, in response to the compressive stress of the Chiapaneca Orogeny. In the first place the Ku fold was developed, involving the deformation of

22

the Jurassic, Cretaceous and Paleogene with detachment in the Callovian salt and continuing with the formation of reverse faults whose displacement corresponds to the same direction of tectonic transport, thus defining the direction of synthetic faults 1 and 2 in the study area, as can be seen in Figure 12. The compressive stress continued, creating the Zaap fold also with a detachment level on top of the Callovian salt. The compressive stress led to the formations from a ductile to a fragile behavior, developing the inverse faults that currently delimit the Zaap Field: Fault 3 is the main fault, Fault 4 is secondary synthetic and Fault 5 is antithetical, that is, it has a displacement opposite that of the main fault. Finally, the Maloob fold was formed as shown in Figure 12 and the inverse faults that delimit it, Fault 6 is the main fault, Fault 7 is secondary synthetic and Fault 8 is antithetical. After the contractional deformation of the Chiapaneca Orogeny event, a large contribution of clastic sediments from the Chiapaneca Orogeny began, it continued during the Pliocene and Pleistocene, which caused the deposit of several kilometers of sediments, whose overload began to generate large extensional growth faults. It should be noted that this study did not interpret faults at the Tertiary level, because these growth faults have a NE-SW orientation, being almost perpendicular to the direction of the folds formed during the Chiapaneco event, so their visualization from the seismic lines 'random lines' was not possible. The current structural arrangement shows each one of the deformation events that the region has developed through geological time. Nowadays, the structural geometry of the Zaap Field, as well as the surrounding fields, with which it integrates the Ku-Maloob-Zaap complex, suggests that it corresponds to faulted detachment folds, and that they were formed by the noticeable contrast between the Basal horizon of evaporitic rocks and the sedimentary units with greater competition that overlay it. Is also associated a deformational behavior that progressively goes from a detachment folding to a faults propagation. The structures of this area were formed within the framework of different tectonic episodes; however, the key events that controlled the development of the structures are 1) an extensional period during the Jurassic through the Cretaceous, resulting in the deposit of carbonate sequences from the platform environment; 2) shortening during the Eocene-Miocene, which resulted in the development of structural traps from fault-related folds; and 3) extensional events from Pliocene to the Holocene, resulting in the generation of normal lystric faults that, although not be adequately observed in the balanced sections, could be identified in the 3D seismic of the study area. Analysis and validation of balanced sections of the Zaap Field The geometric restoration of the balanced sections Zaap-4, Zaap 3D and Zaap-27, satisfies the rules of Structural Geology, verifying that the sections are viable and admissible and it is accepted that the model has a geometrically valid explanation. The sequential restoration of the sections showed that they are ‘admissible’ because their structural configuration represented the known structures of the region through 3D seismic interpretation and respected the structural style. On the other hand, they are 'viable' sections because they managed to be restored to not deformed state, removing the effects of deformation from an initial position. Because of this, the 3 cross sections are balanced.

23

The balanced structural geological model of the Zaap Field and the surrounding fields (Ku and Maloob), met the conditions to consider a valid balanced model, that is, the interpretation was based on a solid structural model, the sections were oriented in the direction of the tectonic transport and the balancing result is geologically reasonable. Below is shown the analysis of the Zaap-27 section, in their current deformation state and the balanced section resulting from the sequential restoration before shown. In Figure 13, the Zaap-27 section is shown in its current deformation state, it is observed the structural configuration of the Zaap field and the surrounding fields (Maloob and Ku). The analysis of thicknesses and line lengths of each formation was developed. The extension of this section is 13.6 km and it has an orientation of 177 °.

Figure 13. Current deformation state of the Zaap-27 section and the analysis of thicknesses and line lengths.

Finally, it is observed in Figure 14, the Zaap-27 balanced section, this was restored to an initial not deformed state, and its restoration by line length showed that the final values after the section balanced, are approximate to the values of line length in the current deformation state, so it is considered that there are not changes in the lines length. On the other hand, restoration by areas also showed a difference in the final thicknesses, but they are considered acceptable, because of they are explained by means of compaction effects. This analysis verifies that this section is balanced, because it is viable and admissible, and it is also accepted that it is a geometrically valid section.

24

Figure 14. Balanced Zaap-27 section and analysis of thicknesses and line lengths. Once the balanced sections have been obtained, the shortening calculation is quite simple and is the result of the difference in length between the balanced sections and the deformed sections, using the formula: S= ((l0-lf)*100)/l0 Where, S is the shortening value, l0 is the length of the balanced section, that is, in the initial state before deformation, and lf is the length of the section in its deformed state. In this way it can be established that the Zaap-4 section has a shortening of 6.7%, the Zaap-3D section has a 9.4% shortening and the Zaap-27 section presented a shortening of 8.6%. Conclusions 9 stratigraphic units and 10 faults were obtained from the 3D seismic interpretation (time domain), these elements integrated the construction of the structural model, which through the development of a velocity model, the conversion to depth of these elements was done. Due to the seismic information also included the structures of two fields surrounding to the Zaap Field (Maloob and Ku), it was decided to expand the interpretation to include these structures. Thereby, starting from the in-depth seismic interpretation, a balanced structural geological model of the Zaap Field was built and was validated using the balanced sections methodology. The balanced structural geological model is made up of 3 sections whose direction of each of these sections was drawn close to 180 °, being perpendiculars to the Zaap Field anticline. The model is also make up by 9 stratigraphic units (from the detachment represented by Callovian salt to the Sea Floor), 3 folds (Ku, Zaap and Maloob) and 8 inverse faults (6 synthetic and 2 antithetical). It was determined that the first fold to form was the Ku Field fold and its 2 associated synthetic faults (Fault 1 and Fault 2). Later, the Zaap Field fold and the faults that currently delimit the field (Synthetic Faults 3 and 4, and Antithetical Fault 5) were formed. Finally, the Maloob Field fold and its related faults (Synthetic Faults 6 and 7, and Antithetical Fault 8) were developed. These structures were the result of tectonic transport in response to compressive event during the Chiapaneca Orogeny during the Eocene-Miocene, folding the Jurassic, Cretaceous and Paleogene formations.

25

The shortening that took place during the Chiapaneca Orogeny, resulted in the development of structural traps from the fault-related folds. The calculation of the shortening of each section established that the Zaap-4 section presented a shortening of 6.7%, the Zaap-3D a value of 9.4% and the Zaap-27 section developed a shortening of 8.6%, so it is suggested that displacement is different according to the position of each section, showing greater displacement in the center of the Zaap fold and less in the ends of it. The result of the balancing of sections determined the shortening in the study area with an average value of 8.2% The result of the sequential restoration of the 3 sections, Zaap-4, Zaap 3D and Zaap-27, it was established that they are balanced sections, because they satisfy the rules of Structural Geology, where it was found that they are ‘viable’ and ‘admissible’ and it is accepted that the model has a geometrically valid explanation. The study area, in addition to geological interest, has an economic importance for Mexico due to the accumulation of hydrocarbons in the conventional reservoirs of the Upper Jurassic Kimmeridgian (JSK) formations, Upper Cretaceous breccia (BKS) and Middle Eocene calcarenites (CCb). The source rock par excellence in this region belongs to the Upper Jurassic Tithonian formation. The model developed here suggests that the hydrocarbons generated in the Tithonian were stored in the structural traps formed by the Ku, Maloob and Zaap folds and the migration routes formed by the reverse faulting. 1.VI Paleomagnetism of the Barremian Chivillas Formation, NW Cuicateco Terrane: Evidence for a final Stage Opening of the Gulf of Mexico? Bernardo Ignacio García Amador (presenter), B. Ortega-Guerrero, L. Alva-Valdivia, Instituto de Geofísica, Universidad Nacional Autónoma de México The western region of the Gulf of Mexico is characterized by a highly relevant tectono-sedimentary record, both for the petroleum system and for understanding the Pangea fragmentation. One of the key pieces to understand the Jurassic–Cretaceous tectonic evolution of the region is the Cuicateco terrane, distributed in the Puebla, Oaxaca, and Veracruz states. The Cuicateco terrane is considered an inverted basin limited by the Oaxaca and the Vista Hermosa faults. The tectonic evolution of this basin is divided into two phases: Hauterivian–Aptian extension; and Cenomanian–Paleocene shortening. During the extensional phase, the Chivillas Formation was deposited. This Formation is made up of deep-marine sedimentary rocks, with at least eight facies associations, including interstratified lava flows and pillow lavas. The origin and evolution of this basin have generated a discussion of a possible link with an Early Cretaceous final stage opening of the Gulf of Mexico. However, it is still necessary to solve this basin in a structural and tectonic way. This work presents the paleomagnetic and rock-magnetic results of the “undeformed” portion of the Chivillas Fm., from the lava flows and pillow lavas lithofacies, as well as preliminary results from fine-grained turbidite facies. Our results indicate a clockwise rotation of ~20° with respect to North America. This suggests us to two potential scenarios: (1) strain partitioning in a region within the dextral lateral fault system; or (2) blocks rotation by the shortening phase in the Late Cretaceous.

26

SESSION II: SEDIMENTOLOGY, STRATIGRAPHY AND BIOSTRATIGRAPHY 2.I The Importance of Regional to Basin-scale Paleogeographic Reconstructions for Exploration in Offshore Mexican Basins John W. Snedden, Institute for Geophysics, The University of Texas at Austin Pre-drill prediction of reservoir presence and quality in underexplored areas of the southern Gulf of Mexico is best supported by detailed paleogeographic reconstructions of source terranes, fluvial delivery systems, and depositional “sinks”. This is demonstrated by examples from both Mesozoic and Cenozoic depositional systems. For Mesozoic depositional systems like Mexico Oxfordian reservoirs, reconstructions are founded upon plate tectonic restorations, detrital zircon geothermochronology, and detailed sedimentological analyses. This differs from prior local studies by placing the Bacab Sandstone, a major reservoir in offshore Mexico, in a larger basin- to regional-scale context. The modeled aeolian sand sea (erg) is comparable to the Norphlet of the northern Gulf. Detrital zircon U–Pb analyses, however, indicate that different source terranes supplied siliciclastics to the Bacab and Norphlet sandstones. Results from Balam field indicate that the Mayan (Yucatán) Block is the primary terrane for the Bacab, separate and distinct from Norphlet reservoir Appalachian (Laurentian) to Pan-African source terranes. Dimensional considerations, such as contrasting ratios of aeolian source area to erg deposition also support the notion of non-continuous deposition across the Yucatan margin. For Cenozoic depositional systems, predictions of submarine fan run-out length are critical, given a limited number of deepwater wells drilled in the Campeche salt basin and Perdido fold belt. One approach is to employ empirical scaling relationships established from global datasets and calibrated against Cenozoic systems of the northern Gulf. Examples from the Mexican Ridges, Veracruz Trough, and Burgos basin illustrate application of predictive source to sink scaling relationships at the exploration scale. 2.II New Perspectives on the Todos Santos “Group”, the Chontal an Allochthon, and the Rotation History of the Chiapas Massif, Southern Mexico Roberto Molina Garza (presenter), Centro de Geociencias, Universidad Nacional Autónoma de México; J. Pindell, Tectonic Analysis The Todos Santos Group of southern Mexico has been interpreted as the record of rifting that predates opening of the Gulf of Mexico (Blair, 1987). Outcrops of the Todos Santos Group form an apparently continuous belt from the Zongolica region in the west to the Guatemala-Mexico border in the east (Figure 1). However, this belt consists of three dissimilar successions: (1) at the type locality in the Altos Cuchumatanes, Todos Santos is an Upper Jurassic-Lower Cretaceous succession at the base of a Cretaceous transgressive sequence; (2) in the Veracruz basin and around the Mixtequita block, the Valle Nacional formation of the Todos Santos Group is an Upper Triassic succession deposited in continental extensional basins; and (3) in Chiapas the Jiquipilas formation of the Todos Santos Group is a Jurassic synrift succession. For this reason Todos Santos strata are better understood if raised to the group rank (Molina-Garza et al., 2020a).

27

Figure 1. Outcrop belt of the Todos Santos Group in southern Mexico over a simplified terrane and basement element map of southern Mexico. Town abbreviations: Oa = Oaxaca City; TG = Tuxtla Gutiérrez; VN = Valle Nacional; SJR = San Juan del Río; MR = Matías Romero. Terrane abbreviations: MT = Mixteco Terrane; OT = Oaxaca Terrane; CB = Cuicateco Belt; CM = Chiapas Massif; MB = Mixtequita Block. Other abbreviations: TCZ = Tierra Colorada shear zone; JT = Juchatengo shear zone; TSZ = Tonalá shear zone; GMP = Guerrero-Morelos platform. Small triangles are volcanic centers. Modified from Molina-Garza et al., 2020a. In the northern flank of the Chiapas massif, Todos Santos strata are largely undeformed. They overlie volcanic rock of Lower to Middle Jurassic age and volcanic arc chemistry of La Silla Formation (Godínez-Urban et al., 2011a); they record deposition of volcaniclastic strata during the initial rift stages before basement is exposed. Here, the Todos Santos Group includes the Jiquipilas formation (alternate type Todos Santos section of Richards, 1963) that is subdivided into the El Diamante, Jericó and Concordia members (Jericó region of Figure 1); these units record the rift initiation, rift climax, and post-rift stages of basin evolution. Also, paleomagnetic data from El Diamante member and underlying volcanic rocks of La Silla Formation indicate about 40º of counter-clockwise rotation of the Maya block (Godínez-Urban et al., 2011b). The Jericó member is interpreted as a large axial-rift fluvial system that flowed to the northeast (restored for paleomagnetically determined rotation) toward the paleo-Gulf of Mexico, and was fed by conglomerates derived from the rift shoulders (Blair, 1987; Molina-Garza et al., 2020). The Jericó member is mainly composed of arkose and polymictic conglomerate. The transition from the Concordia member to the San Ricardo Formation records the earliest open marine incursion in the Chiapas massif region. Outcrops of the Todos Santos Group in the Veracruz basin, as wells as south of the Mixtequita block, and southeast of the Chiapas massif are characterized by Triassic (U-Pb zircon) maximum depositional ages, negligible volcanic detritus, and intense deformation caused by emplacement of

28

the Chontal allochthon in the Paleogene. These strata are assigned to the Valle Nacional formation, consisting of fluvial strata deposited by paleo-SW flowing rivers (restored for paleomagnetically determined rotation). Limited paleomagnetic data for the Todos Santos Group in the Tehuantepec region near Matías Romero are interpreted to record counter-clockwise rotation similar to that observed in Chiapas. Dual polarity magnetizations and a positive fold test suggest a primary origin for the remanent magnetization of the Valle Nacional. An Early Jurassic pluton intrudes the Valle Nacional formation near San Juan del Río, Veracruz. The Valle Nacional and Jiquipilas basins are thus distinct and were juxtaposed by the Western Gulf Transform, which appears to be locally exposed as the Petapa fault in the Tehuantepec region (Figure 1). The Petapa fault developed mylonites with right-lateral kinematics in Todos Santos redbeds. Events responsible for deformation of the Todos Santos Group vary along strike of its outcrop belt. In the western outcrops in the Veracruz basin and Cuicateco belt deformation is manifested as northeast verging folding and thrusting attributed to Laramide age orogenesis. In the southern Tehuantepec region deformation of the Todos Santos Group is attributed to emplacement of the Chontal allochthon in the Paleogene. The Chontal allochthon is an oceanic element that includes mid-ocean ridge basalts and turbidites of the Upper Cretaceous with sediment derived from nearby continental elements and a Late Cretaceous arc. Paleomagnetic data and paleo-tectonic reconstructions suggest that emplacement of the Chontal allochthon may be related to interaction between the Chortis block and southern Mexico (Molina-Garza et al., 2019). In Chiapas, mild deformation of the Todos Santos Group north of the Chiapas massif is attributed to the Miocene Chiapanecan orogeny. This event has been recently interpreted as the result of transpression linked to eastward displacement of Chortis (Molina-Garza et al., 2020b). Paleomagnetic data for the mid-Eocene Bosque formation in the Chiapas central Depression (near Tuxtla Gutiérrez, Figure 1) have been interpreted to indicate about 20º of clockwise rotation of the Chiapas Massif with respect to the Maya block (Molina-Garza et al., 2020b). Rotation may have been caused by basal traction between the underriding Cocos Plate and the massif’s continental lithosphere. Restoring 20º of post-Eocene clockwise rotation has important implications for previous interpretations of paleomagnetic data for the Todos Santos Group and the San Ricardo Formation (Figure 2). First, the Triassic age paleopole for the Valle Nacional formation and the Lower-Middle Jurassic age paleopole for the La Silla Formation and El Diamante member of the Jiquipilas formation (Godínez et al., 2011b) indicate a mutually similar amount of rotation with respect to the North America reference, suggesting that the Mixtequita block rotated with the Maya block in the Jurassic. Secondly, post-Eocene rotation suggests that rotation of the Maya block may have continued to occur after deposition of the Tithonian portion of the San Ricardo Formation (Guerrero et al., 1990).

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Figure 2. Summary of paleomagnetic data for the Maya Block. Poles for the Chiapas massif (CM and CM-r, Molina-Garza et al., 1992), the Todos Santos Group in the Jericó (Concordia) area (TS; Godínez et al., 2011a), Custepec dikes (CU; Godínez et al., 2011a), and the San Ricardo Formation (SR and SR-r; Guerrero et al., 1990). These poles have been restored for 20º of post Eocene clockwise rotation of the Chiapas Massif (after Molina-Garza et al., 2020b). We also show a revise paleopole for the Todos Santos Group in the Matías Romero (MR) region in the Mixtequita Block, where is it assumed to be of Triassic age. The revised paleopole, including three new localities near Guichicovi, is at 37.3ºN-167.2ºE; A95=181). Dotted lines represent the angular distance of the poles to the North American reference apparent polar wander path after Torsvik et al. (2012) for the Mesozoic (ages in millions of years).

References Blair, T.C., 1987, Tectonic and hydrologic controls on cyclic alluvial fan, fluvial, and lacustrine rift-basin sedimentation, Jurassic–Lowermost Cretaceous Todos Santos Formation, Chiapas, Mexico: Journal of Sedimentary Petrology, v. 57, p. 845–862. Godínez-Urban, A., Lawton, T.F., Molina-Garza, R.S., Iriondo, A., Weber, B., and López-Martínez, M., 2011a, The Jurassic volcanic and sedimentary rocks of La Silla and Todos Santos formations, Chiapas: Record of Nazas arc magmatism and rift basin formation prior to opening of the Gulf of Mexico: Geosphere, v. 7, p. 121–144, https://doi.org/10.1130/GES00599.1. Godínez-Urban, A., Molina-Garza, R.S., Geissman, J.W., and Wawrzyniec, T.F., 2011b, Paleomagnetism of the Todos Santos and La Silla Formations, Chiapas: Implications for the opening of the Gulf of Mexico: Geosphere, v. 7, p. 145–158, https://doi.org/10.1130/GES00604.1. Guerrero-García, J.C., Herrero-Bervera, E., and Helsley, C.E., 1990, Paleomagnetic evidence for post-Jurassic stability of southeastern Mexico: Maya Terrane: Journal of Geophysical Research, v. 95, p. 7091–7100, doi:10.1029/JB095iB05p07091. Molina Garza R.S., R. Van der Voo, and J. Urrutia-Fucugauchi, Paleomagnetism of the Chiapas massif, southern Mexico: evidence for rotation of the Maya Block and implications for the opening of the Gulf of Mexico, Bulletin of the Geological Society of America, 104, 1156-1168, 1992.

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Molina Garza, Roberto S., Douwe J.J. van Hinsbergen, Lydian M. Boschman, Robert D. Rogers, and Morgan Ganerød, 2019, Large-scale rotations of the Chortis Block (Honduras) at the southern termination of the Laramide flat slab, Tectonophysics, v. 760, p. 36-57; https://doi.org/10.1016/j.tecto.2017.11.026. Molina Garza, R.S, T. F. Lawton, J. R. Barboza Gudiño, M. I. Sierra-Rojas1, A. Figueroa Guadarrama, Jim Pindell, 2020a, Geochronology and correlation of the Todos Santos Group, western Veracruz and eastern Oaxaca states, Mexico: Implications for regional stratigraphic relations and the rift history of the Gulf of Mexico, in: "Southern and central Mexico: basement framework, tectonic evolution, and provenance of Mesozoic-Cenozoic basins", edited by U. Martens and R.S. Molina-Garza, GSA Special Paper 546, DOI: https://doi.org/10.1130/2019.2546(6). Molina-Garza, R.S., Pindell, J., Montaño-Cortés, P.C., 2020b, Slab flattening and tractional coupling drove Neogene clockwise rotation of Chiapas Massif, Mexico: Paleomagnetism of the Eocene El Bosque Formation. J. South Am. Earth Sci., v. 104, https://doi.org/10.1016/j.jsames.2020.102932. Richards, H.G., 1963, Stratigraphy of earliest Mesozoic sediments in southeastern Mexico and western Guatemala: American Association of Petroleum Geologists Bulletin, v. 47, p. 1861–1870. Torsvik, T., Van der Voo, R., Preeden, U., Niocaill, M.C., Steinberger, B., Doubrovine, P.V., Van Hinsbergen, D.J.J., Domeier, M., Giana, C., Tohver, E., Meert, J., McCausland, P.J.A., Cocks, R., 2012, Phanerozoic polar wander, palaeogeograghy and dynamics: Earth-Science Reviews, 114, 325-368.

2.III Paleo-Canyons and Hydrocarbon Trapping in the Tampico-Misantla Basin, Eastern Mexico Stephen P. J. Cossey, Cossey and Associates Inc. (presenter); Mark R. Bitter, Marbit Geoconsulting Six major paleo-canyons have been identified in the Paleogene sedimentary sequences along the western flank of the Tampico-Misantla basin in eastern Mexico. These have all been documented by outcrop sampling and also extend into the subsurface. Other paleo-canyons have been documented by previous authors in the deep subsurface portion of the basin. These paleo-canyons were formed during the late Paleocene (~56 Ma) and cut into thick unconsolidated and consolidated Paleocene and Cretaceous sediments. All the paleo-canyons are identified as incursions of the revised Paleocene/Eocene contact. The northernmost Acatepec paleo-canyon was filled with more than 700m of slumps, pebbly-mudstones, channel, and channel-levee sediments. Part of the sequence contains four extensive paleo-karsted intervals that are interpreted to have been formed by hypogene processes. The San Lorenzo paleo-canyon contains a thick mass transport complex (MTC) above its erosional base. The southernmost Nautla paleo-canyon has been documented by previous authors in the subsurface, but we have now identified the canyon-fill sediments in outcrop. At all the studied outcrop locations, the canyon-fill sediments are deepwater sequences. The subsequent deposition of MTCs after the ~56 Ma unconformity created seals for the sub-cropping reservoirs of the Chicontepec Formation in the paleo-canyon to the southwest of Poza Rica. The MTCs also form the seal at the San Andres field where the erosion has removed the entire Cretaceous section. The trapping mechanism for the Agua Fria field is interpreted as a canyon truncation trap and for the Coapechaca and Tajin fields as canyon-fill traps. The paleo-canyons persisted until at least the uppermost middle Eocene (~38 Ma) because a large submarine slide is documented in the basin. They may have persisted as topographic lows throughout the Neogene because they also coincide with the location of Pliocene basalt flows and present-day fluvial systems.

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2.IV Near Shore Untapped Hydrocarbon Potential from Burgos to Southeast Offshore Mexico Karyna Rodriguez (presenter), N. Hodgson, Searcher The Mexican Gulf of Mexico has 56 BBOE cumulative production, proven reserves of around 80 BBOE and it is estimated to still hold significant prospective conventional resources of around 52 BBOE (www.pemex.com). In 2013 Mexico opened to participation from international exploration players, generating a lot of interest and resulting in several major seismic acquisition campaigns to support the licence rounds held between 2014 and 2018. In 2017 the Zama discovery was a great example of utilizing modern, high fidelity seismic processing to realize the potential of the extremely prolific Sureste Basin. To the northwest of the Sureste Basin, the much less explored Cordilleras Mexicanas, Tampico Misantla and Burgos offshore Basins lie in an arc stretching all along the East Coast of Mexico. A unique sequence of tectonic events combined with the stratigraphic evolution, has resulted in multiple stacked play systems in both older carbonate systems and younger clastic deposits. In 2016, whilst overcoming the extreme operational challenges of acquiring in water depths between 20 and 2,000 m, a nearshore regional grid of modern 2D seismic was recorded across all these basins.The acquisition with longer streamer allows more precision in the use of far-offsets to find hydrocarbons directly – something still difficult to do with legacy reprocessing. With excellent imaging across all the Mexican GoM, the survey provides modern, high quality imaging of the most prospective nearshore areas. Nearshore offshore Mexico, there remain significant unexplored prolific play fairways, to be presented here, with abundant undrilled amplitudes, salt-related traps and undrilled carbonate build-ups. 2.V Sedimentologic Characterization of Sandstones in Chicontepec Basin José Aurelio España Pinto (presenter), D.M. Anaya-Saldívar, J.A. España-Pinto, R. Nicolás-López, O.C. Valdiviezo-Mijangos y J.M. Espinosa-Ortega, Instituto Mexicano del Petróleo Exploration and the exploitation of the Chicontepec Basin have raised several unsolved problems and challenges through its prospecting history; the main difficulties are related to its geologic complexity, such as low permeability, compartmentalization, and higher shale volume. These problems complicate the identification and delimitation of sandstone bodies that act as reservoirs.This work presents a new method for sedimentary characterization using seismic inversion and logs data for its interpretation through rock physics templates (RPT). Template construction was done using an application that considers a multicomponent micro-mechanics model that involves mineral’s and the fluid’s effective properties to calculate the elastic response of mineralogical mixtures in different proportions. The elastic response obtained and plotted like RPT is related to a known lithological classification. The RPT is overlapped to sonic well logs and seismic inversion data cross plot in order to make the geological interpretation; this tool and method let us find and characterize stratigraphic units in a lithological and sedimentological sense.Four prospective levels were recognized in the study area. They illustrate the deposit’s architecture and sedimentary evolution. On two lower levels sinuous channels and meandric forms with NW-SE direction and associated with splay were recognized; at the same time, on one upper-level thin channels that lead to sheet sand lobes and clustered lobes complexes were found. Comparing the obtained maps in this work with seismic attributes’ maps, our results show better resolution in geometries, extension, and identification of potential reservoirs, leading to a greater certainty to the interpretation and construction of geologic models.

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2.VI Bioevents and Microfacies from the Upper Jurassic Tithonian (Pimienta Formation) in the Northeast of Mexico: Biostratigraphic, Paleonvironmental and Economic Implications Baltazar Hernández Sánchez, Petróleos Mexicanos (PEMEX) – Spanish Presentation Introduction The main studies of the Tithonian sequence (Upper Jurassic), from the southern state of Tamaulipas are those carried out by PEMEX in the years 2011, 2012, 2015, 2016 and 2017, especially plays studies focused on the characterization and geological evaluation and economic feasibility of exploring and exploiting the hydrocarbon deposits stored in the Pimienta Formation, these studies encompass a series of disciplines in the field of geosciences, however studies related to the biostratigraphy of the area are scarce. This situation motivated the development of this work, which characterizes the conditions biostratigraphic and paleoecological of the Tithonian, in order to generate a framework biochronostratigraphic that contributes substantially to the interpretation of models stratigraphic and sedimentological that add value to the exploratory process of the area inquestion. Location of Area of Study The study area is located in the northeast of Mexico in the coastal plain of the Gulf of Mexico, in the States of Tamaulipas and Nuevo León, limited to the north by the town of Cruillas at parallel 25 ° 00 '00 "North Latitude where it is located, to the south on parallel 24 ° 00‘ 17”, to the west with the Sierra de San Carlos Cruillas-Arco de Tamaulipas and to the east the coast of the Gulf of Mexico.

Figure 1.- Geographical location of the study area. Material and Methods A total of 7 cores (120 thin sections) were studied, consisting mainly of black clay limestone and shale and black calcareous siltstone horizons with a carbon look, the classification of sedimentary textures used was the one proposed by Dumhan, (1962).

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For taxonomic identification the criteria established by Loeblich& Tappan (1988) were used and Ivanova (1997), the stratigraphic reaches of the microfossils come from the standard PEP-IMP compound, (2004), the biozoning used was that established by Ornelas et al. (2002) & (2004).

Figure 2.- Work flow diagram

Results Micropaleontological Content The microfossil assemblage consists mainly of abundant and not very diverse groups of calpionellids, saccocomidos, stomiosphaerids, calcareous nanoplankton, benthic microforaminifers and radiolarians (Figure 3).

Figure 3.- Fossil association and stratigraphic range

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Bioevents All horizon bioevents of first and last appearance, abundance peaks of microfossil groups and presence of ammonites were documented; these bioevents were integrated with data from well logs, lithological column, deposit cycles and paleoenvironments (Figure 4).

Figure 4.- Bioevents identified in the nuclei analyzed and integrated into well data and the

biozoning proposed by Ornelas et.al.2004 Bioevents Correlation All bioevents observed in the cores and cutting from wells A, B, C, D, E, F and G, have a wide biostratigraphic correlation at the regional level (Figure 5), most of biofacies belong to external rampand basin deposits during the Tithonian.

Figure 5.- Correlation of identified bioevents.

Microfacies Association The sedimentological characteristics of the microfacies associations identified in the analyzed material are described below.

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Figure 6.- Sedimentological characteristics of the microfacies identified in Tithonian (Upper

Jurassic). Sedimentary Model The interpretation of microfacies, allows defining a sedimentary model of External Ramp and Anoxic Basin, the detail of the profile is presented below (Figure 7).

Figure 7.- Idealized sedimentary model of the Tithonian (Upper Jurassic).

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Economic Implications Microfacial analysis indicates characteristic sedimentary facies of external ramp and basin environments (<200 m deep) with high organic matter content, associated with high responses of the gamma ray log curve and total organic carbon content (TOC) they follow that the microfacies associations JST-2, JST-3 and JST-4 were deposited under anoxic conditions, thus making them attractive horizons for the exploration and exploitation of deposits under the concept of unconventional. This play is currently in the early stage of exploratory studies, but compared to other hydrocarbon producing units under the same concept, it offers broad development expectations (Figure 9), on the other hand, wells drilled with this economic objective have shown to have very prospective characteristics, particularly to the discovery of light and condensed oil hydrocarbons, this associated with the brittle nature of this sedimentary sequence (PEMEX, 2018 and Granados et al. 2018).

According to the exploratory studies carried out by PEMEX-PEP (2011 and 2017), this play has a wide economic prospect that covers tens of square kilometers, it is vitally important to design a specific strategy to continue evaluating this sedimentary sequence that creates new possibilities of exploration and exploitation incorporating oil and gas reserves for Petróleos Mexicanos in the short term. Conclusions

• The interpretation of bioevents allowed dating the sequence as Tithonian (Upper Jurassic).

• The association of microfacies and the paleoecological analysis suggest that the deposit of the sediments corresponds to the paleoenvironment of the external ramp and the anoxic basin.

• The bioevents described here correspond to the biozones of Crassicollaria, Saccocoma arachnoidea and Parastomiospharea malmica, according to the criteria of Ornelas et al. (2004) and have a broad correlation in the Jurassic sediments of the coastal plain of the Gulf of Mexico.

• In this work, six microfacies associations (JST-1 to JST-6) were described, highlighting their textural, petrophysical, geochemical, biostratigraphic and diagenetic characteristics from the Tithonian (Upper Jurassic).

• The geochemical and microfacial analysis suggest that the horizons with associations of microfacies JST-2, JST-3 and JST-4, are the most attractive for the exploration and exploitation of “Non-Conventional Reservoirs”

• The indications and results of the wells drilled in this area pose new possibilities for exploration and incorporation of reserves to Petróleos Mexicanos.

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References Granados, H. J., Muñoz, C. R., Caraveo, M. L., Guerrero, T. M., García, O. M., y Padilla, B. R. 2018. El Play Emergente de Aceite No Convencional del Jurásico Superior en México. Boletín de la Asociación Mexicana de Geólogos Petroleros, Vol. LX, No. 1, 7- 28 pp. Ivanova, D. 1997. Upper Jurassic zonation on Cadosinids, Stomiosphaerids and Calpionéllids of the Central Fore Balkan, Bulgaria. Geológica Balcanica. 27, 3-4 p 33.47. 1997. Loeblich, A. R. & Tappan, H. 1988. Foraminiferal Genera and their Classification. Ed. Van Nostrand Reinhold. New York, U.S.A, 970 p. Ornelas, S. M. y Aguilera, F. N. 2004. Integración y Correlación de Eventos del Jurásico Superior- Cretácico en las Cuencas del Golfo de México. IMP, Pub. No.70, 1-135 p. PEMEX- PEP. 2011. Evaluación del Potencial del Play No Convencional de Lutitas Gasíferas del Jurásico Superior Cuenca de Sabinas y Burgo, Informe Inédito. PEMEX – PEP. 2012. Detalle del Play Jurásico Shale Oil-Gas, Informe Inédito. PEMEX – PEP. 2017. Caracterización del Sistema Poroso-Hidrocarburos del Play No Convencional Jurásico Superior Tithoniano Pimienta, Área Anhélido, Informe Inédito.

2.VI Influence of Depositional Sedimentary Record on Diagenesis and Reservoir Quality: Assessment of Preserved Aeolian Norphlet Sandstone (Upper Jurassic) Mexico: Current Understanding and Future Prospects Afsoon Kazerouni, Bemidji State University Mechanical compaction and quartz cementation are among the most important diagenetic controls on the reservoir quality of the aeolian Norphlet sandstone gas reservoir quality (Upper Jurassic) in the Gulf of Mexico (GOM). The magnitude of these two diagenetic events is controlled by the mineralogical composition of the sandstones which consists of rhythmically bedded, thin, calcareous shales, siltstones, and fine sandstones, with thin limestones toward the base. Locally, it shows a period of major clastic influx. Age and thickness of these sedimentary packages vary geographically, assuming that the Sandstones have a common provenance, the nature of the environments in which these sediments were deposited is the principal factor controlling the composition of the framework grains in the unit. Ductile lithic-rich, very fine-grained sandstones featured compaction of easily deformed, clay-rich grains, resulting in a very rapid loss of porosity during burial. In contrast, dissolution and cementation evidences occurred as well as ductile compaction in the fine-grained sandstones. Two episodes of oil charge occurred in the relatively coarser-grained sandstone lithofacies. Diagenesis proceeded alternately with low oil emplacement, and some diagenetic alterations and hydrocarbon charge might occurred simultaneously. This project should encourage drilling activity by focusing exploration on lower risk areas and preventing drilling below reservoir basement. This work can (1) focus deep exploration on areas of thicker lowstand systems tracts, (2) provide methods for forecasting reservoir quality in deep to ultradeep sandstones, and (3) form the basis of later site-specific diagenetic modeling studies where numerical models can be applied. (4) linking the Mexico and U.S. Gulf Coast with eolian sandstone of the Upper Jurassic Norphlet Formation and offshore Alabama (5) predict what factors control the preservation potential of different types of aeolian bedforms and what are the characteristics of the deposits of different bedform types that can be used for effective reconstruction of original bedform morphology.

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SESSION III: GEOCHEMISTRY AND BASIN MODELING 3.I The ‘Missing Source Rocks’ of the Gulf of Mexico Mega-Basin Andrew Pepper (presenter), Andrew Pepper, L. Heister, A. Pradono, M. Moldowan, This is Petroleum Systems LLC Introduction The GoM has ‘missing’ source rocks in two senses: those whose ages are known, but which are absent or poorly developed locally due to non-deposition or erosion; and those whose presence and importance are not yet appreciated. We address known and ‘missing’ source rocks using a predictive global scheme of Jurassic-Paleogene source rock Acmes. An Acme is a time of prominent OM deposition, named with the prefix A and an age in MY (GeoWhen time scale). This evolving database is now calibrated in the GoM, Proto-Caribbean, Atlantic, European, W. Siberian and Middle East basins. Known Acmes have different names from place to place; formations may comprise more than one Acme, especially in basinal condensed sections. We assess each Acme by its Ultimate Expellable Potential (UEP) in mmboe/km2 as well as component oil (UEO) and gas (UEG) potentials. Previous Work Pepper & Yu (1995) documented the importance of a high expulsion potential in promoting vertical migration through thick mudrocks in the GoM. Pepper (2016a-c), This is Petroleum Systems (2016) and Pepper & Pindell (2017) documented the beginning of our ongoing investigations into Mesozoic GoM Acmes and UEP. See Pepper (2016d) for an explanation of the kinetic models that underly the quantitation of expulsion potentials UEP, UEO and UEG. Studies of source rock Acmes and mapping of UEP, UEO, UEG in other global basins were documented by Roller & Pepper (2018), Pepper & Yarbrough (2019) and Pepper et al 2019b,c). In the Gulf of Mexico, Pepper et al, 2017 extended the analysis to the Paleogene while Pepper et al (2020) documented that the often-touted Oceanic Anoxic Event OAE2 actually interrupts two separate Acmes: a strong A95 in the late Cenomanian; and a weaker A93 in the early Turonian, rather than a boundary event at the Cenomanian-Turonian boundary OAE. Norian-mid Bajocian ‘Pre-Salt’ The recently revised, older age for the Louann salt in the Gulf of Mexico (Pindell et al, 2020; and also given at this conference) constrains options for ‘missing’ global Acmes in the thick, unexplored pre-salt (pre-mid Bajocian) stratigraphy offshore Campeche. Triassic-Liassic syn-rift lacustrine source rocks have been proposed, but we find this an unlikely source candidate to support a significant regional petroleum system: being based merely on oil shows in a limited area of the East Texas Basin; based on the arid nature of the basin at this time; and based on global experience of the fickle and discontinuous nature of many syn-rift lacustrine source systems. ‘Top-down’ encouragement for a marine source rock of potentially more continuous regional extent comes from the Early-Mid Jurassic (Toarcian-Bajocian?) Rosario Formation-reservoired oil in well Silozuchil_1001, in the Huayacocotla Basin / Comales Sub-Basin, west of the Tampico-Misantla Basin (Reyes Flores & Rodriguez Cruz, 2016; Rueda-Gaxiola, 2009). We show biomarker evidence for an unequivocally marine origin for this 44OAPI oil and, based on regional analysis, two Acmes are possible for the ‘missing’ source rock. Firstly, using the latest plate reconstruction from Pindell et al (2020) we show that the marine flood depositing the Tethyan ammonite-bearing Sinemurian-early Pliensbachian Huayacocotla Formation came via the Straits of Florida and the present Gulf of

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Mexico Basin, after skirting the Bahamas and Cuba en route from the Atlantic seaway. Pre-Louann salt occurrence in the East Texas Basin can also be interpreted as coeval with this marine flood. Based on the Paris Basin as an analog, this interval correlates with mid-Sinemurian Acme 193. Secondly, the Silozuchil oil resembles Wolfcamp “A” (A278)-sourced oils from the Permian Basin (Pepper et al 2019a), and may have originated in the pre-rift Permian-aged basin that was a southerly extension of the US Permian Basin, underlying much of eastern onshore Mexico. No source potential data are available to us as ‘bottom-up’ support to either origin. Post-salt Callovian- early Oxfordian Acme 161 The Middle East contains an important late Callovian-early Oxfordian Acme 161 that is represented in the Tuwaiq Mountain Formation, source of the world’s largest Petroleum System in the Arabian Basin (Roller and Pepper, 2018), and by the Naokelekan Formation in the Mesopotamian Basin (Pepper et al 2018); the Oxford Clay in the onshore UK represents an equivalent within western European Tethys. In the Gulf of Mexico, this stratigraphic interval occurs at the base of the Smackover Formation or Oxfordian deep water equivalent (Figure 1). In the Smackover-Norphlet petroleum System of the eastern US GoM, organic matter at this potential Acme is ‘missing’ due to destruction by sulfate-reducing bacteria during early diagenesis, resulting in a bench of abundant pyrite (‘Py-Dol’) caused by reaction of H2S with abundant iron from de-watering of the underlying Norphlet red-beds. In Mexico, the flood corresponding to the Acme may be represented by dark mudstones in the upper part of the Callovian Tepexic Formation in the Tampico-Misantla Basin.

Figure1: Callovian to Valanginian portion of a rafted section in the US GoM. This condensed section, often described simply as ‘centered on Tithonian’, is actually an amalgam of at least five separate Acmes. Most importantly, Acme 138 has a significant portion of the total UEP, which is significant because it post-dates the cessation of oceanic spreading at 140MY and should be present throughout the deep water basin

v

Gamma log ex Cunningham && 2015

v

Deep water ‘Tithonian-centered’ condensed section

This Oxfordian-Valanginian interval is the prolific source of most petroleum in the basin: truly ‘world class’• The condensed section comprises at least five individual Acmes: 157, 153, 148, 144 and 138. Additional presence of Acme 161

(‘basal Smackover’) is difficult to prove due to caving in last three cuttings intervals (not shown) entering and inside the salt at TD

• Towards the shelves as sediment supply increases, the separate Acmes split and are more easily identified e.g. A157 is middleSmackover and Santiago; A153 is Haynesville & Taman; A148 is Lower Bossier and Pimienta

• Acmes 144 and 138 were previously not recognized due to exposure and erosion at the 140MY end-drift unconformity on the shelves

138

144

148

153

157

161?

SALT

UEO 64

mmbo

UEG 24

mmboe

Total Oxfordian-Valanginian condensed section UEP 88 mmboe

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Mid Oxfordian-Berriasian Acmes Known GoM Acmes such as the Tithonian-Berriasian (A144), intra-Tithonian (A148), intra-Kimmeridgian (A153), and intra-Oxfordian (A158) span the time of oceanic crust formation (Figure 1) and are missing by excision due to oceanic spreading, progressively from the basin-center spreading ridge to the outboard edge of autochthonous salt. This imparts a ‘missing’ Source Potential risk to the offshore Tampico-Misantla Basin. Valanginian to early Cenomanian (pre-MCU) Acmes The risk of excised Acmes older than 140MY may be mitigated by a series of ‘missing’ (i.e. presently un- / under-appreciated) deep water Acmes post-dating spreading, from Valanginian (A138) to late Albian (A101) and early Cenomanian (A99). Most of these Cretaceous Acmes are ‘missing’ from shelves due to the end-of spreading unconformity (A138) or unfavorably shallow water depths (Pepper, 2016a-c; This is Petroleum Systems, 2016; and Pepper & Pindell, 2017). Mid Cenomanian (post MCU) Cretaceous Acmes In contrast, Cenomanian and younger late Cretaceous Acmes are mainly shelf events in terms of their UEP, UEO and UEG. We show the first published outcrop-to-basin-center UEP maps for A95 and A93 (Pepper et al, 2020). Highest potentials are developed in intra-shelf settings with low clastic/clay dilution, most notably the Maverick Basin in SW Texas, with relatively low potentials in the basin center and in clay-rich shelf settings that experienced clastic dilution. Cenozoic Acmes Paleocene-Eocene source rocks documented in the Wilcox and Claiborne Groups in the US Gulf Coast have poor petroleum potential due to deposition in nearshore environments with oxidized marine and/or transported terrigenous organic input; however produced liquids generally accepted as ‘Wilcox’ oils lack significant terrigenous organic input, which points to one or more ‘missing’ truly marine source rocks in the Paleogene (Pepper et al, 2017). A well in Hardin County, Texas, encountered one of these candidates, developed in the late Paleocene ‘Big Shale’ interval of the Wilcox Group. Its UEP (and UEO) are impressive; quite different to the marginal organic intervals previously and incorrectly proposed as the origin of Tertiary-sourced GoM liquids. Miocene source rocks are also recognized in southern Mexico, though poorly documented in the literature. Summary This is a snapshot of our progress towards fully documenting all the source rocks, recognizing their true Acme ages and mapping their potentials in this prolific Mega-Basin. Much remains to be learned. In Mexico, the Campeche sub-salt and the offshore Tampico-Misantla Basin areas remain vulnerable to our current gaps in knowledge. References Pepper, A.S. (2016a), Back to the rocks: framework of depositional Acmes in source rocks of the Gulf of Mexico Basin and North Caribbean margin: AAPG International Conference & Exhibition, Cancun, Mexico, September 2016.

Pepper, A. S. (2016b), Back to the rocks: Framework of depositional acmes in source rocks of the Gulf of Mexico Basin and North Caribbean Margin: Gulf Coast Association of Geological Societies Transactions, v. 66, p. 853–858.

Pepper, A.S. (2016c), Implications of early Gulf of Mexico tectonic history for distribution of Upper Jurassic to mid Cretaceous source rocks in deep water exploration areas of the US and Mexico: GCSSEPM Perkins-Rosen Conference, Dec 8-9th 2016, Houston. TX

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Pepper, A. S. (2016d), Explaining it better: the Organofacies scheme in modeling petroleum charge from source rocks. YouTube webinar at the LinkedIn Petroleum System Analysis (PSA) community.

https://www.youtube.com/watch?v=NbkHmNpUeEk

Pepper, A.S. and J. Pindell (2017), Implications of early Gulf of Mexico tectonic history for distribution of Upper Jurassic to mid Cretaceous source rocks in deep water exploration areas of the US and Mexico: AAPG Annual Conference & Exhibition, Houston, TX, April 5th, 2017.

Pepper, A.S. and C. Yarbrough (2019), Source rock organofacies, development and preservation: the basis for a quantitative description of source rock expulsion potential, expelled fluid composition, and properties - in time and space: AAPG Middle East Region GTW, Regional variations in charge systems and the impact on petroleum fluid properties in exploration, Dubai, UAE, 11-13th February, 2019.

Pepper, A.S. and Z. Yu (1995), Influence of an inclined salt sheet on petroleum emplacement in the Pompano field area, offshore Gulf of Mexico Basin: GCSSEPM Foundation 16th Annual Research Conference: Salt, Sediment and Hydrocarbons, December 3-6, 1995.

Pepper, A.S, N. Ahmad, and A. Doebbert (2017), Upper Paleocene–Lower Eocene ‘Wilcox’-sourced petroleum systems of the Gulf of Mexico Basin: A re-evaluation and comparison with the coeval Patala Formation–sourced petroleum system in the Upper Indus Basin, Pakistan: Gulf Coast Association of Geological Societies Transactions, v. 67, p. 481-488.

Pepper A.S., A. Doebbert, J.-M. Laigle and Laure Philippe (2019a), Greater Permian Basin Petroleum Systems - what are we learning in the transition from conventional to unconventional?: AAPG Super Basins – The Permian, Sugarland, TX, January 22nd-24th, 2019.

Pepper, A.S, J.-M. Laigle, L. Philippe & C. Yarbrough (2019b), Origins of fluid compositional variation in Northern Iraq, NE Syria and SE Turkey: AAPG Annual Conference & Exhibition, San Antonio, TX, May 21st, 2019.

Pepper, A.S., E. Roller, J.-M. Laigle, L. Philippe, C. Yarbrough (2019c), Source rocks in time and space: a quantitative description of source rock Organofacies, expulsion potential, expelled fluid composition and properties - with examples from some of the world’s major conventional and unconventional petroleum systems: Hydrocarbons in Space And Time, Geological Society of London Petroleum Group Conference, London, 9-10th April, 2019.

Pepper, A.S., A. Pradono & L. Heister (2020), Cenomanian-Turonian Organic Depositional Acmes 93 and 95 in the Gulf of Mexico: paleobathymetry, thickness, lithofacies, Organofacies and Ultimate Expellable Potentials: GeoGulf 2020 Virtual Research Symposium, 2nd October 2020

Pindell J., D. Villagómez, R. Molina-Garza, R. Graham & B. Weber (2020), A revised synthesis of the rift and drift history of the Gulf of Mexico and surrounding regions in the light of improved age dating of the Middle Jurassic salt: In: Davison, I., Hull, J. N. F. and Pindell, J. (eds) The Basins, Orogens and Evolution of the Southern Gulf of Mexico and Northern Caribbean. Geological Society, London, Special Publications, 504,

Reyes Flores R. & T. Rodriguez Cruz (2016), The Lower-Middle Jurassic: Unconventional Tight Oil Play.

Roller E. and A. Pepper (2018), Estimating the Ultimate Expellable Potential of source rocks: defining “world class” for aquatic Organofacies with examples from the Arabian, West Siberian, Bohai, and Williston Basins: AAPG Search and Discovery Article #11055, posted March 5, 2018, adapted from poster presentation given at 2017 AAPG Annual Convention & Exhibition, Houston, Texas, April 2-5, 2017.

Rueda-Gaxiola, J. (2009), The palynostratigraphy of red-bed and salt units of the Mexican petroleum sub-basins of the Gulf of Mexico: In C. Bartolini & J. R. Roma´n Ramos, eds., Petroleum systems in the southern Gulf of Mexico: AAPG Memoir 90, p. 137 – 154.

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3.II Oil and Gas Resources of the Tampico - Misantla Basin Alfredo E. Guzmán, Mexican Petroleum Company Full development of the Tampico - Misantla basin could provide enough oil and gas to cover all of Mexico´s requirements with plenty left to export and generate income. The basin still holds 122 Bb and 76 Tcf but exploration and extraction in the basin have been abandoned for all practical purposes. After Pemex, discovered the mega reservoirs of the Sureste basin in the late 1970´s - early 1980´s, it focused there all of its efforts neglecting the remaining resources of the Tampico - Misantla. The decision made sense at the time as the newly found fields were highly productive while the Tampico - Misantla basin assets were mature and marginally economic. After 40 years the giant fields of the Sureste have been drained and the oil left is in reservoirs in late stages of production and even though there are large volumes yet to be found these are in either deep, hard to explore reservoirs or offshore where facilities are scarce and expensive, while in the Tampico - Misantla basin 74% of the remnant oil is in proven resource plays of tight oil sandstones and oil shales that have been tested successfully with new technologies that can extract the oil easier, faster and cheaper than in the offshore or in deep seated resources, and with little geologic risk. As an analog, the Permian basin today produces 4.2 MMbod and 16 Bcfgd, from depleted carbonates, tight sandstones and oil shales, the same type of reservoirs of the Tampico - Misantla, both with similar OOIP. Extraction of the oil requires EOR for the carbonate fields and horizontal multifractured wells for the tight oil sands and oil shales. México should focus Pemex´s investments in the offshore and deep onshore fields of the Sureste and allow private companies to develop the Tampico - Misantla basin.. 3.III New Exploration Play Concepts in the Tampico-Misantla Basin, from an Understanding of its Thermal Burial History and Source Rock Maturation Mark Shann (presenter), K. Vazquez Reyes, M.B. Canchola, Geomarcas SRL and Wintershall DEA The Tampico-Misantla Basin has had a long and successful exploration history since its first well was drilled in 1866. It lies along the transform margin to the Gulf of Mexico (GoM) to its east, and in a foreland basin setting to the “Sierra Madre fold and thrust belt” to its west and as such the basin has undergone a Late Cenozoic period of isostatic uplift and substantial erosion. This has implications on the thermal maturation history of the basin, and this paper demonstrates a method to restore the likely thickness of sediments eroded, based on AFTA measurements. This paper includes a discussion of the tectonostratigraphic history of the basin, its principal source rocks and their maturation history including paleoburial and the consequent fit to a number of critical oilfield observations in support of a west to east oil charge model in the Early Cenozoic. This is in contrast to the idea that the oil charge is derived from the GoM. In the 1920’s the Golden Lane oil field trend was mis-interpreted as a large structural anticline. Does there remain today other mis-interpreted trends that can lead to new ideas, new play concepts to re-ignite an exploration future for this basin. 3.IV Environmental Drivers of Organic Matter Deposition into the Pimienta Formation During the Jurassic–Cretaceous Transition in Central-Eastern Mexico Mario Martínez-Yáñez (presenter), SEPI-ESIA Unidad Ticoman, Instituto Politécnico Nacional; F. Núñez-Useche, Instituto de Geología, Universidad Nacional Autónoma de México During the Mesozoic, deposition of Laminated Organic-rich Mudrocks (LOM) was commonly linked to exceptional episodes of accelerated global change (e.g. Ocean Anoxic Events) caused by

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profound alterations in the ocean-lithosphere-atmosphere system. However, LOM successions were also deposited in the Proto-Gulf of Mexico during the Jurassic–Cretaceous transition, a time interval of apparent global stability. In particular, the Pimienta Formation is a LOM succession accumulated in central-eastern Mexico and is one of the major hydrocarbon source rocks in the country. In this study, sedimentological, petrographic, mineralogical and geochemical analyses are integrated in order to reconstruct the environmental drivers that favored the deposition of organic matter in this unit. The Pimienta Formation, in the studied outcrop (184-m-thick), is a calcareous LOM characterized by laminated dark-gray limestone (wackestone-packstone), black calcareous shale and reddish layers of bentonite. This unit was deposited during middle Tithonian-early Berriasian under oxygen-depleted bottom water conditions and high shallow marine productivity, in an unrestricted marine setting. These oceanographic conditions were the major drivers that allowed the conservation and burial of large amounts of organic matter. In this regard, the organic carbon-richest levels (0.5-3.9 TOC%) in this unit (lower and middle members) are associated mainly with radiolarian-dominated microfacies, as well as with a high spectral concentration of U. The evidence suggests that those conditions were favored by the supply of volcanic material into mass water. However, the influence of hydrothermal activity from the mid-ocean-ridge linked to the opening of the Gulf of Mexico is not ruled out. 3.V The Southern Gulf of Mexico: A Natural Laboratory of Petroleum Formation Demetrio Santamaría-Orozco, Univerisdad Nacional Autónoma de México – Spanish Presentation Abstract The southern Gulf of Mexico is the most prolific hydrocarbon region in Mexico. That is where the Sonda de Campeche is located. The Upper Jurassic source rocks in this area are mostly black calcareous shales and dark gray clayey limestones deposited in an anoxic environmental, with thicknesses greater than 300 ft, and values from 2% to 22% total organic carbon (TOC). Type II-S kerogen and AB organofacies. The maturity covers the whole oil window, and so the sequence ranges from immature to overmature from NE to SW direction with values from 0.4 to 1.3% of vitrinite reflectance (Ro). Crude oils from all reservoirs in the area varies from extra-heavy to super-light in the same direction of the maturity and its range cover from 10 to 45 API gravity, which indicates a supercharged, vertically drained, high impedance petroleum system. Most of the reservoirs are in naturally fractured carbonate rocks of the Upper Cretaceous, although there are some good reservoirs in rocks from the Kimmeridgian and Paleocene ages. The close correlation shown by biomarker analysis from source rock extracts with stored oils indicates that the oil precursor was Jurassic organic matter (mainly Tithonian and less Oxfordian). The extra heavy NE oils have high Sulfur content, and despite their high viscosity, none showed biodegradation. Based on this relationship, a sample of kerogen, the most immature, was used to artificially simulate the thermal evolution, to determine the composition of the products generated. This was done, to establish the quantity of hydrocarbons generated and expelled during a programmed temperature increase. The mass balance served to compare the natural vs. artificial series. The results indicated that the gas-oil ratio (GOR) obtained in the laboratory fits very well with the GOR measured at the wellhead in most of the reservoirs. In this Tithonian sequence, new molecular parameters of maturity have been proposed based on sulfur and nitrogen compounds, as well as temperatures of petroleum formation based on asphaltenes, for both crude oils and source rock extracts. Also, there has been made good predictions of fluid properties such as formation volume factors, saturation pressure and other geochemical data for reservoir evaluation. The kinetic parameters of the natural sequence of source rocks were determined to establish a generation model used to calibrate the basin modeling of the Southern Gulf of Mexico, finding that the petroleum generation begins at 0.45 %Ro. Finally, this region was compared with other similar ones in the

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world, concluding that even though they have things in common, they are far from being the same, for example, the Mesopotamian Basin in Iraq, the Western Canada Basin, the Maverick Basin in the USA which have naturally matured source rocks and crude oils derived from these rocks, but none have the wide variety of petroleum from extra heavy to super light. Also, another region that is very interesting, is the Hils Sincline northern Germany, although in this region there is not oil nor gas production. References Clara Valdes, M. de L., Villanueva Rodriguez, L. and Caballero Garcia, E., 2009, Geochemical integration and interpretation of source rocks, oils, and natural gases in southeastern Mexico, in C. Bartolini, and J. R. Roman Ramos, eds., Petroleum systems in the southern Gulf of Mexico: AAPG Memoir 90, Chapter 16, p. 337–368.

Clegg, H., Wilkes H., Oldenburg T., Santamaría-Orozco, D. and Horsfield B., 1998. Influence of Maturity on Carbazole distribution in Crude Oils and Source Rocks from the Sonda de Campeche, Mexico. Org. Geochem. v. 29, Nos. 1-2. pp. 183-194.

Creaney, S., Allan, J., Cole, K.S., Fowler, M.G., Osadetz, K.G., Macqueen, R.W., Snowdon, L.R., Riediger, C.L., 1994. Petroleum generation and migration in the Western Canada sedimentary basin, Geological atlas of the Western Canada sedimentary basin. Canadian Society of Petroleum Geologists, Calgary, AB, Canada | Alberta Research Council Edmonton, AB.

EIA, 2014, Updates to the EIA Eagle Ford Play Maps, pp. 10.

di Primio, R. Horsfield B. and Guzmán–Vega, M. A., 2000, Determining the temperature of petroleum formation from the kinetic properties of petroleum asphaltenes. Nature, v. 406, No. 6792, p. 173-176.

di Primio R. and Horsfield B., (2006) From petroleum-type organofacies to hydrocarbon phase prediction, AAPG Bulletin, v. 90 no. 7, p. 1031–1058.

Guzmán-Vega, M., and Mello, M. R., 1999. Origin of oil in the Sureste Basin, México: AAPG Bulletin, v. 83, p. 1068–1095.

Hakimi, M. H., Najaf, A. A., Abdula R. A., Mohialdeen M. J. I, 2017. Generation and expulsion history of oil-source rock (Middle Jurassic Sargelu Formation) in the Kurdistan of north Iraq, Zagros folded belt: Implications from 1D basin modeling study, Journal of Petroleum Science and Engineering v. XXX, p. 1–21.

Horsfield, B., U. Disko, and F. Leistner, 1989, The micro-scale simulation of maturation: Outline of a new technique and its potential applications: Geologische Rundschau, v. 78, p. 361–374.

Kenning, J. J. and Mann P. 2020, Control of structural style by large, Paleogene, mass transport deposits in the Mexican Ridges fold-belt and Salina del Bravo, western Gulf of Mexico, Marine and Petroleum Geology, v. 115, No. 5, (accepted).

Magoon, L. B., T. L. Hudson, and H. E. Cook, 2001, Pimienta-Tamabra(!)—A giant supercharged petroleum system in the southern Gulf of Mexico, onshore and offshore Mexico, in C. Bartolini, R. T. Buffler, and A. Cantú-Chapa, eds., The western Gulf of Mexico Basin: Tectonics, sedimentary basins, and petroleum systems: AAPG Memoir 75, Chapter 4, p. 83-125.

Rahman, M. W., Hull D., Chapman P. and Riggs G., 2017. Organic Facies and Reservoir Characterization of Eagle Ford Shale as Determined by Stratigraphy, Source Rocks, and Oil Geochemistry. AAPG. Search and Discovery Article #10939.

Rullkötter, J., D. Leythaeuser, B. Horsfield, R. Littke, U. Mann, P. J. Muller, M. Radke et al., 1988, Organic matter maturation under the influence of a deep intrusive heat source: A natural experiment for quantitation of hydrocarbon generation and expulsion from a petroleum source rock (Toarcian shale, northern Germany): Organic Geochemistry, v. 13, no. 4–6, p. 847–856,

Santamaría-Orozco, D, 2000. Organic Geochemistry of Tithonian Source Rocks and Associated Oils from the Sonda de Campeche Mexico 168 p.: ISSN 0944-2952 Ed. Forschungszentrum Jülich, Germany.

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Santamaría-Orozco, D, di Primio, R, Pickel, W., Hoguín, N., Horsfield B., 1995. Organic facies and maturity of Tithonian source rocks from the Sonda de Campeche, Mexico, Organic Geochemistry, Development and Applications to Energy, Climate, Environment and Human History, 17th International Meeting of Organic Goechemistry, EGOA, San Sebastián España. Abstracts p.152-154.

Santamaría-Orozco, D. and Horsfield B., 2003. Gas generation potential of Upper Jurassic (Tithonian) source rocks in the Sonda de Campeche, Mexico, in AAPG Memoir 79, Chapter 15, p. 156-163. ISBN 0-89181-360-8, Ed. By Bartolini C, Buffler, C. y Cantu C. A.

Santamaría-Orozco, D. and Horsfield B., 2010. Predicción de la Calidad de los Aceites en la Sonda de Campeche, México, Boletín de la AMGP, v. 55, No. 1, p. 22-39.

Santamaría-Orozco, D., di Primio, Horsfield B., and Welte D. 1998. Influence of maturity on of benzo- and dibenzothiophenes in Tithonian source rocks and crude oils, Sonda de Campeche Mexico. Org. Geochem. V.28, Nos. 7-8, pp. 423-439.

Schaefer, R.G.; Schenk, H.J.; Hardelauf, H., y Harms, R., 1990. Determination of Gross Kinetic Parameters for Petroleum Formation from Jurassic Source Rocks of Different Maturity Levels by Means of Laboratory Experiments. In Advances in Organic Geochemistry 1989. Organic Geochemistry, v. 16, n. 1-3.

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SESSION IV: GEOPHYSICS AND RESERVOIR CHARACTERIZATION 4.I From Data to Discovery in the Gulf of Mexico South: New Methods for Digital and Subsurface Integration Marco Antonio Arreguin, Western Geco Mexico, Central America and the Caribbean No abstract provided

4.II Results of the Application of Rock Physics in Unconventional Resources Hugo Avalos Torres (presenter), L. Velasquez-Contreras, M.A. Porras Vazquez, O. Fabela-Rodriguez, Petróleos Mexicanos (PEMEX) – Spanish Presentation Introduction The emergence of unconventional reservoirs (UR) has transformed the perspective of the exploration and development of in the hydrocarbons world. The UR defined by its low permeability and porosity, are gaining importance in the exploration and production of hydrocarbons in Mexico. The complexity presented by the UR requires the application of new technologies and workflows helping to reduce the uncertainty in physical and geological mechanisms, one of these is the rock physics method. Antecedent Traditionally, the rock physics method has been applied to conventional sandstone formations and in lesser degree to carbonate formations (limestone and dolomite). In this work was applicated in UR of shale oil & gas. Objective The main task is predict elastic and petrophysical properties in UR, know the role that these properties play in hydrocarbon forecasting, and provide one more input in seismic inversion techniques to support hydrocarbon exploration and production. Method / procedure Workflow activities included: researching and collecting information about UR; rock physics flow learning and application; conduct a feasibility analysis; elaboration of crossplots; construction of a mineralogical modeling derived from petrophysical evaluation and application of rock physics method. The results are part of the inputs to carry out some special seismic processes and seismic inversion.

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Figure 1. Generalized workflow sequence to conduct rock physics. Results The initial feasibility analysis of impedances P vs S, combined with petrophysical properties, shows a clear identification or discrimination between pure carbonates and a UR, this is a simple determination when impedance changes also lithology does. The initial feasibility analysis of P impedance and S impedance, combined with petrophysical properties, shows a clear identification or discrimination between pure carbonates and a UR, this is a simple determination when impedance changes are related to lithology. It is clearly observed how the cloud of values inside the polygon hatched in blue, has its representation (or projection) in the graph of registers on the left. This answer is unique and exclusive to the horizon that represents a UR. With this, it can be interpreted that there is a relation between rock properties and elastic properties; therefore, is possible that there is a relationship of the rock with some seismic reflectors, or with the seismic itself. Furthermore, it is observed that: a)- As the TOC increases, the impedances (P and S) decrease, that is, the elastic properties tend to decrease. b)- If the impedances (P and S) tend to decrease, the brittleness (BRITT) also decreases, in this document, for the reservoir area, the ranges observed of for britt were 35 to 60, while for TOC were + 1 to 5% Wt). c)- Regarding porosity, if the impedances (P and S) decrease, the porosity increases and vice versa; if the impedances (P and S) tend to be high the porosity decreases. d)- Regarding the volume of clay (VCL), when the impedances (P and S) decrease, it tends to increase, and vice versa; when the impedances (P and S) tend to be high the VCL decreases.

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According to Zhiqi Guo., et al (2013); Kulyaping and Sokolova (2014), the results show that the seismic attributes of Vp/Vs and Impedances P, can reflect a variation in porosity (PHIE), and more sensitivity in the variation of clay content (VCL), especially as which increases the PHIE. The results obtained establish that it is possible to find a relationship between petrophysical and elastic properties, if so, then it is possible to find a relationship between rock and seismic. Therefore, if this relationship exists, more precise information can be obtained to support exploration opportunities and locations, thus supporting the determination of specific areas, intervals and horizons to drill a pilot well, direct a horizontal well, and support the determination of stages of fracturing during completion.

Figure 2. Crossplots of PIMPMOD vs SIMPMOD, with petrophysical properties (TOC, BRIT, PHIE, SW

and VCL).

Conclusions

• The quality of data (original and analog) is critical; This guarantee the quality of the results.

• The feasibility analysis of impedances P vs S, combined with petrophysical results shows good identification in a UR (shale oil), therefore, the data are suitable for the application of rock physics.

• The analysis carried out with crossplots of modeled impedances P and S vs petrophysical properties establishes that there is a relationship between formation and seismic in a UR.

• Establishing a relationship between rock properties and seismic data, more precise information is obtained to determine better horizons and areas (or sweet spot).

• This kind of analysis supports the definition of the drilling of a pilot well, directing a horizontal well, and determining fracturing stages during its completion.

• The results of rock physics are part of the input required in the techniques of special seismic processes and seismic inversion, which serve to support exploration opportunities and locations, even where there are no wells and only seismic data exists.

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Acknowledgements To PEMEX Exploration and Production, for the facilities granted to publish this document. References Avalos-Torres H., et al. 2018. Análisis mineralógico y características petrofísicas en YNC. Boletín de la AMGP. Vol. LX. Num. 1, pp. 29-48.

Méndez-de León., J., 2014. Metodología de análisis petrofísico para un yacimiento no convencional (YNC) tipo shale gas/oil (articulo), en Congreso Mexicano del petróleo, Acapulco, Gro., México., pp. 20.

Pavel Kulyapin and Tatiana F. Sokolova. 2014. A case study formation evaluation and physics modeling of the Bazhenov shale. (paper) PETROPHYSICS, Vol. 55, No. 3 (June; page 211-218).

Tepper B., et al. 2013. Petrophysical evaluation of shale oil / gas opportunities in emerging play; some examples and learning's from the Americas. (paper) in International Petroleum Technology conference (IPTC 16926), Beijing, China, pp. 7.

Vargas-Meleza L. y Valle-Molina C. 2012. Avances y aplicaciones en física de rocas para exploración de hcs. Ingeniería, Investigación y Tecnología. Vol. XIII. No. 4. Pp. 439-450. ISSN 1405-7743 FI-UNAM.

Xuan Qin., et al. 2014. Rock physic modeling of organic-rich shales with different maturity levels. in 2014 SEG Annual Meeting, Denver, Co. DOI: http://dx.doi.org/10.1190/segam2014-1584.1. Pp. 2952-2957.

Ying Li., et al. 2015. A rock physics model for the characterization of organic-rich shale from elastic properties. Springer. Springerlink.com. DOI 10.1007/s12182-015-0029-6. CrossMark. Original paper. Vol. 12, pp. 265-272.

Zhiqi Guo, et al. 2013. A shale rock physics model for analysis of brittleness index, mineralogy and porosity in the Barnett Shale. Journal of Geophysics and Engineering. Vol. 10. http://dx.doi.org/10.1088/1742-2132/10/2/025006.

Zhongping Li., et al. 2014. Shale-gas reservoir-prediction study in Daanzhai, eastern Sichuan basin. The Leading Edge. Especial Section: Reservoir Description. pp. 526-532.

4.III Lithology’s Petroelastic Characterization of the Eagle Ford Group by Using Modern Rock Physics Templates Rubén Nicolás-López (presenter), J. M. Espinosa-Ortega, J.A. España-Pinto, O.C. Valdiviezo-Mijangos, Instituto Mexicano del Petróleo A petroelastic characterization applied on the Eagle Ford Group, located in the Burgos basin, is carried out by using Rock Physics Templates RPTs, which are computed with a micromechanical model based on the effective elastic properties of mixtures of calcite, quartz, clay and pore-filling fluids. The novel proposed workflow includes criteria stemmed from GR, RES, RHOB, DTCO, DTSH logs, TOC and Vp/Vs ratio curves. The elastic responses of the formations are qualified by ranges of the rock’s elastic moduli; here lambda-rho and mu-rho are used. Petroelastic characterization is carried out by relating the rock’s elastic moduli with the zones of RPTs. The elastic responses tending toward the calcite vertex are interpreted like calcareous lithotypes, data tending to the clay vertex are called argillaceous lithotypes, and those which tend to the quartz vertex are grouped as siliceous lithotypes. Lithology and reservoir identification from RPTs are the most important outcomes. At lower member of Eagle Ford/Agua Nueva, the reservoir is targeted in the base and the top is dominated by siltstone and clayely limestone. The upper Eagle Ford/Agua Nueva zone is composed by clayely limestone and flaggy limestone. Lower section of San Felipe is an interlayered formation composed of thinly beds of clayely limestone, limestone and marls; upper section is dominated by marls. San Miguel/Parras is mainly composed of a rich-clay mudstone. Results are related to brittleness indices to enrich the idea of shale-gas-oil exploitation

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is attainable without fracking. They can be also scaled to inversion seismic data to improve previous static reservoir characterization. 4.IV Qualitative Interpretation of Potential Methods in the Terrestrial Portion of the Geological Province of the Yucatan Platform: the Extension to Mexico of the Sedimentary Basins of Corozal (Belize) and Petén (Guatemala) Edilberto R. Hernández Flores, Independent Consultant– Spanish Presentation The objective of this work is to determine the extension to Mexico of the Corozal and Petén basins, through the qualitative interpretation of the Residual Gravimetric Anomaly and Reduced Pole Magnetic Anomaly maps. The Yucatán cortical block in its marine portion is important because it contains giant oil fields, in its land portion, Mexico has drilled 23 exploratory wells without establishing oil production, in Belize two fields of the Corozal basin, located near the state of Quintana Roo, they produce 5,000 barrels per day, in Guatemala, 8 oil fields produce 10,000 barrels per day, 3 of them are located near the border with the state of Chiapas Mexico. The Petroleum evaluation of the Yucatán platform, carried out in 2012 by the USGS, reports that the undiscovered reserves of the SE of the Yucatán Platform could have an average of 440 MMBO and 1,036 BCF for the Cenozoic-Mesozoic, and for the basins of the Fold belt of the Sierra de Chiapas and Petén, the undiscovered reserves could be 993 MMBO and 753 BCF (Table 1).

Table 1. Assesment results for undeiscovered conventional oil and gas resources for provinces of Mexico, Guatemal and Belize, USGS 2012.

The combination of the Bouguer Anomaly and Magnetic Anomaly maps and their residues are used in Oil Exploration to interpret regional structures such as: faults, buried fold belts, saline structures and clay structures, and basin geometries and sedimentary platforms. The interpretation of the geometry of the Veracruz basin is shown as an example, where an alignment of gravimetric minima is associated with the thickness of the Tertiary terrigens Figure 1.

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Figure 1 Gravity expression of the Veracruz basin

The methodology used in this work was the analysis and processing of the gravimetry data INEGI 2010 (Figure 2 b) and the magnetic data of the USGS (2002) of the magnetic chart of N.A. (Figure 2 a).

Figure 2. a) Magnetic data of the study área, obtained of the North America Magnetic; Chart b)

Gravity data obtained of the INEGI, México 2010.

Spatial signals like the Bouguer Anomaly contain two components, one regional and the other residual. The Bouguer Anomaly is generally present, and its components are unknown. To obtain the map of the residual gravimetric anomaly, it is required to know the map of the regional anomaly. This map was obtained from the low-pass filtering of the Bouguer Anomaly. The residual gravimetric Anomaly map used in this work was obtained from the difference of the Bouguer Anomaly map minus the Regional Anomaly map. In Belize, the Corozal basin is associated with a gravimetric minimum with an almost North-South orientation, its extension to Mexico could be 5,423 km2. It has been named Cuenca de Quintana Roo( Figure 3a). The Peten Norte basin is associated with a gravimetric minimum with an area of 490 km2 where the Xan field (largest producer of light oil) was drilled. In Mexico, an alignment of gravimetric minima is observed that extends through the state of Campeche with an area of 10,733 km2. This basin has been named the Campeche basin (Figure 3b). For the basins of the Sierra Madre de Chiapas and Peten Sur belt, an alignment of gravimetric minima is observed. This alignment begins in Guatemala and continues towards Mexico following

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the convex geometry of the Chiapas outcropping. The basin associated with this alignment has an area of 12,686km2 (Figure 3c). From the results obtained, the usefulness of the gravimetry and magnetometry data for the interpretation of the Corozal and Peten basins is concluded. As well as three posible sedimentary basins in Mexico with an explorable area of 28,842 km2. Other interesting structures interpreted from the residual gravimetric anomaly map are the meteorite Chicxulub impact structure at the Cretaceous / Tertiary boundary and the Liberty Arch.

Figure 3 The sedimentary basins a) Sierra de Chiapas Fold Belt, b) Campeche and c) Quintana Roo. The Potential Methods analyzed, processed and interpreted in the Yucatan Platform have shown their usefulness in the selection of areas of economic-oil interest. In this work the continuation of

the Corozal Basins, Petén Norte was interpreted. The verification of the extension to Mexico of these producing basins in Guatemala offers the opportunity to manage them as transboundary oil

reservoirs. An alignment of gravimetric maxima associated with the Arco de la Libertad with NW-SE direction was interpreted, which extends from the coastline of the state of Campeche to the Maya Mountains. The gravimetric and magnetic expression of the Chicxulub crater was also interpreted It is recommended to acquire Partial Tensor Gradiometry, regional 2D seismic. From the seismic interpretation, construct balanced and restored structural sections that will be modeled with gravimetry and magnetometry to obtain a map of the crystalline basement. Also, it is recommended to reactivate the Mexico-Guatemala technical cooperation treaties to share Geophysical-Geological information and develop possible Transboundary Reservoirs.

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4.V Methodology for Regional Velocity Models Using 2D and 3D Data for Depth Conversion Moises Huicochea Campos, Schlumberger (presenter); F. Rocha Legorreta, Instituto Mexicano del Petróleo; D. M. Tellez Castro, Universidad Central de Venezuela, S. R. Mata Garcia, Schlumberger Summary One of the most important challenges facing inside the Oil and Gas industry is to create regional exploration velocity models for depth conversion mixing velocities from different sources (Wells, 2D & 3D velocities), to evaluate correctly available resources. Thinking logically, the normal way is to have all the velocities in the model interpreted with the same criteria and also from the same seismic processing. Although this is true, deadlines and budgets do not make it possible in all cases. As a consequence, it is necessary to apply methodologies that include different seismic velocities which can be calibrated with wells to be able to solve this issue, considering geological conditions. The methodology proposed is based on the geological understanding to work with 2D and 3D velocities in the same 3D geological model. Once velocity is considered as a geological property using interval velocity value, this is scale-up using wells, 2D and 3D into a structural framework to define zones with similar behavior in terms of velocity values, then it is time to use Geostatistics to analyze and extrapolate inside the area of interest, using wells and structural seismic interpretation to build a correct 3D velocity model. The aim is to lower uncertainties associated with vertical and horizontal structural contexts. A 3D model is represented by zones that reflect geological variations showing as velocity changes, and test different resolution scenarios to evaluate uncertainty related to the geometry of the model. To conclude, the use of velocities as a geological property ensures obtaining a confident regional velocity model for depth conversion, facing successfully the challenge to combine velocities coming from Wells, 2D, and 3D seismic. Introduction The area of interest in this regional velocity model is part of GOM and it is extended in 50,000 km². Twelve different geological units were considered by the same number of horizons including 2D & 3D interpretation, velocity data, as well as three calibration wells all together represented in a 3D Model using almost 150,000 cells. Velocity model construction faced different challenges due to the scale of work, several sources of velocity data, different criteria from seismic interpreters and, limited computer resources. Results were used for time to depth conversion in regional exploration analysis for resource assessment and prospect identification. This works begins by highlighting the importance of QC data in this kind of projects where it is necessary to analyze all the information used in the model, doing QC in three steps: visual, graphical, and numerical to identified positively anomalous data and prepare all the information that was included in the model. One key task was joining 2D and 3D seismic velocity information, after analyzing different scenarios a decision was made to do it using interval velocities corrected with wells information in a 3D model represented by cells. Considering geological character reflected by this type of velocities and using a correction factor to put it on the same scale and use the power of Geostatistics to populated across all the areas of interest.

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Using wells calibrated data in the area helps to lower uncertainties associated with vertical and horizontal structural heterogeneities. Then, building a 3D model considering geological variations as velocity changes improves the potential evaluation process for prospect and plays in the area. Data quality control and conditioning The quality control and conditioning of the input data to the velocity model is a task that should not be underestimated since a good quality of the information depends on obtaining a good model. This first point is the most time-consuming in the construction of the velocity model. In the work carried out, the time invested in the quality control and conditioning of the information was 50% of the total effort in time dedicated to the construction of the velocity model dedicated to the conversion of time to depth domain. In the exploration scale, not only are different 2D and 3D velocities used for the construction of the models, as well as seismic interpretation of different interpreters’ criteria. This methodology begins with the description of the information necessary for the construction of the velocity models used for the conversion of the time to depth domain and the requirements that this information must meet to be useful in successful modeling. We organized input information into 3 categories:

A. Grouped in an organized way all the data that indicate the velocity values within the area of interest of the model (AOI) including: o Well velocities (VSP, Checkshot, or Time Depth Relations) o Well logs (Sonic logs) o 2D & 3D seismic velocities

B. Geological and structural model associated information o Horizons and faults interpreted o Wellheads o Well survey information o Regular surfaces from seismic interpretation using geological criteria

C. Information used for the correction and calibration of the velocity model o Geological Well Tops

Detailing each task performed for QC A. Velocity information in AOI: The quality control of the velocity data begins with the most reliable reference of velocity in the Well, in the work carried out is Wells with VSP, Checkshot, or the sonic record converted to velocity using a simple rule of transformation of units shown in equation 1.

Equation 1. Velocities obtained from Sonic well logs

QC of Velocity data was executed in three different ways:

• Visual QC. Obtaining the interval velocity information from time to depth relationship (TDR) as well log and checking that the Well displayed in the time domain space occupies a reasonable position on the vertical scale or without deforming on the horizontal scale, as shown in Figure 1.

Vp (m/s) = 304800/ (DTC → s/ft)

Vp (ft/s) = 10^6 / Sonic (DTC → s/ft)

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Figure 1. Visual QC of TDR represented as Interval velocity well log data

• Graphical. Quality control supported by cross plots using the well interval velocities and a depth index (Z or TWT), this looking for values outside the geological trend of the velocity values for each sequence (figure 2) and checking that all the values are geologically possible (Schultz, 1998) according to the geological formations in the area of the model. Table 1 shows the velocity ranges by rock type for the study area. During the development of the methodology, when anomalous Well velocities were found, they were corrected (using trends or eliminated), only in the case that there are few anomalous points so that a correct trend of the velocities can be established for each defined geological zone.

• Numerical. Finally, regarding the Well velocity data, it must be reviewed numerically (Table 2), where the values of Interval velocities in the Wells must be seen to be within the geological range possible for the rocks within the area of interest (AOI) of the model, in addition to the generation of histograms (figure 2).

Figure 2. Histogram with interval velocity distribution from wells

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• Seismic velocities 2D & 3D seismic velocity data were analyzed for quality control and to do so it was necessary represented as interval velocities. In the case of 2D velocities coming from RMS processing, it was necessary to apply the Dix equation and transform them into interval velocities (Schlumberger, 2015) to be able to compare with those coming from the Wells. Before doing this step, the anomalous values are identified and adjusted to avoid their incorporation in the interval velocity conditioned data set (figure 3), these values can be eliminated if they are few and interpolated with their correct neighboring values when distributing the velocities within the AOI.

Figure 3. Identification of anomalous values in seismic velocities

B. Geological and structural model associated information The information from Well logs used to associate vertical variations in geology and velocities were: Gamma Rays (GR), Density (RHOB), and interval velocities on Wells from a VSP or from the sonic log to highlight the lithological contrasts associated with velocity changes (figure 4). In this process, the number of correct horizons were defined to represent the changes in velocities inside the model known as control horizons, these are required to have interpreted across all the AOI.

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Because domain conversion requires vertical integration of interval velocities and travel times, control horizons are often represented as interpolated regular surfaces (Figure 5), to have data in all points inside AOI combining 2D and 3D seismic interpretation data to represented as one single element.

Figure 5. Control horizon from 2D & 3D interpretation represented as single continue Surface inside

AOI Additionally, each of the surfaces generated with the seismic interpreted horizons were used for the construction of the structural model and must have the same coverage within the AOI of the model. Otherwise, it could not be considered in the structural model represented by cells to be built for the velocity distribution (figure 6), to extend the coverage in case of missing interpretation geological rules were applied to identify between erosions, unconformities, or conformal surfaces as trends.

Figure 4. Horizon control identification

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Figure 6. Coverage of the surfaces used in the velocity model

In the case of the combinations with 2D and 3D seismic interpretation, it was necessary to correctly identify the sequences that are conformable from the erosive or discontinuous ones. In the construction process of the structural model, continuous surfaces were used within the AOI, avoiding that this present crosses due to the lack of data or problems of interpolation of the interpretation. Regarding the conformable surfaces, trends are used in the interpretation algorithms so that in the areas without information the thicknesses were maintained and crosses between surfaces that represent different levels were avoided (figure 7).

Figure 7. Surfaces Interpolation without trends (Left) and using trends (Right)

Regarding the Well headers and their trajectories, it is advisable to request a base map that geographically confirms their position, as well as the seismic navigation, to perform a quality control concerning their reference. C. Information used for the correction and calibration of the velocity model

The use of geological well tops for the correction and calibration of the velocity model is carried out by associating the horizon interpreted (represented by surfaces) in the seismic with its corresponding event in the Well, following a very simple premise “what does not adjust in the time domain, does not adjust in-depth". The interpretation in the time domain must adjust to the event it represents (figure 8), this in wells that are within the AOI that have a reliable time-depth relationship to be used in the velocity model that is being built.

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Figure 8. Quality control of seismic interpretation vs well tops 3D Structural model represented by cells Building structural modeling implies that seismic horizons and faults are transformed into a geo-cellular 3D model. About the area of interest (AOI), it needs to have the same area extension as the structural model. If there is any geological event such as erosion or truncation, they have covered the area of interest, otherwise, surfaces will be facing errors in the following step. Another important aspect is the order in which the geological time is marked. For instance, seismic horizons have to be set chronologically, starting with a surface of reference. The data using for this model correspond to the Gulf of Mexico (GOM). For this model, the initial surface of reference was the mean sea level (MSL) due to the nature of the data. The bottom of the model is the last surface of reference, which should be placed just after the last seismic horizon of interest (Schlumberger, 2015). The Jurassic horizon is the last level of interest, where it takes place the source rock. This level is a key to explore the rest of the petroleum system elements (figure 9).

Figure 9. 3D Structural Model Extended inside AOI

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Using Geo-statistics allow distribution interval velocities inside the area of interest (AOI). Additionally, 2D and 3D velocities can be handled as a physical or geological property (figure 10).

Figure 10. 3D Structural Model represented by cells

2D & 3D velocity model integration Once the representation of the structural model as cells has been obtained, the interval velocity distribution is made within the entire area of interest according to the following workflow (figure 11):

Figure 11. Workflow for velocity field modeling

In this workflow, the union of the interval velocities stands out, this allows working both velocities on the same geological scale since as average velocities do not present a geological link is not possible to consider this as recommended input for this kind of models. Another important point is

Identification of 2D lines inside AOI

Extract velocities from 2D lines as points

Identify the coverage area of 3D seismic velocities

Scale up 2D & 3D interval velocities to the structural model represented by cells

Leave a blank space between the 2D and 3D seismic velocities to facilitate a smooth transition zone between, considering both as interval velocities adjusted with wells

Make a distribution using 3D and 2D velocities, to have them as a continuous 3D property within the AOI, using moving avarage as algorithm ang geological trends

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to leave enough space between both types of velocities for a smooth transition, then covered it with the use of Geostatistics looking for continued velocities following geological trends in the area. The interval velocity distribution using Geostatistics for interpolation of these in the AOI using the limits of the 3D structural model both vertically and horizontally, in this way the interval velocities can only take values between the maximum and minimum defined in each of the layers in the 3D model. Structural changes must coincide with the geological velocity changes of the control horizons for an accurate model. If the present scenario shows a large variation between both velocities (2D and 3D), these should be joined after adjusting both independently with the Well values to reduce the difference between them and can work it as a single model. Velocity correction For the correction of the velocity field, the interval velocities in the Well are taken as reference, considered in the methodology as the correct velocity value. In this scenario, the equation described by Marcos Victoria (Victoria, 2007) was used, in which he establishes that the Well velocities can be equal to the seismic if they are multiplied by an anisotropy factor defined as AF (Equation. 2).

Equation 2. Calculation of the anisotropy factor

If the seismic interval velocities fit perfectly with those coming from Wells, the expected value of AF = 1, which is not normally fulfilled; therefore, there is a difference between the two dues to their nature (figure 12). A comparison can be made by extracting the seismic velocities along the trajectory of the Wells and populate using 3D structural model limits to create a correction volume for intervals seismic velocities.

Figure 12. Representation of the anisotropy factor in the AOI The acceptable AF value was considered if it is less than 20% of the difference between the Well velocities and the seismic ones, that is, AF should take values between 0.8 and 1.2 (Victoria, 2017). If it presented values outside this range, then it will not be possible to correct the seismic velocities with those of the Well (figure 13). Normally this happens in zones with velocity inversions or in transition zones between siliciclastics and carbonates, where the velocity difference between the two is very large when the processing velocities correspond to RMS and not to the interval.

AF= Well velocity / Seismic velocity

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The correction of the seismic velocities was carried out by solving equation 2, establishing that the seismic velocities multiplied by the anisotropy factor (AF) are equal to those coming from wells, thus leaving corrected seismic velocities (Equation 3) in the total extension of the model.

Equation 3. Corrected seismic velocities By multiplying the seismic velocities by the anisotropy factor in each of the layers of the velocity model, the correction of the seismic velocities was executed, achieving an adjustment along the column where there is information from the Well (figure 13). It is good to remember that the resolution of the Well data (centimeters) is being compared with the seismic resolution (tens of meters), this correction was previously proposed less than 20% before applying it.

Figure 13. Corrected seismic velocities

The anisotropy factor was extended along the entire vertical column of the constructed 3D model, considering in the lower part of the model a linear regression of the curve that represents the anisotropy factor to assign a correction value to seismic velocities below the well data. It should be noted that in the Gulf of Mexico models this has given good results in the scenario where the Wells only reaches a part of the area to be corrected and the correction was extrapolated. However, when there is no Well information in the area, this extrapolation is carried out avoiding that values of the corrected seismic velocities are outside the geologically possible values. The value of the anisotropy factor must be distributed throughout the entire area of interest; therefore, it is possible to guide its distribution with the same seismic velocities already distributed and thus, be able to obtain the corrected seismic velocities within the model area.

Corrected seismic velocities = AF x Seismic velocities

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Depth conversion results using model In previous stages, seismic velocities were corrected and distributed in the AOI. Moving on to how depth conversion works in practice, a minimum adjustment to the well markers is needed to transform seismic horizons to homogenous surfaces (Schlumberger, 2015). By and large, it is common to adjust some meters because of the seismic vertical resolution. For Exploration models focusing on Petroleum System, the last stage can be omitted due to minimum variations. However, if the purpose of the model corresponds to prospects generation, it is recommended to apply this adjustment expecting lower uncertainty in volumetric estimation. Then, the next stage is about transforming the seismic velocity model into a seismic interval velocity cube in SEGY format (figure 14). Having the model in SEGY format grants the compatibility of use in any platform of interpretation (Carter, 1993). Then, it can be used to depth converter any of the seismic interpretation elements inside the area of interest, as well as In terms of the success of the project, the results have been positive due to you will be able to convert any seismic interpretation element as well as to obtain the time-depth relationship (TDR) inside the area of interest. A Wellbore stability window can also be predicted.

Figura 14. Modelo de Velocidades integrado 2D y 3D, calibrado a los Pozos en el AOI

Conclusions In conclusion, this methodology shows a different way that velocities can be treated. They can be managed as a physical property directly linked to the geology. The success of the project will not depend just on the data, but also on the geological knowledge of the area of interest. If seismic velocity data is the only input data considered, an extrapolation and calibration using wells would not be possible. Consequently, any depth conversion and volumetric estimation for Exploration purposes will not be reached precisely. Understanding the nature of the 2D and 3D seismic velocities is remarkably complex and entailed hard work. Intrinsically, velocities have their essence, implying a wide variety in their use and application for time to depth models.

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Acknowledgments I would like to express my special thanks of gratitude to Carlos Miguel Perez, Lázaro Arvizu (PEMEX) as well as Moises Garcia (CNH) who guide me and helped to have a much better understanding of this methodology in complex scenarios. This project tackles difficulties in terms of the size of the area of interest, and the kind of methodology will be used. The area of interest was 50,000 km² of extension, and not just one workflow applied, those were the hardest difficulties this project overcome. An outstanding achievement was that thanks to the complexity of the project, this methodology has become a standard methodology for models on a large scale in their place to work. Additionally, I would also like to thank Dulce Tellez, Francisco Rocha, and Sergio Mata who were actively working on the project. They proactively contributed to the methodology presented. Tables

Table 1. Well’s interval velocities through the column of interest

Table 2. Well’s interval velocity values

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Graphics

Graph 1. Quality control in a cross-plot: time vs depth from TDR

References Marcos Victoria, Lugo Flores Eduardo, and Guillermo Sanchez Roa. "Depth Conversion: Application of an Innovative Methodology. Added Value To a Fractured Carbonate Reservoir Interspersed With Tertiary And Mesozoic Salt Bodies within a Very Complex Structural Setting." EUROPEC/EAGE Conference and Exhibition. Society of Petroleum Engineers, 2007.

Schultz, Phil. The seismic velocity model as an interpretation asset. Society of Exploration Geophysicists, 1998.

Carter, M. D., E. S. Siraki, and D. Coelho. "Velocity Interpretation and Depth Conversion." GP504, IHRDC, Boston (1993): 141.

Schlumberger (2015). Petrel Velocity Modeling: Training Manual. 346 p.

Nomenclature

o 2D: Two dimensional o 3D: Three dimensional o AF: Anisotropy factor o AOI: Area of interest o Der: Right (Derecha) o GOM: Gulf of Mexico o GR: Gamma Ray well log o IPN: Instituto Politécnico Nacional o Izq: Left (Izquierda) o MSL: Mean sea level o RHOB: Density Well log o TWT: Two-way time o TDR: Time Depth Relationship o UCV: Universidad Central de Venezuela o UNAM: Universidad Nacional Autónoma de México o VSP: Vertical Seismic Profile o Z: Vertical Depth measured from Mean sea level considering negative values in down direction

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4.VI AVO Analysis and Characterization of Shallow Geo-Risks: a Case Study in Deep-Water Gulf of Mexico David López Palacios (presentador); J.M. Espinosa Ortega, Instituto Mexicano del Petróleo The workflow for the analysis of shallow geohazards regarding a case conducted in deep waters of the Gulf of Mexico is exposed by applying the methodology developed by the geologists and geophysicists from the Mexican Institute of Petroleum (“Instituto Mexicano del Petróleo”) and emphasizing the usage of the analysis of the amplitude against distance in order to identify any irregularity concerning gas, shallow water flows (SWF) and methane hydrates (BSR). Introduction In this study is presented the comprehensive methodology for identifying shallow geohazards and the description of the AVO methodology applied for the quantitative analysis of shallow risks in deep waters of the Gulf of Mexico. This study is intended to analyze, through these quantitative studies of seismic data, the geological characteristics of seafloor and shallow subsurface in deep waters (up to 1,000 meters below sea level) with respect to possible geological risks. The available information regarding wells in the proximity of the study, such as the amplitude analysis, allows us to evaluate the seismic response of possible fluids trapped in shallow sands in deep waters that were considered as a risk for drilling. Therefore, delimiting their geometry and range by using some risk maps. The following is the comprehensive methodology applied in the identification of shallow risks in deep waters of the Gulf of Mexico. Shallow Geohazards Methodology As a consequence of the characteristics that put the drilling at risk, the following comprehensive methodology has been developed (Figure 1) and consists in the following phases:

• Interpretation of faults and horizons emphasizing the search for possible structural irregularities.

• Analysis of the morphology of the seafloor and stratigraphic column.

• Analysis of the “AVO” detecting irregularities regarding fluid (gas, SWF and methane hydrates).

• Time to depth conversion, geometries and thickness of the geological column.

• Assessment of results and maps of risk areas.

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The information from AVO and Shallow geohazard analysis allows the construction of a risk table, which is supports drilling of new wells, since this chart presents the risks that could occur during drilling. AVO Methodology AVO studies are conducted to analyze the behavior of ‘Amplitude Versus Offset’, and these give detailed information on the porefill. The AVO methodology (Figure 2) consists in the following phases:

• Bringing the CRP seismic gathers from the offset domain into the Angle-of-incidence’domain (AVA) to calculate Intercept (I) and Gradient which allows quick identification of anomalies of gas sand.

• AVO modeling From P Wave, S Wave, Density logs and using an elastic model, the synthetic CMP log is generated, and the AVO attributes of Intercept (I) and Gradient (G) are obtained, as well as the crossplot analysis; which identifies the AVO signature for sands with gas. The AVO response of the modeling serves to identify some areas with gas in the location.

Study case The study case is located in Cinturon Plegado Perdido (Figure 3) which is a set of elongated anticlinal structures with NE - SW direction and limited by inverse faults. The analysis was performed on a 5 km2 sub-seismic cube. There was a correlation well 4.3 km NE away from the location, which was used as a correlation well to obtain lithological information.

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Seismic Interpretation Seafloor For the analysis of the seafloor (Figure 4), the features are analyzed through seismic attributes for the identification of active faults, hydrate mounds, unstable slopes, surface channels, reefs. In addition, the direction of currents, waves and wind are taken into consideration (meta-oceanic studies).

For this study the well was in a zone less than 4 degrees of inclination, so it was in a stable area of the seabed. Structural and stratigraphic interpretation Structurally, it was interpreted as a compressive deformation for sequence 3 ( Figure 5) that goes from the upper Oligocene to the lower Miocene in which a fault was formed generating a structure that presents a dip that could favor the filling of the shallower sandy packages of sequence 2 and that during its analysis were considered as a risk due to the presence of shallow faults. In addition, amplitude anomalies are observed in the lower sequence (sequence 3) which are associated with the migration of some fluid to shallower layers. These amplitude anomalies can also be identified in the RMS attribute (right section Figure 5) as high amplitude anomalies in sequence 3. This indicates that there is a possibility that the fault is communicating deeper sandy

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sequences with the upper sequence and that through this fault fluids can migrate to younger sequences.

Methane Hydrates The presence of methane hydrates is also important, for its analysis was used the method of seismic reflection that applies the Bottom-simulating reflector (BSR) based on its characteristics. They are regularly high amplitude, since they follow the shape of the seabed they are easily recognized seismically as a multiple of the seabed (BSR). Another characteristic is that they present inverse polarity related to the seabed. In Figure 6 the seabed has positive amplitude, so the BSR would have negative polarity but in this section, we don’t observe a BSR therefore there is no presence of Methane Hydrates in the location.

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AVO Analysis The presence of fluid was evaluated with the AVO analysis. The yellow box in Figure 7 shows the shallow risk zone to be analyzed with the AVO. Also, the horizon map is shown with the amplitude envelope attribute highlighting a high amplitude anomaly over the well path, which was evaluated by the AVO analysis to identify if it corresponds to a gas risk to the well drilling.

Prior to the AVO analysis, the data conditioning was applied to attenuate coherent noise, linear noise, multiple seafloor noise and reverberations, preserving amplitude, phase and frequency in the CRP records. The yellow box in Figure 8 shows the shallow risk zone, where the amplitude increased very little with the increase against the distance, which does not define an AVO anomaly.

The records of conditioned CRPs are converted to the angle domain (AVA) using the interval velocity of the PSTM migration. The yellow box in Figure 9, shows the shallow risk zone, where the

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amplitude increases very little with the increase of the incidence angle. Also, the analysis of the Gradient attribute in seismic reflectors of interest, present a minimum amplitude increase with the incidence angle, which does not define a gas AVO anomaly. Therefore, if this anomaly does not define an AVO response, we can conclude that the high amplitude is produced only by lithological contrast.

The P*G attribute section combines high amplitude reflection and angle increment and therefore is a good checker for classic bright spot anomalies. In the yellow box area of interest (left in Figure 8), the top-base reflectors are not well defined enough to identify an AVO anomaly. In the Poisson ratio attribute section (right in Figure 10), the shallow risk zone does not show the negative-positive pair that characterize a gas AVO anomaly. An AVO anomaly in both attributes is clearly defined but in the deeper zone (where the reservoir is).

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The main outcome of the analysis with both methodologies was the separation of layers of sand with fluid content, as there was a possibility that these upper layers were connected by younger faults. From the combination of AVO attributes Gradient against Intercept, Poisson ratio and risks maps, allowed us to identify and locate AVO anomalies associated with sands saturated with fluid. Therefore, if this anomaly does not define an AVO response in the AVO attributes, we conclude that the high amplitude is produced only by lithological contrast. The information of both analysis the AVO and Shallow geohazard methodology allows to construct a table (Figure 11), integrating all the analyzed data from both: the AVO and the Shallow risks methodology.

Conclusions

• The methodologies such as “AVO” and multi-attribute analysis are highly functional for identifying the geological geohazards while drilling deep water areas.

• It is recommended to use more advanced methodologies and techniques of seismic interpretation in order to reduce the uncertainty to the minimum.

• The seismic interpreters mostly support quantitative seismic data when they count with higher resolution elements and up-to-date technologies and methodologies are applied.

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SPECIAL PRESENTATIONS SP.I Instituto Mexicano del Petróleo: Solutions for the Petroleum Industry Marco Antonio Osorio Bonilla, Director, Instituto Mexicano del Petróleo (IMP) No abstract provided

SP.II The Role of Geology in Exploration and Production: Opportunities for Technology Transfer in Mexico Ulises Neri Flores, General Director for the Promotion of Productive Chains and Investment in the Energy Sector, Economy Secretariat, Government of Mexico No abstract provided SP.III Integration of Seismic Methods and Potential Methods for Geophysical Image Building Humberto Salazar Soto (presenter), Leonardo Enrique Aguilera Gómez, Alfredo Vazquez Cantú, Pemex Exploración y Producción Oil exploration in Mexico faces great challenges mainly due to the fact of working in diverse and sometimes very complex geological conditions; such as Basins that have been affected by compressive tectonics or salt tectonics; as well as in the search for prospective resources at deeper depths. Oil exploration in Mexico with geophysical methods has more than 80 years old of history, where it has been shown over the time to be one of the most valuable tools in the integration of information for better knowledge of the subsurface and reduce geological risk in well drilling. The knowledge of the physical phenomenon, the mathematical algorithms to represent said phenomena, the evolution of technology in computer systems and electronics, have allowed the development of new and better measuring equipment with greater sensitivity and image resolution. In addition, the integration, interpretation and inverse modeling of more than one physical property of the fluid rock system has allowed the characterization and simulation studies of reservoirs to be described in greater detail. This paper will present a brief description of the technologies used in the last decade, which have allowed PEMEX to meet the goals of incorporating new reserves.

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BIOGRAPHICAL SKETCHES

WELCOME AND OPENING REMARKS Co-Chair: Elvira Pureza Gómez, President, AAPG Latin America and Caribbean Region Elvira graduated from Universidad Nacional de Colombia with a BSc degree in Geology, scholarship awarded. She holds a master degree in Geophysics and postgraduate studies on Project Management and Petroleum Geology. She has more than 20 years of experience. Started out her career in Nexen Petroleum Colombia back in 1997 and has been working continuously in different roles in exploration, new ventures, development and production, conventional and unconventional reservoirs. Currently, she is Sr. Geologist Team Lead Colombia in CNOOC International and President of the AAPG Latin America & Caribbean Region. She is an active member of AAPG, SEG and ACGGP Co-Chair: Faustino Monroy Santiago, President, AMGP Faustino is geologist graduated from the Universidad Nacional Autónoma de México (UNAM). He holds a Master's degree in Exploration of Subsurface Energy Resources also from the UNAM, and a Ph.D. from the University of Texas at Austin. He has more than 30 years of experience in the oil industry. In 1990, he started his career in Pemex where he worked in several positions. He is the author of the methodology called “EPDE” to characterize fractured reservoirs. In addition, he was co-founder and leader of the professional network of Naturally Fractured Reservoirs Characterization Specialists in Pemex. He retired from Pemex being Manager of Geosciences, Research and Technological Development. From 2016 to 2019, he worked at the National Hydrocarbons Commission (CNH) as Head of the Technical Unit for Exploration and its Supervision. He is an active member of several professional Associations and currently he is the President of the AMGP (Mexican Association of Petroleum Geologist).

SESSION I: TECTONICS AND STRUCTURAL GEOLOGY

Convener: Ricardo José Padilla y Sánchez, Universidad Nacional Autónoma de México Ricardo holds a PhD in Structural Geology and Tectonics form the University of Texas at Austin. With 50 years of professional experience, he is full time Associate Professor “C” at the División de Ingeniería en Ciencias de la Tierra, Facultad de Ingeniería, Universidad Nacional Autónoma de México. His previous experience includes Instituto de Geología, UNAM; Associate Professor at The University of Texas Pan American, Edinburg, Texas; Pemex; Comisión Federal de Electricidad; Servicos Geológicos, SA; Consultores en Geología, SA de CV. Ricardo is a member of AAPG, Academia de Ingeniería, Sociedad Geológica Mexicana, Geological Society of America and Asociación Geohidrológica Mexicana.

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Convener: Jorge Jacobo Albarrán, Instituto Politécnico Nacional Jorge holds a PhD from the University of Milan, Italy. With 39 years of professional experience, he is currently Associate Professor at the Instituto Politécnico Nacional, where focuses on petrology and tectonics. His previous experience includes 28 years working in oil exploration at the Instituto Mexicano del Petróleo. Jorge is a member of AMGP and SGM. James Pindell, Tectonic Analysis Jim earned a BSc from the Colgate University, a MSc from the State University of New York at Albany, and a PhD from Durham University UK. With 35 years of experience, he is currently Director at Tectonic Analysis Ltd. In Duncton, West Sussex, U.K., where he is on charge of leading research programs. Jim’s professional memberships includes AAPG, GSA, AGU, HGS, GCSSEPM and GSL. Md Nahidul Hasan, University of Houston Md Nahidul is a PhD student at the University of Houston, where also works as Research Assitant developing mapping and modeling tasks. Md Nahidul is a member of AAPG, AGU and GSA. Rod Grahamt, Imperial College London Rod earned a BSc from Wales University and a PhD from the Imperial College, London. During his 36 years of professional experience he has been lecturer at Swansea University and has held various positions with BP, Monument, LASMO, Emerald Energy and Hess. Currently, he is Visiting Professor at Imperial College, London. Rod is a member of AAPG and GSL. Daniel Olivares Ramos, Petroleum Geology Consultant Daniel Olivares is a geologist from the Universidad Autónoma de Nuevo León. During his 14 years of professional experience he has held positions at Pemex Exploración y Producción (Regional Geologist, Sedimentology and Stratigraphy, Salt Tectonics, Bid Rounds). Currently, he is Petroleum Geology Consultant at Black Ammonite Geoscience where is responsible for business development and geoscience solutions for Iindustry. Marlen Medina Macedo, Facultad de Ingeniería, Universidad Nacional Autónoma de México Marlen is ending a MSc in exploration and exploitation of subsoil natural resources, at Universidad Nacional Autónoma de México; in which her developed a balanced structural geological model belonging to The Gulf of Mexico. Her professional experience like a geologist engineer extends to 6 years, working in Mexican Petroleum Institute y PEMEX Exploration and Production. She has participated in multidisciplinary

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groups about hydrocarbon exploration and exploitation in Mexico, integrating and interpreting geological data, such as well cores, thin sections, well logs and 3D seismic. She has developed skills in analysis of the processes in characterization of naturally fractured reservoirs and extra heavy oil, field development, VCD and FEL documentation for the design of exploitation projects. Marlen has also participated in the construction of sedimentary and structural models. Within the most recent experience, she collaborated in geological modeling, uncertainty analysis, obtaining cases P10, P50 and P90 and the calculation of reserves for fields certification. Marlen is a member of AMGP. Bernardo Ignacio García Amador, Instituto de Geofísica, Universidad Nacional Autónoma de México Bernardo is a Geophysical engineer from Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla; earned a MSc from the Instituto de Geofísica, Universidad Nacional Autónoma de México; and is a PhD. Candidate at Instituto de Geofísica, Universidad Nacional Autónoma de México. Bernardo is a member of GSA.

SESSION II: SEDIMENTOLOGY, STRATIGRAPHY AND BIOSTRATIGRAPHY

Convener: Gustavo Murillo Muñetón, Instituto Mexicano del Petróleo Gustavo earned a BSc from Instituto Politécnico Nacional of México; a MSc from University of Southern California and a PhD from Texas A&M University. With 36 years of professional experience, he is Director of Research in Exploration and Production at Instituto Mexicano del Petróleo, where he is responsible for R&T project portfolio and management on upstream areas. Gustavo is a member of AAPG and AMGP. Convener: Ricardo Torres, Instituto Mexicano del Petróleo Ricardo Torres is a Geologist graduated from the National Polytechnic Institute and specialist in sedimentology and sandstone diagenesis. He has 35 years of Experience at the Mexican Petroleum Institute (IMP) and currently serves as the Research Manager of Predictive Geology. John W. Snedden, Institute for Geophysics, The University of Texas at Austin John earned a BA from Trinity University, a MSc from Texas A&M University, and a PhD from Louisiana State University. With 30 years of experience in the industry working at Mobil and ExxonMobil, he is currently Senior Research Scientist and Director, Gulf Basin Depositional Synthesis Research Project at the Institute for Geophysics, The University of Texas at Austin. He is responsible for Research on Gulf

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of Mexico reservoirs, supervision of students, publication of scientific papers and the book Gulf of Mexico Sedimentary Basin, Depositional Evolution and Petroleum Applications, Cambridge University Press, 2019. John is a member of AAPG, SEPM, and Gulf Coast Section of SEPM. Roberto Stanley Molina Garza, Centro de Geociencias, Universidad Nacional Autónoma de México Roberto holds a PhD from the University of Michigan. With 35 years of professional experience, he is Head Researcher B at Centro de Geociencias, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, Mexico. Roberto is a fellow member of Geological Society of America, and a member of AGU. Stephen P. J. Cossey, Cossey and Associates Inc. Stephen earned a BSc form the University of Wales, and a MS and PhD from the University of S. Carolina. With 42 years of professional experience, he is Chief Geoscientist at Cossey and Associates Inc., Durango, Colorado, USA, where he has consulted for more than 150 global exploration companies and is skilled in interpreting deepwater sequences and in creating sequence stratigraphic and depositional models from core, well, and seismic data. Dr. Cossey also teaches field excursions in France, Spain and Mexico and has conducted over 20 courses in these areas. His previous experience includes 5 years at Conoco, 12 years at BP/Sohio. Dr. Cossey is a member of AAPG, SEPM, GCSSEPM and HGS. Karyna Rodriguez, Searcher Karyna earned a BS and a MSc in Geology from the Oxford University and a MSc in Stratigraphy from the University College London. With 31 years of experience in the industry, Karyna is VP Global New Ventures at Searcher, UK, where she is responsible for developing and managing Searcher projects which support energy companies’ ongoing and future energy exploration campaigns. She previously worked in companies as British Gas, PEMEX, Apache, Pioneer. Her professional affiliations include AAPG, EAGE, PESGB, London Geological Society. José Aurelio España Pinto, Instituto Mexicano del Petróleo José Aurelio is a geological engineer from the Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico; he also earned a MSc in Geology from the Escuela Superior de Ingeniería y Arquitectura, Instituto Politécnico Nacional. With 23 years of experience working in companies as INEGI, Rotenco, Geomex del grupo DIAVAZ, he currently serves as Specialist responsible for geological and structural modeling at the Instituto Mexicano del Petróleo.

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José Aurelio is a member of AMGP and SGM. Baltazar Hernández Sánchez, Petróleos Mexicanos (PEMEX) Baltazar is a biologist from the Universidad Autonoma Metropolitana, Mexico City. With 17 years of professional experience, he currently is Cenozoic and Mesozoic Biostratigraph at Petróleos Mexicanos (PEMEX), Poza Rica, Veracruz, where is responsible for biostratigraphic analysis and interpretation of well columns, high resolution biostratigraphic stadies and sedimentology of carbonate rocks. Before PEMEX, he worked as Micropaleontology Laboratory Technical Analyst at the Instituto Mexicano del Petroleo. Baltazar is a member of AMGP and SOMEXPAL (Mexican Society of Paleontology). Afsoon Kazerouni, Bemidji State University Afsoon earned a PhD from Aarhus University, Denmark. During her 5 years of professional experience, she has been consultant in oil exploration companies internationally, and lecturer for higher education and Ministry of Environment. Currently, she is Assistant Professor of Geology at the Bemidji State University, Geology Department, Minnesota, USA. Afsoon is a member of AAPG, AGI, AWG, SPEM, GSARMS, NMN, GSA.

SESSION III: GEOCHEMISTRY AND BASIN MODELING

Convener: Sandra Ortega-Lucach, Instituto Mexicano del Petróleo Sandra earned a PhD from the University of Newcastle upon Tyne, UK. With 25 years of professional experience, she is Leader on basin analysis and petroleum systems modeling at the Instituto Mexicano del Petróleo, where she is responsible for organic geochemist research and serves as researcher advisor. Sandra is a member of AAPG, AMGP and SGM. Convener: Lourdes Clara Valdes, AMGP Lourdes is a Geologist graduated from the Instituto Politecnico Nacional in Mexico City, and she has a Master’s in Energy Resources from the Universidad Autonoma de Mexico. She has 40 years in the industry, with experience working at IMP, CAA, SA and 32 years with Pemex. Lourdes is a member of AMGE and the Mexican Geological Society and current Vice President of AMGP. She will begin her 2-year term as president at the end of the month.

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Andrew Pepper, This is Petroleum Systems LLC Andrew earned a BSc (First Class Honour). With 39 years of experience, he currently is Managing Director at This is Petroleum Systems LLC, a company he founded in 2015 as a vehicle to collaborate and innovate in Petroleum Systems concepts, modeling and training. There, he is responsible for petroleum systems analysis (tool development, research, studies). Before This is Petroleum Systems LLC, he worked at BP as leader of the Petroleum Systems Network; at Hess as Chief Geologist and then Director of New Ventures; and at BHP as VP Geoscience and VP Unconventional Exploration. Andrew is a member of AAPG, GSL, West Texas Geological Society and HGS. Alfredo E. Guzmán, Mexican Petroleum Company Alfredo earned a BSc and a MSc from Texas Tech University. With 48 years of professional experience, he is Chief Geologist at Mexican Petroleum Company, where is responsible for exploration and new ventures. Alfredo is a member of AAPG and AMGP, among other professional memberships. Mark Shann, Geomarcas SRL Mark earned a BSc Honour Degree in geology from the King’s College London (1982). His 38 years of professional experience include his work at BP International (34 years), Sierra Oil & Gas Mexico, CaribX; and Global Exploration, Appraisal and Production roles as senior geoscientist, exploration manager and company director. Currently, he is Director and Company Owner of Geomarcas SRL, at Atenas, Costa Rica. Mark is a member of AAPG and a fellow member of Geological Society of London. Mario Martínez-Yáñez, SEPI-ESIA Unidad Ticoman, Instituto Politécnico Nacional Mario is a geologist from the Instituto Politécnico Nacional, and a MSc Candidate at the same university. During his 3 years of professional experience, he has worked at BP, Züblin Ambiental and the Geology Institute of Universidad Nacional Autónoma de México. Mario is a AAPG IPN Student Chapter student member, AMGP-CDMX committee, SPE student member and GSA student member.

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Demetrio Santamaría-Orozco, Universidad Nacional Autónoma de México Demetrio earned a BSc from Universidad Nacional Autónoma de México (1984); a ME from the same university (1990); and PhD from the Technical University of Aachen, (RWTH Aachen), Germany, (2000). He has 31 years of experience as a researcher at the Mexican Petroleum Institute (IMP), and currently is a Professor at the Faculty of Engineering, Universidad Nacional Autónoma de México. His previous experience also includes Coal and Petroleum Institute, KFA, Germany. Demetrio is a member of AAPG, AMGP and SGM.

SESSION IV: GEOPHYSICS AND RESERVOIR CHARACTERIZATION

Convener: Jorge Mendoza-Amuchastegui, Instituto Mexicano del Petróleo Jorge earned a BSc in Geophysical Engineering from Universidad Nacional Autónoma de México (1984) and a MSc in Geophysics from the University of Houston (1991). He has held several positions at the Instituto Mexicano del Petróleo over 36 years, as exploration seismologist, geophysical prospecting manager, and now, upstream services Director, where he is currently responsible for the definition and deployment of business strategies and products to position IMP as a competitive upstream services provider. Jorge is a member of AAPG, EAGE, SEG and SPE. Convener: Rodrigo Hernández, Comisión Nacional de Hidrocarburos Rodrigo is a Geophysical Engineer graduated from the National Autonomous University of Mexico (UNAM), where he also obtained the Master of Science degree in Structural and Tectonic Geology. He conducted research on saline tectonics at the Higher Council of Scientific Research of in Spain before joining Pemex. He spent several years working for Pemex at the National Center for Seismological Processing and later began evaluating exploration technologies in Management and Transfer Technological Area. Rodrigo spent time working for private firms before joining the Ministry of Energy in 2008. He spent 10 years with the Mexican government, serving on various councils and committees formed to regulate hydrocarbon exploration and development. He is currently the General Director of Exploration Opinions at the National Hydrocarbon Commission (CNH), where his primary responsibilities include analyzing exploration plans and submitting them for approval. He also works professor at UNAM, teaching Geology courses in Deposits, Petroleum Geology and Geochemistry. Rodrigo is member of AAPG, EAGE, UGM and AMGP.

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Marco Antonio Arreguin, Western Geco Mexico, Central America and the Caribbean Marco Antonio is a geophysical engineer from the Universidad Nacional Autónoma de Mexico, and earned a MSc from the University of Colorado at Boulder. With 23 years of professional experience, he is Exploration Project Manager at Schlumberger, Mexico City. Before Schlumberger, he worked at Pemex Exploración y Producción. Marco Antonio is a member of AAPG, AMGE, AMGP, AIPN and SEG. Hugo Avalos Torres, Petróleos Mexicanos (PEMEX) Hugo earned a MSc in Petroleum Engineering and Natural Gas from Universidad Nacional Autónoma de Mexico. With 22 years of experience in the industry, he currently is Petrophysics Leader at PEMEX, Poza Rica, Veracruz, Mexico, where is responsible for making petrophysical model and their application to unconventional and conventional reservoirs; review, administration and control of geophysics log data base; and petrophysical evaluation to well exploration and workover in development well. Prior to PEMEX, he worked as Log Analyst and Technical Advisor in Halliburton Energy Services; Well Supervision in Services Engineer HUMAYA; Geothermic Well Geologist in Electrical Federal Commission; Investigation Support in Geological Institute, UNAM; and Investigation Support in Petroleum Mexican Institute. Hugo is a member of AMGP, EAGE, SGM and SPWLA. Rubén Nicolás-López, Instituto Mexicano del Petróleo Ruben earned a PhD in petroleum engineering from Universidad Nacional Autónoma de Mexico (UNAM) in 2006. With more than 20 years of experience he currently is Researcher and Project Leader at the Instituto Mexicano del Petróleo. He has also been Professor at UNAM. Edilberto R. Hernández Flores, Independent Consultant Edilberto is an electronic engineer from Instituto Politecnico Nacional, and earned a MSc in Energy Resources at the Universidad Nacional Autónoma de México. With 37 years of experience, he currently is Geophysics Technical Advisor and head of the course Gravity Gradiometry Tensor Applied to Oil Exploration. Prior to IMP, he worked as Seismic Supervisor at COMESA, Geophysical-Geological Interpreter at PEMEX, Geophysics Technical Advisor at Edcon PRJ, and other companies such as Nutech Energy Alliance-ITS, NET BRAINS and IPN. Edilberto is a member of AAPG, AMGP and AMGE.

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Moises Huicochea Campos, Schlumberger Moises is a geophysical engineer from Universidad Nacional Autónoma de México; and earned a MBA In Renewable Energy from Instituto Tecnológico de Estudios Superiores de Monterrey. With 17 years of experience, he has held several positions with Schlumberger in Venezuela and South America. Currently, he is Geoscience Technical Sales Solution for Mexico and Central America, where is responsible for detection and development of geoscience business in Mexico and Central America. Moises is a member of AMGE and Mexican Geophysical Association. David López Palacios, Instituto Mexicano del Petróleo David is a geophysical engineer from Benemérita Universidad Autónoma de Puebla; and is a Master in Engineering student at Instituto Mexicano del Petróleo. With 9 years of professional experience, he is certified on petroleum system and basin analysis by the University of Alberta and UNAM. Is responsible for structural and stratigraphic seismic interpretation, and geomechanics, applied to prospects for reservoir characterization and exploratory wells. He collaborates in working teams for the VCD program in shallow, deep, and ultra-deep waters. Currently, David is a Seismic Interpreter at the Instituto Mexicano del Petróleo and has 2 years of experience in acquisition of seismic data.

SPECIAL PRESENTATIONS

Marco Antonio Osorio Bonilla, Director, Instituto Mexicano del Petróleo (IMP) Marco Antonio Osorio Bonilla serves as General Director of the Mexican Petroleum Institute. He has 38 years of professional experience, and nearly two decades with IMP. Before being named General Director by President Andrés Manuel López Obrador, he held several management level positions, including Director of Product Technology, Engineering and Process Service Manager and head of the Institute’s Central Regional Directorate. As General Director, Mr. Osorio works to strengthen the role of the Mexican Petroleum Institute as the technological arm of Pemex and of the hydrocarbon industry, both within Mexico and internationally. He also is helping the IMP to establish itself as the federal government consultant on energy matters. He has a chemical engineering degree from the Instituto Politécnico Nacional in Mexico City, ad certificate in Project Administration and Cogeneration from the Universidad Nacional Autónoma de México and the Colegio Universitario Mexicano. Ulises Neri Flores, General Director for the Promotion of Productive Chains and Investment in the Energy Sector, Economy Secretariat, Government of Mexico

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Humberto Salazar Soto, Geophysical Studies Manager, PEMEX Humberto is a geophysical engineer graduated from the Instituto Politecnico Nacional. He holds a Master's degree in Petroleum Project Management from the Universidad de las Americas. With 37 years of professional experience, he is currently Geophysical Studies Manager at Pemex Exploración y Producción, Villahermosa, where is responsible for Geophysical data acquisition and processing. Prior to Pemex, he worked at DIAVAZ, Comisión Nacional de Hidrocarburos, CGG, GSI, National Seismological Service, Perforadata. Humberto is a member of AAPG, AMGE, SEG and EAGE.

CLOSING PANEL DISCUSSION Moderator: Faustino Monroy Santiago, President, AMGP Faustino is geologist graduated from the Universidad Nacional Autónoma de México (UNAM). He holds a Master's degree in Exploration of Subsurface Energy Resources also from the UNAM, and a Ph.D. from the University of Texas at Austin. He has more than 30 years of experience in the oil industry. In 1990, he started his career in Pemex where he worked in several positions. He is the author of the methodology called “EPDE” to characterize fractured reservoirs. In addition, he was co-founder and leader of the professional network of Naturally Fractured Reservoirs Characterization Specialists in Pemex. He retired from Pemex being Manager of Geosciences, Research and Technological Development. From 2016 to 2019, he worked at the National Hydrocarbons Commission (CNH) as Head of the Technical Unit for Exploration and its Supervision. He is an active member of several professional Associations and currently he is the President of the AMGP (Mexican Association of Petroleum Geologist). Ricardo José Padilla y Sánchez, Universidad Nacional Autónoma de México Ricardo holds a PhD in Structural Geology and Tectonics form the University of Texas at Austin. With 50 years of professional experience, he is full time Associate Professor “C” at the División de Ingeniería en Ciencias de la Tierra, Facultad de Ingeniería, Universidad Nacional Autónoma de México. His previous experience includes Instituto de Geología, UNAM; Associate Professor at The University of Texas Pan American, Edinburg, Texas; Pemex; Comisión Federal de Electricidad; Servicos Geológicos, SA; Consultores en Geología, SA de CV. Ricardo is a member of AAPG, Academia de Ingeniería, Sociedad Geológica Mexicana, Geological Society of America and Asociación Geohidrológica Mexicana.

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Sandra Ortega-Lucach, Instituto Mexicano del Petróleo Sandra earned a PhD from the University of Newcastle upon Tyne, UK. With 25 years of professional experience, she is Leader on basin analysis and petroleum systems modeling at the Instituto Mexicano del Petróleo, where she is responsible for organic geochemist research and serves as researcher advisor. Sandra is a member of AAPG, AMGP and SGM. Gustavo Murillo Muñetón, Instituto Mexicano del Petróleo Gustavo earned a BSc from Instituto Politécnico Nacional of México; a MSc from University of Southern California and a PhD from Texas A&M University. With 36 years of professional experience, he is Director of Research in Exploration and Production at Instituto Mexicano del Petróleo, where he is responsible for R&T project portfolio and management on upstream areas. Gustavo is a member of AAPG and AMGP. Jorge Mendoza-Amuchastegui, Instituto Mexicano del Petróleo Jorge earned a BSc in Geophysical Engineering from Universidad Nacional Autónoma de México (1984) and a MSc in Geophysics from the University of Houston (1991). He has held several positions at the Instituto Mexicano del Petróleo over 36 years, as exploration seismologist, geophysical prospecting manager, and now, upstream services Director, where he is currently responsible for the definition and deployment of business strategies and products to position IMP as a competitive upstream services provider. Jorge is a member of AAPG, EAGE, SEG and SPE.

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