SEG 2009 Workshop SEAM Phase I Model. Outline Model Overview - Structural Macro view Model scale and...
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Transcript of SEG 2009 Workshop SEAM Phase I Model. Outline Model Overview - Structural Macro view Model scale and...
SEG 2009 WorkshopSEG 2009 Workshop
SEAM Phase I ModelSEAM Phase I Model
SEAM Phase I ModelSEAM Phase I Model
OutlineOutlineModel Overview - Structural Macro viewModel Overview - Structural Macro view
Model scale and domainModel scale and domain
The SaltThe Salt
Major Sedimentary Surfaces Major Sedimentary Surfaces
Special surfaces (i.e. Salt, sutures, sediment raft, faults ) Special surfaces (i.e. Salt, sutures, sediment raft, faults )
Adding fine layered properties within macro structureAdding fine layered properties within macro structure
Construction processConstruction process
From Surfaces to Stratigrphic GridsFrom Surfaces to Stratigrphic Grids
Rock Properties.Rock Properties.
Rock Physics and Reservoirs Rock Physics and Reservoirs
Model propertiesModel properties
SEAM Phase I ModelSEAM Phase I Model
Model Overview – ComponentsModel Overview – Components
I) ProvenanceI) Provenance A deep water Gulf of Mexico salt domain analogueA deep water Gulf of Mexico salt domain analogue ..
II) Major Structural FeaturesII) Major Structural Features 1 Complex salt body with a rugous top, a root, and overhangs1 Complex salt body with a rugous top, a root, and overhangs 9 Horizons that extend across the entire model9 Horizons that extend across the entire model 12 Radial faults arrayed under salt and near to the salt root stock12 Radial faults arrayed under salt and near to the salt root stock 1 Overturned sediment raft proximate to salt root1 Overturned sediment raft proximate to salt root 2 internal sutures in salt and a heterogeneous salt cap2 internal sutures in salt and a heterogeneous salt cap
III) Special Features in the modelIII) Special Features in the model Reservoirs, Difractors, SEG stamp, Fine layering, Multiple propertiesReservoirs, Difractors, SEG stamp, Fine layering, Multiple properties
SEAM Phase I ModelSEAM Phase I Model
Model Overview - Volume of InterestModel Overview - Volume of Interest • Size and OrientationSize and Orientation
35km EW x 40km NS x 15km Depth (27 x SEG Salt)35km EW x 40km NS x 15km Depth (27 x SEG Salt)
E-W = XE-W = X N-S = Y N-S = Y Depth=ZDepth=Z
• XYZ Origin = (0,0,0) XYZ Origin = (0,0,0) • Grid SizeGrid Size
properties were built on 10m and 20m grid spacingproperties were built on 10m and 20m grid spacing
10m 10m 84.1gb/property 84.1gb/property (21 billion cells = 220x SEG Salt)(21 billion cells = 220x SEG Salt)
20m20m 10.52gb/property 10.52gb/property
x-y-z storage orderx-y-z storage order
Phase I Model – A complex deep water salt model
Top View
35 Km
View from west
40 km
View from east
40 km
SEAM Phase I ModelSEAM Phase I Model
Model OverviewModel Overview - - The major sediment horizonsThe major sediment horizons1.1. BasementBasement
2.2. Top Mother SaltTop Mother Salt
3.3. MCU (Mid Cretaceous Unconformity)MCU (Mid Cretaceous Unconformity)
4.4. Top Olicoene/Paleogene “4_Oligocene”Top Olicoene/Paleogene “4_Oligocene”
5.5. Top Lower Miocene “5_Miocne_1”Top Lower Miocene “5_Miocne_1”
6.6. Top Mid Miocene “6_Miocene_2”Top Mid Miocene “6_Miocene_2”
7.7. Miocene Pliocene Unconformity “8_Mio_Plio_UNCF”Miocene Pliocene Unconformity “8_Mio_Plio_UNCF”
8.8. Top PlioceneTop Pliocene
9.9. Water BottomWater Bottom
A Blank Canvas
Flat Basement, Z=14858m
Top Mother Salt
MCU – Top Cretaceous
MCU – with radial faults
MCU – with salt removed
Oligocene
Miocene_1, top of lower Miocene
Miocene_2, top mid Miocene
Mio-Plio Unconformity - uncut
Pliocene - uncut
Water Bottom
SEAM Phase I ModelSEAM Phase I Model
Model Overview – Other Special Surfaces1. Salt Sutures – entrained thin sediment
2. Overturned sediment raft
3. Radial Faults
Salt suture sufaces
Salt suture sufaces - zoom
Radial fault surfaces (12)
Overturned sediment raft
Sediment raft relative to salt - density
SEAM Phase I ModelSEAM Phase I Model - Going from macro structure to fine layered detail -
Model Construction Work Flow• Build salt surface
- Construct patches from top and base interpretations- Merge salt patches into hermetically sealed surface. - Iterative revisions to address concerns
• Construct sediment surfaces for a cellular version of the model - used both triangulated and regular 2D gridded objects- Introduce faults into surfaces and make consistent with faults
• Build indicator volume to flag model regions• Form stratigraphic reservoir grids from bounding surfaces• For 7 major sedimentary units and each property (Vp,Vs, , Rn, Rt )
- Morph properties from a local cartesian grid to a strat-grid- Transfer property from the strat grid to the global cartesian grid
• Mask in salt & overturned sediment raft after property set on major units • Interpolate | average | smooth to final 10m grid
SEAM Phase I Model SEAM Phase I Model Indicator VolumeIndicator Volume
2
10
15
179
13
12
11
14
Basement 1
Mother Salt 2
Cretaceous 3
Oligocene-Paleo 4
Lower Miocene 5
Middle Miocene 6
Upper Miocene 7
Pliocene 8
Pleistocene 9
Water 10
Inv. Lower Mio. 11
Inv. Olig-Paleog. 12
Inv. Cretaceous 13
Salt Suture 14
Salt 15
Hetero Salt 17
Bounding surfaces to define Pliocene reservoir grid
Pliocene density on UVW grid
Pliocene density morphed from UVW to XYZ strat-grid
421 million cells – 1 of 7 grids
Density transferred to Cartesian global grid
channel
turbidite fan
salt
SEAM Phase I ModelSEAM Phase I Model
Model Overview – Reservoirs and StatisiticsModel Overview – Reservoirs and StatisiticsCatalogueCataloguePleistocene Pleistocene 5 small turbidite fans5 small turbidite fans
Pliocene Pliocene 2 E-W trending braided channel systems2 E-W trending braided channel systems
Upper Miocene Upper Miocene 2 N-S trending braided channels in eastern half 2 N-S trending braided channels in eastern half
Middle Miocene Middle Miocene 2 Large turbidite fans that enter from North 2 Large turbidite fans that enter from North
Lower Miocene Lower Miocene 2 Large turbidite fans that enter from North 2 Large turbidite fans that enter from North
SEAM Channel and Turbidite ReservoirsSEAM Channel and Turbidite Reservoirs
Rock Properties & Physical Properties
• Conceptual Framework•Rock Properties•Statistics•Channel Procedure•Turbidite procedure
SEAM Phase I ModelSEAM Phase I Model
Rooting the seismic simulation back into the rock properties ( Conceptual Framework for SEAM Model )
Rock PropertiesVshale, Porosity, Fluids,Sat, Pressure, Resis, …
Elastic ParmsVp, Vs, Dn, Cij, Q(and their reflectivities)
Seismic WavesP, S, qP,S, atten/disp; EM response, Gravity
AVO reflectivity inversionfor elastic parameters
Elasticity inversionfor rock/reservoir properties
Elastic parameter modelingfrom Rock properties
Seismic modeling fromElastic parameters
Interest groups on this end:Imagers, Tomographers, Processors
Interest group on this end:Reservoir characterization and Monitoring
The Rock Property Is The Root of Seismic Behavior
The earth model is rooted in the rock properties to force physical consistency across derived elasticity parameters!
Several independent rock properties form the “basis functions” from which all elastic parameters are consistently derived via rock physics + well statistics!
Properties(X,Y,Z) in ~ order of significance:Vshale: varies from 0 to 1 and indicates the relative volume of sand and shale
lithologies; in this case shales are taken to be interbedded with sands.Porosity of the Sand endmember: variable and germane to fluid substitutionPorosity of the Shale endmember: variable but not involved in fluid substitutionPore Fluid: (type and saturation) affects bulk modulus of sand via GassmannResistivity: bed-normal and bed-parallel anisotropyNet Pressure: most important for soft sands, but not significant in model
Rock physics & well statistics information:Porosity Depth Trend: scaffold on which porosity variation is superposedCementation/Diagenesis: provides the steep modulus vs porosity trendDeposition (sorting etc.): provides the shallow modulus vs porosity cross-trendGassmann & simple contact theory: fluid and overpressure effectsPorosity retention with burial/uplift: V contours parallel neither structure nor seafloorArchie’s Law: for ionic flow in porous sand, also ~ modified for shales
SEAM STRATIGRAPHY
•Rock properties based on generated statistics
•Could base properties on real data statistics
Cre
t
P
al O
lig
Lo
Mio
Md
Mio
Up
Mio
Plio
P
leis
to
sheet turbidites
sheet turbidites
stacked channels
leaf turbidites
marl streaks
leaf turbidites
stacked channels not in section
Stratigraphic vshale section (white=sandier)Cross-section shows vshale statistics on flat UVW grid
SUMMARY OFCHANNEL RESERVOIR ARCHITECTURE
Channels at one depth level. Channels are 20 m thick, and top rectangle is 35 km long (EW) X 10 km wide (NS). Two channels per depth level, 12 depth levels in the channel complex for a total complex thickness of 240 meters. Each level of the 12 has a different but statistically similar pair of channels.
Zoom of above, ~ 11 km long. Individual channels average ~180 m across*Within* channels, red ~ 5% vsh, light green ~ 25% vsh, blue ~ 60% vsh;Outside of channels = background shale from main model
The main statistical features of the channels (length, width, thickness, sinuosity, vshale distribution) come from real world measurements of hi-res seismic and outcrop observations.
SAME upper panel as in previous slide.
Image of the average vshale vertically averaged through all 12 depth levels of the channel complex. Now, red ~ 50% vsh, blue ~ 80% vsh (because of partial averaging contribution from background vsh of ~100%) . The complex is just over one wavelength thick, so this image represents what a medium wavelength wave could sense. Individual channels are from 150 to 220 m wide; entire channel complex about 2 to 3 km wide
Zoomed on next slide
Zoom of previous panel. ~ 5 km left to right. The blue-green part of the channel complex is about 1.6 km across . The individual 20 m cells are visible at this scale. Blue disk represents a dominant wavelength of about 200 meters (3000 m/s / 15 Hz). Effective imaging resolution will be poorer given noisy data, subsalt illumination, and inaccurate velocity model.Find the sweet spots in the channels.
SUMMARY OFTURBIDITE RESERVOIR ARCHITECTURE
1. Turbidite channels digitized from high-resolution, near surface seismic images of recent turbidites.2. This and two other templates rotated and stretched to produce multiple turbidite complexes.3. Each filamentary channel “dressed up” with vshale and width variations.4. Full turbidite complexes superposed and scattered across the various reservoir strat levels.
Superposed on salt for orientation. Entire 35 km width of model shown. Yellow bars = 10 km
200 m vertical average of “dressed” turbidite vshale: white=sandier, blue=shalierChannel elements narrow distally: start at 240 m width in throat, end up 70 m wide
Mid Miocene Reservoirs: vshale(red = sand, white = shale)
Multiple turbidite complexes. Similar fans superposed over 4 consecutive 20-m layers (80 m thick complex), followed by 40 m of shale, followed by another similar 80 m thick complex.
10 km
SAMPLE WELL LOGS
Well x=900 y=983 cells (eroded)
0
0.2
0.4
0.6
0.8
1
0 2000 4000 6000 8000 10000 12000 14000Depth BML (m)
No
rmal
ized
Un
its
vshnorm
Vpnorm
Dnnorm
Por
Reflecnorm
Vptomonorm
Central Model. NOTE: depths = strat cell X 20m, so gradients are not “perfect” due to lack of absolute depth warping
Two Reservoir Penetrations
9Pleist 8Plio 7UpMio 6MdMio 5LoMio 4OligPaleo 3Cret
Mio
Plio
UN
CF
turbiditereservoirs
gas
oil
oil
oil
1D (0-offset) Reflectivity convolved with 0-3-12-25 Hz 0-phase Ormsby bandpass filter Y=cell 1000
NOTE: These were created separately and glued together, so in this figure there is *no* reflectivity present at the macrolayer boundaries.
3Cre
t 4
Olig
Pale
o
5Lo
Mio
6M
dMio
7U
pMio
8
Plio
9
Plei
st< Small Reservoir
Chaotic Pleistocene< Small Reservoir
< Channel Reservoir (not visible here)
< Channel Reservoir
< Turbidite Reservoir
< Top overpressure< Turbidite Reservoir
< Bot overpressure
< Olig marlstones
< Low coherency, low amp Paleogene
< Hi amp sandy carbonates in Cret
ExampleSeismicSection
Special Features – SEG density logo
Special Features – deep density difractors
Special Features – radial faults
Shallow difractors in density
Special Features – shallow difractors
SEAM Phase I ModelSEAM Phase I Model
Existing Model PropertiesExisting Model Properties• VpVp P-wave velocityP-wave velocity
• densitydensity
• RRn, R, Rt normal and transverse resistivity
• Vs Shear velocity
Distinctive Nature of SEAM model• Geophysical Properties based on Rock properties• Scale of model and fine scale statistics• To elasticity and beyond - Vs is future aspiration
SEAM Phase I ModelSEAM Phase I Model
AcknowledgmentsAcknowledgments• Many thanks to Joe Stefani, Dean Stoughton, Edward Many thanks to Joe Stefani, Dean Stoughton, Edward
Naylor, Joachim Blanche, Jacques Leveille for time Naylor, Joachim Blanche, Jacques Leveille for time spent constructing the modelspent constructing the model
• Mike Fehler for managing a distributed processMike Fehler for managing a distributed process• To the management of sponsor companies that allowed To the management of sponsor companies that allowed
their employees to contribute to this industry project.their employees to contribute to this industry project.• The SEG for providing assistance and guidance.The SEG for providing assistance and guidance.