RESOURCE ASSESSMENT Michael Hohn, Susan Pool, and Jessica Moore West Virginia Geological & Economic...
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Transcript of RESOURCE ASSESSMENT Michael Hohn, Susan Pool, and Jessica Moore West Virginia Geological & Economic...
RESOURCE ASSESSMENT
Michael Hohn, Susan Pool, and Jessica Moore
West Virginia Geological & Economic Survey
Background
Approaches to estimating hydrocarbon volumes for continuous unconventional reservoirs:• Use production data to estimate
recoverable resources directly
• Use geologic data to estimate original hydrocarbons-in-place from which recoverable resources can be determined
Background• All hydrocarbon that
could be produced (varies):– Technically recoverable (TRR)--
function of geology and technology
– Economically recoverable (ERR)--function of geology, technology, and economics
• All the hydrocarbon that exists (fixed):– Original hydrocarbon-in-place
(OHIP)--function of geology
Modified from Boswell
REMAINING RESOURCES
Assessment of Utica Shale Play Remaining Resources
Methodology
• Probability-based U.S. Geological Survey method
• Uses distributions for total assessment unit area, areas of sweet spots, EUR, and success rates
• Excludes wells already producing• Monte Carlo sampling of distributions for
mean, median, 5%, 95% values for total resource
Steps
• Definition of total assessment units• Delineation of minimum, median,
maximum area of sweet spots• Decline curve analysis for determining
estimated ultimate recoveries• Success ratios• Drainage areas
Assessment Units
Producing Oil Wells
Condensate/NGL Production
Producing Gas Wells
Definition of Assessment Units: Thermal Maturity
Gas Prone
Wet Gas
Oil ProneOvermature
Definition of Assessment Units: Oil Sweet Spot
Definition of Assessment Units: Oil Sweet Spot
Definition of Assessment Units: Wet Gas Sweet Spot
Assessment Units and Sweet Spots
Oil
Sw
eet
Spo
t M
inim
um
Oil Sweet Spot
Minimum
Oil Sweet Spot
Maximum
Wet Gas Sweet Spot
Maximum
Wet Gas Sweet Spot
Minimum
Dry Gas Sweet Spot
Maximum
Dry Gas Sweet Spot
Minimum
Estimated Ultimate Recovery
Estimated Ultimate Recovery
0 5 10 15 20 25 30 35 40 450
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Months
Ba
rre
ls O
il
Estimated Ultimate Recovery
0 5 10 15 20 25 30 35 40 450
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Median 1 year
Median 2 years
Median 3 years
Median 4 years
Median
Months
Ba
rre
ls O
il
EUR Model
0 20 40 60 80 100 1200
50,000
100,000
150,000
200,000
250,000
300,000
350,000
Median 1 year
Median 2 years
Median 3 years
Median 4 years
Median
Minimum EUR model
Median EUR Model
Maximum EUR Model
Months
Ba
rre
ls O
il
EUR Distributions
Oil AU (MMbo) Min Med Max
Sweet Spot 0.022 0.199 0.628
Non Sweet Spot 0.002 0.022 0.049
Wet Gas AU (Bcf) Min Med Max
Sweet Spot 0.64 5.76 18.84
Non Sweet Spot 0.20 0.64 1.19
Gas AU (Bcf) Min Med Max
Sweet Spot 0.19 7.09 30.37
Non Sweet Spot 0.039 0.19 0.32
Success Rates
Oil AU (%) Min Med Max
Sweet Spot 90 95 99
Non Sweet Spot 1 3 5
Wet Gas AU (%) Min Med Max
Sweet Spot 90 95 99
Non Sweet Spot 5 10 40
Gas AU (%) Min Med Max
Sweet Spot 90 95 99
Non Sweet Spot 5 10 40
Results
Oil Assessment Unit
OIL MMbo Gas Bcf
F95 F50 F5 Mean F95 F50 F5 Mean
Sweet Spot 733 1,677 3,744 1,908 2,231 6,636 17,722 7,949
NonSweet Spot 23 49 91 52 69 191 446 216
Total 791 1,728 3,788 1,960 2,370 6,858 17,960 8,165
Wet Gas Assessment Unit
OIL MMbo Gas Bcf
F95 F50 F5 Mean F95 F50 F5 Mean
Sweet Spot 23,840 49,601 106,550 55,980
NonSweet Spot 99 379 1,023 447
Total 24,484 50,037 106,852 56,427
Gas Assessment Unit
OIL MMbo Gas Bcf
F95 F50 F5 Mean F95 F50 F5 Mean
Sweet Spot 220,473 590,680 1,542,873 710,341
NonSweet Spot 2,862 6,584 13,835 7,238
Total 228,478 598,026 1,549,586 717,579
ORIGINAL IN-PLACE RESOURCES
Assessment of Utica Shale Play In-Place Resources using
Volumetric Approach
Purpose
• Estimate original hydrocarbon-in-place volumes for selected stratigraphic units
• Determine general overall hydrocarbon distribution
• Examine key parameters that may impact hydrocarbon distribution
Methodology and Data
Use geologic data and volumetric approach to estimate total original hydrocarbon-in-place (OHIP):
OHIP = Free + Adsorbed
Methodology and Data
Use geologic data and volumetric approach to estimate total original hydrocarbon-in-place (OHIP):
OHIP = Free + Adsorbed
Free Hydrocarbon-in-PlaceOGIPfree = (feff * (1-Sw) * (1-Qnc) * Hfm * Ar * 4.346*10-5 ) / FVFg
OOIPfree = (feff * (1-Sw) * Hfm * Ar * 7758) / FVFo
Adsorbed Hydrocarbon-in-PlaceOGIPadsorb = Gc * rfm * Hfm * Ar * 1.3597*10-6
?OOIPadsorb= S2 * 0.001 * rfm * Hfm * Ar * 7758
Hfm , rfm , f, and Sw
are derived from Utica Project well logs
with f and Sw adjusted for Vsh and Vker
TOC
is from Utica Project sample/well log data
Gc
is from publicly-available isotherms
given TOC and pressure
FVF
is derived from Utica Project well logs and other publicly-available data
given temperature, pressure, and gas compressibility
Methodology and Data
Methodology and Data
1. Identify and select wells meeting approach criteria
2. Examine stratigraphic picks and well log data
3. Select and extract well log data
4. Compile and derive additional required data
5. Process data and estimate volumes
6. Correct and refine data
Methodology and Data
Searching for:• Utica, Point Pleasant, Logana penetrations
• Top depth no less than 2,500 feet (initial); ~3,000 feet (final)
• Digital well logs with, at minimum, gamma ray, bulk density/porosity, resistivity traces
• Vertical non-faulted wells
• Even geographic distribution
Step 1—Identify and Select Wells
Methodology and DataStep 1—Identify and Select Wells
Digital logs for wells with Utica, Point Pleasant, and/or Logana identified plus top depth greater than 2500 feet
Methodology and DataStep 1—Identify and Select Wells
Full suite digital logs for wells with Utica, Point Pleasant, and/or Logana identified plus top depth greater than 2500 feet
Methodology and DataStep 1—Identify and Select Wells
Full suite digital logs for wells with Utica, Point Pleasant, and/or Logana identified plus top depth greater than 2500 feet
Note: Limited digital well log data
Thermal maturity as determined from equivalent %Ro
• Determined level of maturity for selected wells based on equivalent %Ro map
• Divided in-place assessment into gas and oil regions
• Assumed single phase in each hydrocarbon region
Methodology and DataStep 1—Identify and Select Wells
Methodology and DataStep 2—Examine Stratigraphic Picks and Logs
Example digital well log data with stratigraphic units identified;used to review log availability through units plus assess log quality
Methodology and DataStep 3—Select and Extract Log Data
Example digital well log data with stratigraphic units identified;used to review log availability through units plus assess log quality
Log data:• Gamma ray• Density and porosity• Resistivity• Temperature• TOC
Notes:• Normalized• Sample interval=0.5 feet
Methodology and Data
Including:• Total Organic Carbon
• Pressure
• Volume of Shale
• Temperature
• Gas Content
Step 4—Compile and Derive Additional Data
Methodology and DataStep 4—Compile and Derive Additional Data
Mean total organic carbon (%) for Utica Shaleas derived from Consortium analytical data
TOC
Methodology and DataStep 4—Compile and Derive Additional Data
Mean total organic carbon (%) for Point Pleasant Formationas derived from Consortium analytical data
TOC
Methodology and DataStep 4—Compile and Derive Additional Data
Mean total organic carbon (%) for Logana Member of Trenton Limestoneas derived from Consortium analytical data
TOC
Methodology and Data
Had limited reservoir pressure data. From formation-specific well data for WV and OH, Consortium partner input, and publicly-available data; assumed pressure gradients (psi/ft) of:• 0.433 for NY and 0.6 for remaining area except...
• 0.5 in very small portion of southern NY
• 0.7 in small portion of north central PA
• 0.7-0.9 in small area including southwestern PA, northern WV panhandle, and east central OH
Step 4—Compile and Derive Additional Data
Pressure
Methodology and Data
Corrected for volume of shale as extracted from: • X-ray diffraction (XRD) data
• Maps from XRD data
• Gamma ray well logs plus XRD data
Step 4—Compile and Derive Additional Data
Volume of Shale
Methodology and DataStep 4—Compile and Derive Additional Data
Temperature gradientas derived from the National Geothermal Project data
Temperature
Methodology and DataStep 4—Compile and Derive Additional Data
Gas content determined from publicly-available isothermsgiven total organic carbon (TOC) and pressure
Advanced Resources International, Inc.
• CH4 isotherm for NY
• Isotherm used for NY, majority of PA, and WV given TOC and pressure
• CH4 isotherm for various states
• Isotherm used for OH given TOC and pressure
• Isotherm values from NY and OH averaged for northwestern corner of PA given TOC and pressure
Gas Content
Methodology and DataStep 5—Process Data and Estimate Volumes
a. Estimate effective porosity
b. Estimate water saturation
c. Estimate formation volume factor
d. Estimate free hydrocarbon volumes
e. Estimate adsorbed hydrocarbon volumes
Methodology and DataStep 5—Process Data and Estimate Volumes
Porosity Notes:
• Determined density porosity from bulk density or used density porosity
• Used both density and neutron porosity if available
• Corrected for Vsh as extracted from XRD data, maps from XRD data, and gamma ray well logs+XRD data
• Corrected for Vker as extracted from maps assuming linear relationship between TOC and Vker
Methodology and DataStep 5—Process Data and Estimate Volumes
Water Saturation Notes:
• Used Simandoux equation
• Used A=1, M=1.7, and N=1.7
• Corrected for Vsh as extracted from XRD data, maps from XRD data, and gamma ray well logs+XRD data
• Corrected for Vker as extracted from maps assuming linear relationship between TOC and Vker
Methodology and DataStep 5—Process Data and Estimate Volumes
Additional Notes:
• Used TOC from Utica Project analytical data and maps rather than using TOC from Passey method
Stratigraphic Unit
Original In-Place Resources,Average Volumes Per Unit Area
Oil (MMbo/mi2)* Gas (Bcf/mi2)*
Utica Shale 20.8 53.5
Point Pleasant Formation 15.8 85.1
Logana Member of Trenton Limestone 3.0 17.0
Preliminary summary results
* = average volume per square mile in the sweet spot area; sweet spot area is as defined to estimate remaining recoverable resources using the probabilistic (USGS-style) approach
Step 5—Process Data and Estimate VolumesMethodology and Data
Utica Shale original in-place volumes per unit area,preliminary summary results
average volume per square mile in the sweet spot area; sweet spot area is as defined to estimate remaining recoverable resources using the probabilistic (USGS-style) approach
Methodology and DataStep 5—Process Data and Estimate Volumes
Supplemental Slide 1
DISCLAIMER: This map is a preliminary draft which reflects data and analyses current as of July 14, 2015.The volumetric calculations and derivative maps will likely change as additional data become available and techniques are refined. Users are cautioned that this map represents only a best estimate of trends given limited available data and should not be used as a stand-alone product.
average volume per square mile in the sweet spot area; sweet spot area is as defined to estimate remaining recoverable resources using the probabilistic (USGS-style) approach
Methodology and DataPoint Pleasant Formation original in-place volumes per unit area,
preliminary summary results
Step 5—Process Data and Estimate Volumes
Supplemental Slide 2
DISCLAIMER: This map is a preliminary draft which reflects data and analyses current as of July 14, 2015.The volumetric calculations and derivative maps will likely change as additional data become available and techniques are refined. Users are cautioned that this map represents only a best estimate of trends given limited available data and should not be used as a stand-alone product.
average volume per square mile in the sweet spot area; sweet spot area is as defined to estimate remaining recoverable resources using the probabilistic (USGS-style) approach
Methodology and DataLogana Member of Trenton Limestone original in-place volumes per unit area,
preliminary summary results
Step 5—Process Data and Estimate Volumes
Supplemental Slide 3
DISCLAIMER: This map is a preliminary draft which reflects data and analyses current as of July 14, 2015.The volumetric calculations and derivative maps will likely change as additional data become available and techniques are refined. Users are cautioned that this map represents only a best estimate of trends given limited available data and should not be used as a stand-alone product.
Stratigraphic Unit
Original In-Place Resources,Total Volumes
Oil (MMbo)* Gas (Bcf)*
Utica Shale 43,508 1,098,119
Point Pleasant Formation 33,050 1,745,803
Logana Member of Trenton Limestone 6,345 348,476
Preliminary summary results
* = estimated volume in the sweet spot area; sweet spot area is as defined to estimate remaining recoverable resources using the probabilistic (USGS-style) approach
Step 5—Process Data and Estimate VolumesMethodology and Data
Resources Oil (MMbo)* Gas (Bcf)*
Recoverable Resources
2,611 889,972
Original In-Place Resources
82,903 3,192,398
Current Recovery Factors
3% 28%
* = estimated volume in the sweet spot area; sweet spot area is as defined to estimate remaining recoverable resources using the probabilistic (USGS-style) approach
Comparison of Results
Issues
• Limited amount of full-suite well log data especially for Pennsylvania and West Virginia
• Limited formation pressure data
• Limited core data for log-to-core calibration
Supplemental Slide 4
Potential Future Work
• Incorporate additional data from supplemental sources (e.g. IHS)
• Incorporate additional data from wells with less than full suites of log data
• Investigate additional data processing techniques
• Conduct sensitivity analysis
• Update EUR’s and sweet spots as play develops
Supplemental Slide 5