This report presents the methodology used in the geology-based assessment of the in-place oil resources in 18 oil shale zones of the Eocene Green River Formation in the Uinta Basin of northeastern Utah. The focus is on the methodology used to (1) convert legacy data; (2) analyze the data through application of current computer techniques; and (3) ultimately quantify the resultant data using spreadsheet, database, and geographic information systems (GIS) software.

A detailed description of the methodology employed to perform a geology-based assessment of in-place oil shale and nahcolite resources in the Piceance Basin of northwestern Colorado is presented here. Considerable advancements in computer and database technology since the previous oil shale assessment in 1989 provided the U.S. Geological Survey (USGS) assessment team with new tools to convert legacy data, store and manipulate new data, perform calculations, and quantify, report, and display the assessment results. Relational database and geographic information systems (GIS) software were used seamlessly to streamline the storage and manipulation of the data. A deterministic spatial interpolation method, the Radial Basis Function (RBF), was used to generate isopach and isoresource models in the GIS software, which provided a spatial statistics function to summarize the prediction models and determine the in-place oil shale and nahcolite resource totals.

A detailed description of the methodology employed to perform a geology-based assessment of in-place oil shale and nahcolite resources in the Piceance Basin of northwestern Colorado is presented here. Considerable advancements in computer and database technology since the previous oil shale assessment in 1989 provided the U.S. Geological Survey (USGS) assessment team with new tools to convert legacy data, store and manipulate new data, perform calculations, and quantify, report, and display the assessment results. Relational database and geographic information systems (GIS) software were used seamlessly to streamline the storage and manipulation of the data. A deterministic spatial interpolation method, the Radial Basis Function (RBF), was used to generate isopach and isoresource models in the GIS software, which provided a spatial statistics function to summarize the prediction models and determine the in-place oil shale and nahcolite resource totals.

ESRI GRID raster datasets were created to display and quantify oil shale resources for eighteen zones in the Uinta Basin, Utah and Colorado as part of a 2010 National Oil Shale Assessment. The oil shale zones in descending order are: Bed 76, Bed 44, A Groove, Mahogany Zone, B Groove, R-6, L-5, R-5, L-4, R-4, L-3, R-3, L-2, R-2, L-1, R-1, L-0, and R-0. Each raster cell represents a one-acre square of the land surface and contains values for either oil yield in barrels per acre, gallons per ton, or isopach thickness, in feet, as defined by the grid name: *_b (barrels per acre), *_g (gallons per ton), and *_i (isopach thickness) where "*" can be replaced by the name of the oil shale zone.

ESRI GRID raster datasets were created to display and quantify oil shale resources for eighteen zones in the Uinta Basin, Utah and Colorado as part of a 2010 National Oil Shale Assessment. The oil shale zones in descending order are: Bed 76, Bed 44, A Groove, Mahogany Zone, B Groove, R-6, L-5, R-5, L-4, R-4, L-3, R-3, L-2, R-2, L-1, R-1, L-0, and R-0. Each raster cell represents a one-acre square of the land surface and contains values for either oil yield in barrels per acre, gallons per ton, or isopach thickness, in feet, as defined by the grid name: *_b (barrels per acre), *_g (gallons per ton), and *_i (isopach thickness) where "*" can be replaced by the name of the oil shale zone.

The U.S. Geological Survey (USGS) recently completed a comprehensive assessment of in-place oil in oil shales in the Eocene Green River in the Greater Green River Basin, Wyoming, Colorado, and Utah. A database was compiled that includes about 47,000 Fischer assays from 186 core holes and 240 rotary drill holes. Most of the oil yield data were analyzed by the former U.S. Bureau of Mines oil shale laboratory in Laramie, Wyoming, and some analyses were made by private laboratories. Total in-place resources for the three assessed units in the Green River Formation are: (1) Tipton Shale Member, 362,816 million barrels of oil (MMBO), (2) Wilkins Peak Member, 704,991 MMBO, and (3) LaClede Bed of the Laney Member, 377,184 MMBO, for a total of 1.44 trillion barrels of oil in place. This compares with estimated in-place resources for the Piceance Basin of Colorado of 1.53 trillion barrels and estimated in-place resources for the Uinta Basin of Utah and Colorado of 1.32 trillion barrels. Click here to return to Main Contents

This data release contains the boundaries of assessment units and input data for the assessment of undiscovered gas hydrate resources on the north slope of Alaska. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown herein as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set of known or postulated oil and (or) gas accumulations sharing similar geologic, geographic, and temporal properties within the Total Petroleum System, such as source rock, timing, migration pathways, trapping mechanism, and hydrocarbon type. The Assessment Unit boundary is defined geologically as the limits of the geologic elements that define the Assessment Unit, such as limits of reservoir rock, geologic structures, source rock, and seal lithologies. The only exceptions to this are Assessment Units that border the Federal-State water boundary. In these cases, the Federal-State water boundary forms part of the Assessment Unit boundary. Methodology of assessments are documented in USGS Data Series 547 for continuous assessments (https://pubs.usgs.gov/ds/547) and USGS DDS69-D, Chapter 21 for conventional assessments (https://pubs.usgs.gov/dds/dds-069/dds-069-d/REPORTS/69_D_CH_21.pdf). See supplemental information for a detailed list of files included this data release.

This data release contains the boundaries of assessment units and input data for the assessment of undiscovered gas hydrate resources on the north slope of Alaska. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown herein as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set of known or postulated oil and (or) gas accumulations sharing similar geologic, geographic, and temporal properties within the Total Petroleum System, such as source rock, timing, migration pathways, trapping mechanism, and hydrocarbon type. The Assessment Unit boundary is defined geologically as the limits of the geologic elements that define the Assessment Unit, such as limits of reservoir rock, geologic structures, source rock, and seal lithologies. The only exceptions to this are Assessment Units that border the Federal-State water boundary. In these cases, the Federal-State water boundary forms part of the Assessment Unit boundary. Methodology of assessments are documented in USGS Data Series 547 for continuous assessments (https://pubs.usgs.gov/ds/547) and USGS DDS69-D, Chapter 21 for conventional assessments (https://pubs.usgs.gov/dds/dds-069/dds-069-d/REPORTS/69_D_CH_21.pdf). See supplemental information for a detailed list of files included this data release.

ESRI GRID raster datasets were created to display and quantify oil shale resources for seventeen zones in the Piceance Basin, Colorado as part of a 2009 National Oil Shale Assessment. The oil shale zones in descending order are: Bed 44, A Groove, Mahogany Zone, B Groove, R-6, L-5, R-5, L-4, R-4, L-3, R-3, L-2, R-2, L-1, R-1, L-0, and R-0. Each raster cell represents a one-acre square of the land surface and contains values for either oil yield in barrels per acre, gallons per ton, or isopach thickness, in feet, as defined by the grid name: *_b (barrels per acre), *_g (gallons per ton), and *_i (isopach thickness) where "*" can be replaced by the name of the oil shale zone.

ESRI GRID raster datasets were created to display and quantify oil shale resources for seventeen zones in the Piceance Basin, Colorado as part of a 2009 National Oil Shale Assessment. The oil shale zones in descending order are: Bed 44, A Groove, Mahogany Zone, B Groove, R-6, L-5, R-5, L-4, R-4, L-3, R-3, L-2, R-2, L-1, R-1, L-0, and R-0. Each raster cell represents a one-acre square of the land surface and contains values for either oil yield in barrels per acre, gallons per ton, or isopach thickness, in feet, as defined by the grid name: *_b (barrels per acre), *_g (gallons per ton), and *_i (isopach thickness) where "*" can be replaced by the name of the oil shale zone.