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Chapter 1

Executive Summary
Undiscovered Oil and Gas Resources of
the Uinta-Piceance Province of Utah and
Colorado, 2002

By USGS Uinta-Piceance Assessment Team

Link to Main Contents -Photo:Upper Cretaceous Dakota Sandstone, Westwater Canyon, Utah. (By  P. Lillis, UGSG.

 
 
 

Chapter 1 of
Petroleum Systems and Geologic Assessment of Oil and Gas in the
Uinta-Piceance Province, Utah and Colorado
By USGS Uinta-Piceance Assessment Team

U.S. Geological Survey Digital Data Series DDS-69-B
Version 1.0
2003

 
 
 

U.S. Department of the Interior
Gale A. Norton, Secretary
U.S. Geological Survey
Charles G. Groat, Director

For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225
Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government
Published in the Central Region, Denver, Colorado
Manuscript approved for publication July 24, 2002

ISBN=0-607-99359-6


Contents

Introduction
Resources Assessed
Resource Summary
Uinta-Piceance Province Assessment Team
Reference Cited
Figures
     1. Map showing location of Uinta-Piceance Province in northeastern Utah and northwestern Colorado
     2. Schematic diagram of the types of oil and gas resources assessed in provinces of the United States
Table
     1. Uinta-Piceance Province assessment results.
 
Executive Summary—Assessment of Undiscovered
Oil and Gas Resources of the Uinta-Piceance
Province of Utah and Colorado, 2002
By USGS Uinta-Piceance Assessment Team

Introduction
The U.S. Geological Survey (USGS) recently completed an assessment of the undiscovered oil and gas potential of the Uinta-Piceance Province of northwestern Colorado and northeastern Utah (fig. 1). The assessment of the Uinta-Piceance Province is based on geologic principles and uses the total petroleum system concept. The geologic elements of a total petroleum system include hydrocarbon source rocks (source rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy, petrophysical properties), and hydrocarbon traps (trap formation and timing). Using this geologic framework, the USGS defined five total petroleum systems and 20 assessment units within these total petroleum systems, and quantitatively estimated the undiscovered oil and gas resources within each assessment unit.

Resources Assessed
 For each province in the United States that is to be assessed, the USGS assesses conventional and continuous oil and gas resources (fig. 2). Conventional oil and gas accumulations are defined as having discrete geographic entities with well-delineated hydrocarbon-water contacts. Conventional fields typically have relatively high matrix permeabilities, obvious seals and traps, and high recovery factors. Continuous accumulations (also called

Figure 1. Uinta-Piceance Province in northeastern Utah and northwestern Colorado. Douglas Creek arch separates Piceance

Figure 1. Uinta-Piceance Province in northeastern Utah and northwestern Colorado. Douglas Creek 
arch separates Piceance Basin from Uinta Basin. Wasatch Plateau is included in this province.
 


Figure 2. Schematic diagram of the types of oil and gas resources assessed in provinces of the United States. 

unconventional, tight sandstones, or basin-centered accumulations) are regional in extent; have diffuse boundaries; commonly have low matrix permeabilities; do not have obvious seals and traps, or hydrocarbon-water contacts; are abnormally pressured; are in close proximity to source rocks; and have very low recovery factors (Schenk and Pollastro, 2002). For this study, coalbed gas is considered to be a type of continuous accumulation (Schenk and Pollastro, 2002). Continuous accumulations commonly have transition zones that grade into more conventional accumulations. 

Resource Summary 
The USGS assessed undiscovered conventional and continuous oil and gas, including coalbed gas, in 20 assessment units in five total petroleum systems (table 1). The USGS estimated a mean of about 21 trillion cubic feet of gas (TCFG), a mean of about 59 million barrels of oil (MMBO), and a mean of about 43 million barrels of natural gas liquids (MMBNGL). Nearly all of the undiscovered gas resource is estimated to be in continuous reservoirs rather than in conventional reservoirs. Of the 21 TCFG, 13 TCFG is estimated to be in the Mesaverde Total Petroleum System, and 7 TCFG is in the Mancos/Mowry Total Petroleum System. The Ferron/Wasatch Plateau Total Petroleum System and Mesaverde Total Petroleum System together are estimated to contain 2.3 TCF of coalbed gas. The Phosphoria and Green River Total Petroleum Systems contain the balance of the undiscovered gas resource. Of the total undiscovered oil, about 65 percent is continuous oil in the Green River Total Petroleum System in the deep Uinta Basin; the remainder is oil in conventional accumulations in the Green River and Phosphoria Total Petroleum Systems.

Uinta-Piceance Province Assessment Team
Members of the team, in alphabetical order, are: Larry Anna, Ronald R. Charpentier, Timothy S. Collett, Troy Cook, Robert Crovelli, Russell F. Dubiel, Thomas M. Finn, Mitchell Henry, Robert D. Hettinger, Edward A. Johnson, Ronald C. Johnson, Mark A. Kirschbaum, Timothy R. Klett, Paul G. Lillis, Philip H. Nelson, Vito F. Nuccio, Cynthia A. Rice, Laura N. Roberts, Stephen B. Roberts, Christopher J. Schenk, and J.W. Schmoker.

Reference Cited
Schenk, C.J., and Pollastro, R.M., 2002, Natural gas production in the United States: U.S. Geological Survey Fact Sheet FS-113-01, January 2002. [Also available at URL http://geology.cr.usgs.gov/pub/fact-sheets/fs-0113-01/]
 


 
(This page is best viewed in Internet Explorer or Microsoft Excel)
Table 1. Uinta-Piceance Province assessment results.
[MMBO, million barrels of oil; BCFG, billion cubic feet of gas; MMBNGL, million barrels of natural gas liquids. Results
Results shown are fully risked estimates. For gas fields, all liquids are included under the NGL (natural gas liquids) category
Undiscovered gas resources are the sum of non-associated and associated gas. F95 represents a 95 percent chance of
at least the amount tabulated. Other fractiles are defined similarly. Fractiles are additive under the assumption of perfect
positive correlation. Gray shade indicates not applicable. CBG is coalbed gas.]
Total Petroleum Systems 
(TPS) 
and Assessment Units (AU)
Field Type Total  Undiscovered Resources
Oil (MMBO) Gas (BCFG) NGL (MMBNGL)
F95 F50 F5 Mean F95 F50 F5 Mean F95 F50 F5 Mean
  Phosphoria TPS                      
  Hanging Wall AU Oil  1.75 4.13 8.37 4.47 0.47 1.21 2.67 1.34 0.03 0.07 0.17 0.08
Text Box: Conventional Oil and Gas Resources
  Gas          10.48 24.78 50.27 26.81 0.30 0.78 1.70 0.86
  Paleozoic/Mesozoic AU Oil  2.66 5.82 11.55 6.29 0.71 1.70 3.69 1.89 0.04 0.10 0.23 0.11
  Gas          15.82 43.74 94.30 48.04 0.47 1.36 3.21 1.54
  Ferron/Wasatch Plateau TPS                    
                         
  Ferron Sandstone Gas AU Gas         10.73 35.91 81.23 39.75 0.03 0.07 0.19 0.08
  Mesaverde TPS                  
                         
  Mesaverde Sandstone Gas AU Gas         17.91 58.95 140.12 66.41 0.13 0.46 1.18 0.53
  Green River TPS                    
                         
  Uinta Green River Oil and Gas AU Oil 2.74 9.14 20.52 9.63 7.59 24.83 63.73 28.88 0.42 1.45 3.98 1.73
  Total Conventional
Resources
  7.15 19.09 40.44 20.39 63.71 191.12 436..01 213.12 1.42 4.29 10.66 4.93
Mancos/Mowry TPS                    
                         
  Piceance Basin AU Gas         649.30 1,463.09 3,296.86 1,652.90 0.60 1.43 3.45 1.65
  Uinta Basin AU Gas         1,781.69 2,965.07 4,934.43 3,110.69 3.16 5.81 10.67 6.22
  Uinta-Piceance Transitional
and Migrated Gas AU
Gas         1,429.61 1,742.59 2,124.11 1,755.26 0.74 1.98 5.31 2.37
  Ferron/Wasatch Plateau TPS                  
                         
  Deep (>6000 feet)
Coal and Sandstone AU
Gas         0.00 52.04 136.43 59.10 0.00 0.00 0.00 0.00
Text Box: Continuous Oil and Gas Resources
  Northern Coal Fairway/
Drunkards Wash AU
CBG         451.14 722.18 1,156.05 752.33 0.00 0.00 0.00 0.00
  Central Coal Fairway/
Buzzards Bench AU
CBG         311.61 512.69 843.54 536.73 0.00 0.00 0.00 0.00
  Southern Coal Fairway AU CBG         78.16 145.81 255.49 152.59 0.00 0.00 0.00 0.00
  Southern Coal Outcrop AU CBG         0.00 9.95 30.71 10.56 0.00 0.00 0.00 0.00
  Mesaverde TPS                  
                         
  Uinta Basin Continuous AU Gas         4,134.18 7,018.47 11,915.02 7,391.36 5.52 10.31 19.27 11.09
  Uinta Basin Transitional AU Gas         889.42 1,431.73 2,304.72 1,492.97 1.18 2.10 3.76 2.24
  Piceance Basin Continuous AU Gas         1,902.23 2,956.15 4,594.01 3,064.27 5.00 8.69 15.09 9.19
  Piceance Basin Transitional AU Gas         161.74 284.47 500.33 301.73 0.29 0.56 1.07 0.60
  Uinta Basin Blackhawk
Coalbed Gas AU
CBG         181.97 433.84 1,034.28 498.78 0.00 0.00 0.00 0.00
  Mesaverde Group
Coalbed Gas AU
CBG         138.72 322.45 749.54 367.77 0.00 0.00 0.00 0.00
  Green River TPS                      
                         
  Deep Uinta Overpressured
Continuous Oil AU
Oil  24.83 37.57 56.84 38.78 35.72 60.74 103.29 63.99 2.23 4.17 7.79 4.48
  Total Continuous
Resources
24.83 37.57 56.84 38.78  12,145.49   20,121.27   33,978.81   21,211.03  18.72 35.05 66.41 37.84
                       
                           
Total Undiscovered
Oil and Gas Resources
31.99 56.66 97.28 59.17     12,209.20     20,312.39     34,414.82     21,424.15 20.14 39.34 77.07 42.77
                             

Link to Main Contents -Photo:Upper Cretaceous Dakota Sandstone, Westwater Canyon, Utah. (By  P. Lillis, UGSG.
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US Geological Survey Digital Data Series DDS-69B