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Study indicates unconventional gas reserves up dramatically USGS reports on Rocky Mountain basins, will look at Alaska; goal is to see if U.S. can produce 30-36 tcf by the year 2020 Gary Park PNA Canadian Correspondent
Dramatic gains in unconventional natural gas reserves in the United States’ Rocky Mountain region have been reported by the United States Geological Survey.
In its 2002 assessment released Dec. 18, the USGS estimated undiscovered gas in the five geologic basins of the Rocky Mountains at 183 trillion cubic feet, of which 169 trillion cubic feet was listed as unconventional, including 42 trillion cubic feet of coalbed methane.
Chris Schenk, a USGS geologist who led the assessment, said the overall goal was to answer the question: Can the U.S. resource base sustain a production capacity of 30 to 36 trillion cubic feet of gas by the year 2020?
He said the USGS intends, over the next several years, to perform resource assessments of the entire United States, including Alaska, but excluding federal waters.
Estimates by basin The 2002 mean estimates for natural gas, oil and natural gas liquids are:
Uinta-Piceance (Colorado and Utah): 21 trillion cubic feet, 60 million barrels of oil and 43 million barrels of NGLs. Nearly all the undiscovered gas resource is unconventional.
Southwestern Wyoming (Greater Green River Basin): 84.6 trillion cubic feet, 131 million barrels of oil, 2.6 billion barrels of NGLs. Most of the undiscovered gas resource is unconventional.
San Juan Basin: 50.6 trillion cubic feet, 19 million barrels of oil, 148 million barrels of NGLs. Nearly all the undiscovered gas resource is unconventional.
Montana Thrust Belt: 8.6 trillion cubic feet, 109 million barrels of oil, 240 million barrels of NGLs. All the undiscovered gas resource is conventional.
Power River (Wyoming and Montana): 16.5 trillion cubic feet, 1.6 billion barrels of oil, 86.5 million barrels of NGLs. Most of the undiscovered gas resource is unconventional.
Coalbed methane reserves in the San Juan Basin of Mexico and Colorado soared to 24 trillion cubic feet from the 7 trillion cubic feet contained in a 1995 assessment, while Power River’s CBM reserves rose to 14.3 trillion cubic feet from 1.1 trillion cubic feet.
Information from exploration, drilling The gains were based on new geologic information derived from increased exploration and drilling.
The assessment criteria describe conventional resource accumulations as discrete fields with well-defined water contacts, obvious seals and traps and hydrocarbon is buoyant upon a column of water.
Unconventional accumulations are regional in extent, have diffuse boundaries, do not have obvious seals and traps and are not buoyant upon a water column.
The USGS said in a statement that its findings are a sign that unconventional resources contribute more than conventional resources in the five basins covered by the study.
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