1995 National Oil and Gas Assessment and Onshore Federal Lands
Donald L. Gautier, Gordon L. Dolton and Emil D. Attanasi

U. S. Geological Survey Open-File Report 95-75-N
January 1998

FEDERAL ONSHORE OIL AND GAS RESOURCES

Technically recoverable oil and gas resources

Table 3 shows the regional estimates of technically recoverable oil and gas for onshore Federal Lands by resource category. Companion tables at the province level are provided in Appendix A. Table A-2 shows corrected estimates of technically recoverable undiscovered conventional oil and gas for the US onshore and State offshore areas by province (Gautier and others, 1996). Table A-3 shows estimates of undiscovered conventional oil and gas for onshore Federal Lands by province. Figure 3 and Figure 4 show the relative magnitudes of the technically recoverable resources of oil and gas by region and resource category. Similarly, Tables A-4 and A-5 show estimates of technically recoverable resources of continuous-type accumulations and coalbed gas located on onshore Federal Lands. About 85 percent of the technically recoverable gas in undiscovered conventional fields is non-associated gas, that is gas in gas fields. Overall, about 29 percent of US onshore land area is Federally owned and, at the mean level, about 25 and 22 percent of the undiscovered conventional oil and gas assessed in the 1995 National Assessment were assigned to Federal Lands. The Northern Alaska province accounts for almost half of the oil and more than half of the undiscovered conventional gas assessed on onshore Federal Lands. The Powder River basin (33) and the Wyoming Thrust Belt (36) provinces of the Rocky Mountains and Northern Great Plains Region have the next largest concentrations of undiscovered conventional oil and gas, respectively, assessed on Federal Lands.

Assessed continuous-type resources and coalbed gas were confined to the lower 48 States. Amounts of oil in continuous-type accumulations on Federal Lands are small. Federal Lands did, however, account for 41 percent of the total gas in continuous-type accumulations and 32 percent of the total coalbed gas assessed in the 1995 National Assessment. The Rocky Mountains and Northern Great Plains Region, principally Southwest Wyoming province (37), has the largest assessed quantity of technically recoverable gas in continuous-type accumulations on Federal Lands (Table A-4). The Colorado Plateau and Basin and Range Region (Uinta-Piceance Basin, province 20, and San Juan Basin, province 22) had by far the largest assessed quantity of coalbed gas on Federal Lands (Table A-5). For all onshore Federal Lands, gas assessed in continuous-type accumulations represents more than twice the gas in undiscovered conventional fields (Tables A-3, A-4).

Economically recoverable oil and gas resources

Table 4 shows regional mean values of technically recoverable quantities of oil, gas, and natural gas liquids in conventional undiscovered accumulations, continuous-type accumulations, and coalbed gas accumulations along with economic quantities having incremental costs of $18 per barrel or $2 per mcf and $30 per barrel or $3.34 per mcf. Figures 3 and 4 depict the regional estimates of oil and total gas by sources. Because of an absence of markets, for the 1995 Assessment it was assumed that gas in Northern Alaska would not be economic. At $18 per barrel and $2 per mcf only about 20 percent of the technically recoverable undiscovered conventional oil and 17 percent of the technically recoverable undiscovered gas is economic to find, develop, and produce on Federal Lands. This compares to 30 percent for onshore oil and 24 percent for onshore gas on all lands (Attanasi, 1996). This results because regions having lowest cost conventional oil and gas resources, that is, West Texas and Eastern New Mexico (Region 5) and the Gulf Coast (Region 6) (see Attanasi, 1996) have little Federal Land. Approximately two-thirds of the economic gas is non-associated gas. Table A-3 shows economic undiscovered conventional oil on Federal Lands distributed more or less evenly among several provinces but undiscovered conventional gas concentrated principally in the Wyoming Thrust Belt province (36) and in the Uinta-Piceance province (20).

At $2 and $3.34 per mcf, only 6 and 11 TCF (5 and 9 percent) of the more than 127 TCF assessed mean technically recoverable gas in continuous-type accumulations is economic. Nearly all of the economic gas at $2 per mcf is from the San Juan Basin province (22) and Uinta-Piceance Basin province (20) of the Colorado Plateau and Basin and Range region and the North-Central Montana Province (28) of the Rocky Mountains and Northern Great Plains region. As incremental costs are allowed to increase to $3.34 per mcf, additional gas becomes economic in the Uinta-Piceance and San Juan basins and a tiny part of the large quantity of assessed technically recoverable gas in the Southwestern Wyoming province (37) is added.

The economic component of the 1995 National Assessment showed that the lowest cost coalbed gas resources are in the Uinta-Piceance and San Juan Basins. Three-fourths of the assessed technically recoverable coalbed gas resources of the Uinta-Piceance Basin and half of the coalbed gas resources of the San Juan Basin were assigned to Federal Lands. At $2 per mcf, 43 percent of the assessed coalbed gas is economic and, at $3.34 per mcf, 73 percent of the assessed Federal Land coalbed gas is economic.

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