--> Coal and Coalbed Methane Resources of the Sego Coal Field, Eastern Utah, by D. E. Tabet; #90986 (1994).

Datapages, Inc.Print this page

Abstract: Coal and Coalbed Methane Resources of the Sego Coal Field, Eastern Utah

David E. Tabet

A new coal and coalbed methane resource assessment of the Sego coal field in eastern Utah was prepared using coal-thickness data compiled from oil and gas wells along with published coal-thickness, methane-cont and vitrinite-reflectance data. These data were compiled on maps at a scale of 1:100,000.

The Sego field coal is in the Upper Cretaceous (Campanian) Neslen Formation of the Mesaverde Group. This 250- to 450-foot-thick formation has four to five relatively persistent coal zones. Each zone contains to four lenticular coal beds which vary in thickness from a feather edge to 15.0 feet within a couple miles. Each zone usually contains 1 to 4 feet of coal. The total aggregate coal thickness in the Neslen Formation ranges from 0 to 23.2 feet. The coal is generally best developed in the upper Neslen zones along the southeastern margin of the field where the coal crops out.

Vitrinite-reflectance data for the Neslen coals, ranging from 0.62 to 0.84 percent, show these coals increase in rank with depth and have reached the rank where methane generation begins. Six Sego field wells have been sampled for coal gas content, and all samples tested were from depths of less than 865 feet. Data from four of the holes show trends of increasing gas content with depth which predict coal-gas contents of 68 to cubic feet per ton at a depth of 1,000 feet. Potential gas resources in Sego field coal were estimated multiplying the predicted gas-content estimates by new coal resource figures for areas where total Neslen Formation coal is greater than 10 feet thick and deeper than 1,000 feet.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994