GEOTECHNICAL CONSIDERATIONS IN UNDERGROUND COAL GASIFICATION.

Field tests of underground coal gasification in steeply dipping beds were conducted in the North Knobs area, located 12. 8 km (8 miles) west of Rawlins, WY. A geotechnical program was essential to complete the test program. Emphasis of the program was the subsurface characterization of the site and consisted of mapping, drilling and logging, core analyses, and hydrologic tests. The samples of lithologic units over- and underlying the G coal seam were tested in the laboratory for their modulus and strength. This program provided the required data necessary for designing surface facilities, input for permits, and correct placement of the process modules.