HYDROGEOLOGICAL TESTING ASSOCIATED WITH UNDERGROUND COAL-GASIFICATION

Four aquifer tests were completed at a site near Forestburg, Alberta, Canada, to determine aquifer parameters of a coal seam and thus aid in the evlauation of an underground gasification experiment and assess the effects of gasification on the groundwater regime. Analysis of the two pre-gasification aquifer tets indicated that the coal seam was a confined aquifer with small aquifer parameters and a strongly anisotropic hydraulic conductivity that appeared unrelated to known regional fracturing directions. The effect of this anisotropy on controlling directions of gasification was not established. The first post-gasification aquifer test indicated that the groundwater regime of the coal seam had been changed in various ways. The second post-gasification aquifer test indicated that fracturing in the coal seam was not consistent and that in undisturbed coal seams the direction of regional major fracturing and the major axis of anisotropy do, in fact, coincide. Refs.