Development and Evaluation of Near-Mine Stimulation Techniques for Coalbed Degasification

摘要

The purpose of this project was to determine the effects of foam stimulation treatments upon mining conditions in underground coal mines. Underground investigations were conducted to characterize the geological and mining conditions both before and after the holes were stimulated. Of 12 holes that were drilled at mine sites in Kentucky, Pennsylvania, Utah, and West Virginia, 4 were mined through and mining progressed within 75 ft of a fifth before mining plans were altered because of unassociated reasons. The fracture fluids were tagged with fluorescing paint pigments to enable their underground pathways to be detected with an ultraviolet light and accurately mapped. At the holes that were intercepted by mining, the induced fractures were all contained within the coal seams. Horizontal fracturing at the seam-roof interface and along an in-seam binder was more extensive than the vertical fracturing, which was confined primarily to the more friable portion of the seam.