Abstract
The purpose of this project was to determine the effects of foam stimulation treatments on mining conditions in underground coal mines. Underground investigations were conducted to characterize the geological and mining conditions both before and after tee holes were stimulated. Of 12 holes that were drilled at minesites 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 inseam binder was more extensive than the vertical fracturing, which was confined primarily to the more friable portion of the seam. The mining conditions, roof, floor, and support requirements were unaffected by the stimulation treatments.
