Determining the Source of Longwall Gob Gas Lower Kittanning Coalbed, Cambria County, PA

William P. Diamond, James P. Ulery, Stephen J. Kravits — 1992

Four coreholes were drilled (two before and two after mining) at a longwall mine to obtain coal and rock samples from overlying strata to determine their gas content at various times in the mining cycle. Test results indicate that 91 pct of the gas removed from the overlying strata came from coalbeds.