Vertical and lateral variation of gas content associated with coal seams

Abstract

Vertical and lateral gas content variation associated within a coal seam and its relation to porosity and geology was researched. Several seams of high sub-bituminous and bituminous coal volatile C from Amaga formation were selected. Channel samples were taken and were subdivided into the different plies (lithotypes associations), performing proximal analysis; Petrographic (maceral counting and determining the vitrinite reflectance); furthermore desorption testing and porosity. The higher gas content was in intermediate plies. It was possible to identify that the gas content, and micropores and mesopores has a direct relationship; also, there is a direct relationship between the content of liptinites macerals and gas content. In some cases, these relationships were not clear, since there is influence of geological factors such as the presence of faults favor migration and degassing of the mantles studied.