摘要：Existing shale gas recovery research highlights effects of in-situ stress condition, temperature and water saturation variations on shale permeability. Conventional laboratory permeability measurement methods are limited with respect to the permeability magnitude range, and thus incapable of accurately determining shale permeability. This paper employs a novel permeability measurement method for shale matrix, namely the gas pulse decay method, to investigate effects of confining pressures, pore pressures, temperatures and water saturations upon shale matrix permeability. Shale gas permeability is found to be negatively related with effective stresses applied onto shale while positively related with temperatures. With identical confining pressures, the test pore pressure of shale core samples grows, as the net confining pressure climbs up, accompanied by decreasing gas permeability reduction ratios. Lower water saturation is demonstrated to enhance gas permeability, and solutions with introduced clean up additives can promote the permeability recovery rate.
