Pressure-transient analysis in shale gas reservoirs: A review

The characteristics of shale formations are different from other typical sedimentary formations. They are stress-sensitive rocks with contained fluids subject to rapid adsorption and desorption activities. Importantly, the flow of fluids in shale reservoirs is pressure-dependent and of a non-Darcy nature. For these reasons, the typical pressure-transient analyses are not applicable to these low-permeability reservoirs. Although several modifications to conventional analyses have been proposed, there are still a number of gaps in the proper characterization of shale gas and oil reservoirs. In this research, we reviewed the literature on pressure-transient analysis in shale reservoirs, presented the limitations of the proposed methods, and suggested future research directions for improved interpretation of transient pressure data.