Shale gas reservoirs have been observed to exhibit a half slope on a log-log plot of rate against time. This indicates transient linear behavior and is believed to be caused by drainage from matrix surfaces into the adjoining fractures.
A standard test case for the slab matrix transient dual porosity model is presented in this paper. It is shown in this paper that various shape factor formulations can be used in the transient dual porosity model provided that corresponding appropriate changes are made in the solution parameters and the interporosity flow parameter. It is also shown in this paper that different matrix geometry exhibit the same transient linear response when the area-volume ratios are similar.
This paper also presents a procedure incorporating a rectangular geometry dual porosity model to analyze the transient linear flow regime obtained in naturally fractured shale gas reservoirs. This procedure allows the use of different matrix geometries.