Determination of Reservoir Permeability Distributions from Pressure Buildup Data

Abstract

Abstract This work focuses on the analysis of pressure buildup data obtained at a well at the center of a cylindrical reservoir in which the absolute permeability is a function of distance from the well, i.e., is a function of the radial coordinate. It is shown that the permeability distribution can be estimated directly from pressure buildup data by application of an inverse solution algorithm. For cases where permeability is a function of both r and θ, it is shown that our inverse solution procedure yields an "equivalent" radial permeability distribution. It is also shown that the reservoir pressure profile at the instant of shut-in can be approximated from the buildup pressure data. Finally, we discuss briefly, the stabilized inflow performance relations for a well producing from the center of a cylindrical heterogeneous reservoir.