Numerical analysis of retrograde gas behavior in fissured systems: The single-block model

This article presents the description of depletion behavior of retrograde gases when stored in naturally fractured systems. The present study focuses on the preliminary understanding of condensate build-up within the matrix at saturations below critical, with special emphasis on the limiting cases where flow hindrance due to the presence of the condensate might be exacerbated. The entire fissured reservoir is depicted as a stack of several single blocks of matrix rock, where ultimate recovery is controlled by the behavior of each of the single-matrix blocks in the stack. A fully implicit, in-house compositional model that tracks the condensate build-up in the single block and allows the description of its impact on system behavior is presented. This work centers around the betterment of our understanding of the phenomena taking place within a single-matrix block, as the single most important building block needed for the understanding of behavior of fissured systems hosting gas condensates.