Linear and Radial Flow Targets for Characterizing Downhole Flow in Perforations

Abstract

Summary Two types of sandstone targets are commonly used to test flow efficiency of shaped-charge jet perforations: "linear" targets, in which flow enters only the unperforated end of the cylindrical sample, and "radial" targets, in which flow enters through the end and sides of the sample. To determine which of these targets best represents downhole conditions, the flow distribution along the length of a perforation has been studied by three-dimensional (3D) finite-element analyses. Linear and radial laboratory targets have been compared with downhole perforations under varying conditions. For ideal perforations, the low-shot-density (LSD) case is adequately represented by the radial target, while the high-shot-density (HSD) case falls between the two targets. With realistic crushed and damaged zones, the HSD case closely matches the linear target, and the LSD case falls between the two targets.