Performance of Perforated Completions in the Presence of Anisotropy, Laminations, or Natural Fractures

Abstract

Summary Finite-element method (FEM) was used to evaluate the steady-state flow response of the near-wellbore region in the presence of anisotropy, shale laminations, and natural fractures. The relative importance of various geometric perforation parameters under such conditions was also examined. The study indicated that completion efficiency is strongly influenced by common heterogeneities. The variation in productivity is substantial and emphasizes the importance of including a good description of the formation heterogeneities in the design and evaluation of a perforating program. The best description is derived by use of data from all available sources (cores, well tests, and logs). The principal findings of this study were (1) that high shot densities are needed in anisotropic and laminated formations, (2) that the performance of perforated completions varies with the type, orientation, and density of the natural fractures, (3) that different geometric parameters assume different significances for different types of fracture networks, and (4) that a sound fracture detection and evaluation program is essential for the proper design and evaluation of the perforated completion in such an environment. The results presented can be used to design and to evaluate perforated completions in naturally fractured environments.