The Performance of Perforated Completions in Gas Reservoirs

Abstract

Summary A finite-element program was used to study the influence of shot density, perforation length, phasing angle, formation permeability, formation anisotropy, and turbulence factor on the performance of perforated completions in gas reservoirs. The results indicate that when permeability is low (< 10 md), turbulence effects are negligible, and perforation length and phasing angle affect productivity ratio. In anisotropic formations, high shot density (≥ 12 shots/ft [39 shots/m]) with deep penetration (≤ 15 in. [38 cm]) is required for the well to perform better than an openhole completion. Turbulence effects can cause up to 75% loss in production in high-permeability formations. The nomograph presented can be used to predict productivity ratios and skin factors in gas reservoirs.