Pressure Transient Behavior of a Finite-Conductivity Fractured Well with Spatially Varying Fracture Properties

Abstract

Abstract The pressure transient behavior of a finite-conductivity vertically fractured weil is important in reservoir engineering because it provides valuable information concerning the well completion, and provides estimates of the in-situ reservoir properties and the propped fracture dimensions and conductivity. The pressure transient behavior of finite-conductivity fractured wells has typically been analyzed using mathematical models that assume relatively simple fracture properties. Most of these models assume uniform fracture height, width, and proppant permeability distributions with respect to space, and many of these models also assume that fracture storage effects are negligible. This paper presents the pressure transient solution of a well intersected by a finite-conductivity vertical fracture with a lengthwise variation in the fracture geometric and material properties. The general solution of the fracture fluid-flow problem, and an approximate solution of the problem in which the effect of fracture storage has been assumed to be negligible, are presented. Comparisons of the pressure transient behavior predicted with the two finite-conductivity fracture solutions are given. The effects of spatially varying fracture height, width, and material properties are investigated with these pressure transient solutions. The new solutions provide more realistic pressure transient analysis models which may be used to better design, implement, and evaluate hydraulic fracture treatments. They will also provide better agreement between the prediction of the fracture geometry and its post-treatment evaluation.