Pressure and Pressure Derivative of a Horizontal Well Subjected to a Single Edge and Bottom Water Drive Mechanism

Abstract

A horizontal well test analysis is complicated and difficult to decipher. Most mathematical models for horizontal wells assume that they are completely horizontal and parallel to the reservoir's top and bottom borders. The goal of this study is to develop a mathematical model for a horizontal well completed in an oil reservoir at late time flow period for isotropic reservoirs, where the reservoir is bounded by an edge and bottom constant pressure boundaries for the interpretation of pressure responses, as part of an effort towards correct horizontal well test analysis.Using reservoir and well parameters, Excel software was used to investigate which set of reservoir and well parameters would prolong productivity before steady state set in. The higher the well productivity and the longer it takes to reach steady state, the greater the distance between the well and the x and z-boundaries (constantpressure boundaries).Dimensionless pressure rises as reservoir pay thickness increases, delaying steady-state conditions. When the well length is short, as in this investigation, the dimensionless lateral extent has no direct effect on the dimensionless pressure and derivative. As a result, the distance from the constant pressure boundary, well length, and pay thickness are the most important factors in determining external fluid inversion in the wellbore.