Pressure Transient Analysis of Vertically Fractured Multi-well System

The mathematical model of transient flow considering threshold pressure gradient in vertically fractured multi-well system of reservoir with arbitrary shape is developed and solved by using finite element method. And the behavior of the bottomhole pressure varying with time is obtained. Then wellbore storage coefficient and skin factor are introduced by means of Laplace Transformation and Stethfest Inversion. In this paper, calculation of fractured multi-well system is made by taking the element of rectangular well pattern in a closed circular reservoir as an example, and pressure transient curves are drawn. The curve characteristics are analyzed, along with the influences of property and productivity in adjacent wells, injection-production ratio and pattern, and fracture conductivity on pressure transient curve. The study shows that the testing data of production wells are easily influenced by adjacent wells in the test later. Using vertically fractured multi-well system model to interpret well test data can eliminate the interferences to a large extent, and improve the utilization and effect of well test data.