Pressure transient behavior of multiwell interference in strip-shaped heterogeneous reservoirs

Abstract

Fault-karst reservoirs are commonly observed as strip-shaped characteristic. Due to the strong heterogeneity of fault-karst reservoir, the production well is often affected by the simultaneous interference from multiple wells. However, multiwell interference well testing without shut-in becomes popular for the purpose of continuous production, there are few related models that are able to analyze fault-karst reservoirs. This paper derives a novel multiwell interference analytical model based on Darcy flow in the strip-shaped heterogeneous reservoir. The accuracy of this bottom-hole pressure (BHP) solution is verified by comparing with numerical simulation results. Then the effect of interference’s distance and intensity on BHP are investigated. The results show that pressure and its derivative curves can diagnose the interference flow regimes. The timing of interference occurrence is determined by the formation transmissibility, storability and well distance. Also, the characteristic of the type curve is related with the production of interfering wells. This work provides technical support for accurately capturing interference effect and gives a comprehensive workflow for rapidly diagnosing the multi-well interference by analyzing BHP data.