Pressure behavior of multi-stage fractured horizontal well in a laterally non-uniform reservoir

Abstract

Formation heterogeneity is very common in practice, where the reservoir usually consists of several regions with dissimilar properties separated by discontinuities. Because of the effect of the heterogeneity, there are few literatures studying the pressure response of multi-stage fractured horizontal (MSFH) wells in a laterally non-uniform reservoir. In this work, considering the linearity of the governing equations for describing fluid flows, the Laplace-domain point-source solution for three-region linear composite reservoirs is derived, based on which seepage model for an MSFH well in a laterally non-uniform reservoir is established. Fracture discrete scheme and Stehfest algorithm are used to solve the established model for an MSFH well. The validation of the proposed model is conducted by comparing with the simplified semi-analytical models in literatures and the commercial numerical simulator, which shows that our results match well with both analytical results and numerical results. Pressure behavior of an MSFH well in laterally non-uniform reservoirs is analyzed thoroughly based on the proposed model. It is found that the pressure behavior is significantly influenced by formation heterogeneity, well location, and well properties. The study provides a point-source function method for calculating pressure solutions of MSFH wells in three-region linear composite reservoirs, which can be easily extended to other complex well types besides MSFH wells, such as MSFH wells with stimulated reservoir volume, and fractured vertical wells with multiple fracture wings.