Pressure transient analysis for multi-wing fractured wells in dual-permeability hydrocarbon reservoirs

Abstract

Multi-wing and asymmetrical hydraulic fractures around wellbore are usually observed in hydraulic fracturing and refracturing treatments. Therefore, it is significant for us to study pressure transient analysis. In this paper, by employing Laplace transform and finite cosine Fourier transform, a new semi-analytical model was deviated and solved under condition of constant rate for multi-wing fractured wells (MWFWs) of finite conductivity in hydrocarbon reservoirs with dual-permeability behavior in Laplace domain. Stehfest inversion algorithm can be adopted to obtain wellbore pressure of MWFWs in real domain. The solution of the simplified model in this paper was validated with dual porosity dual-permeability and asymmetrical hydraulic fracture, and results reach a good agreement. Type curve, according to pressure derivative characteristic, can be divided into six regimes (bilinear flow, linear flow, radial flow of natural fractures, cross flow and radial flow of system). The influence of some vital parameters (dimensionless conductivity, storage coefficient, crossflow coefficient, permeability ratio et al.) on dimensionless pressure and its derivative curves were analyzed in details. The presented model can be used to understand pressure transient characteristic of MWFWs in hydrocarbon reservoirs with dual-permeability behavior.