Pressure Transient Analysis for Finite Conductivity Multi-staged Fractured Horizontal Well in Fractured-Vuggy Carbonate Reservoirs

Abstract

Transient pressure analysis has been considered as a robust method to identify the flow behaviors, estimate reservoir parameters and hydraulic fracturing parameters. Compared with conventional clastic reservoirs, complex pore systems in fractured–vuggy carbonate reservoirs are posing significant research challenges. Although pressure transient analysis(PTA) models for different style wells in carbonate reservoirs have been widely studied, limited study has been conducted for multi-fractured horizontal well (MFHW) in these reservoirs. Thus, this paper is an investigation on PTA for MFHW of fractured-vuggy carbonate reservoirs. Based on source function theory, mirrors reflection and superposition principle,, the finite conductive MFHW’s bottom-hole pressure solution for fractured-vuggy carbonate reservoirs is obtained by the Laplace transform and the Stehfest inversion method. Log-log type curves are drawn by numerical algorithms and eight flow regimes are identified. Finally the influences of sensitivity parameters such as fracture number, fracture spacing, half length of fracture, storativity ratio, inter-porosity flow coefficient on unsteady flow behaviors of MFHW are discussed in depth.