Pressure transient behavior analysis in a dual-porosity reservoir with partially communicating faults

• We model the effect of PCF on transient pressure behavior.
• Analytical solutions for pressure transient behavior are obtained.
• The boundary skin of fault affected the slope of derivative pressure curve.
• λ affects the time when the dip of derivative curve appears.

Many oil bearing fractured reservoirs are faulted reservoir (Abbaszadeh M.D. and Cinco-Ley H., 1995). Hydraulic characterization of these faults is essential for field-scale development design. In this study, a mathematical model is presented that describes the pressure transient behavior of a reservoir separated by a partially communicating fault (PCF). In the math model, vertical well is treated as an infinite line source; and PCF is treated as an infinitely long, vertical semi-permeable barrier. Based on the Warren Root model, transient pressure model of a two-region-infinite-composite dual-porosity reservoir with PCF has been established. Two regions on both sides of the fault have distinct properties. Given a line source, constant-rate well in a composite reservoir, analytical solutions of pressure transient behavior are obtained using one Fourier space transformation and time-space Laplace transformation. In addition, derived type curves and sensitivities of relating parameters are discussed. Model presented in this paper could be directly applied for well test analysis in a dual-porosity reservoir with PCF.