Semianalytical method of two-phase liquid transport in shale reservoirs and its application in fracture characterization

This study presents a new semi-analytical method to simulate the two-phase liquid transport in hydraulic fractures (HF) and matrix system, which can be applied to characterize HF attributes and dynamics using the flowback data from hydraulically fractured shale oil wells. The proposed approach includes a fracture model for HF properties calculation and a matrix model capable of considering multiple liquid transport mechanisms in shale nanopores. The proposed method is first validated with the numerical simulation then applied to a field example in Eagle Ford shale. The numerical validation confirms that our method can accurately characterize fracture attributes and closure dynamics by closely estimating the initial fracture permeability, pore-volume, compressibility, and permeability modulus. Furthermore, the analysis results from numerical simulation and a field example both indicate a clear flow enhancement and deficit for oil and water transport, respectively, due to the slippage effect and variation of fluid properties inside nanopores.