A New Approach to Calculate Effective Stimulated Reservoir Volume in Shale Gas Reservoir

Hydraulic fracturing practices in shale reservoirs show that effective stimulated reservoir volume (ESRV) significantly affects the production of hydraulic fractured well. Therefore, estimating ESRV is an important prerequisite for the evaluation and production prediction of hydraulic fracturing wells in shale reservoirs. This paper introduces a representation elementary volume (REV) of orthogonal discrete fracture coupled dual-porosity matrixflow model to predict the volumetric flux of gas in shale reservoirs. The influence of fracture space and fracture width on gas migration was studied. Considering fractal characteristics of the fracture network in stimulated reservoir volume (SRV), fractal dimension was used to quantitatively evaluate the fracture space distribution. Combining the effective fracture space and fractal characteristic of fracture network, a new approach was proposed to evaluate the ESRV in shale reservoirs. The approach was used in Eagle Ford shale gas reservoir and the results show that the fracture space has a great influence on migration of adsorbed gas. Fracture network has a contribution to enhance absorbed and free gas recovery ratio when the fracture space is less than 0. 20 m. The ESRV was evaluated in this paper and the results indicate that the ESRV accounts for 37. 78% of the total SRV in shale gas reservoir. The ESRV was influenced by both secondary fracture distribution and effective fracture space, as a result of reservoir intrinsic property and hydraulic fracturing practices. © 2017, Editorial Department of Earth Science. All right reserved.