Performance evaluation of multiple fractured horizontal wells in shale gas reservoirs

Abstract With the rapid development of hydraulic fracturing technology, shale gas has become a significant natural gas resource in China. At present, SRV (stimulated reservoir volume) fracturing technology is widely used to exploit shale gas reservoirs. To evaluate the shale gas reserves and design a development plan, a simple and rapid method is needed to predict the production and performance of the multistage fractured horizontal wells with stimulated reservoir volume in shale gas reservoirs. Network fractures with different lengths and widths are not symmetrical to the horizontal well. To account for the complexity of the fracture system and desorption characteristics of shale gas, a semianalytical multiregion seepage model has been established to analyze the performance of multiple fractured horizontal wells. In this paper, a triple‐porosity dual‐permeability model is developed for simulating the flow mechanism of shale gas. Different lengths and widths of network fractures, different fracture intervals, and asymmetry distribution are considered in this model. By employing the principle of Poisson's superposition and Bessel transformation, the fundamental solution of instantaneous point source function has been derived to calculate the pressure response of each hydraulic fracture. Then, the mathematical model for unsteady performance evaluation in multiple fractured horizontal wells has been obtained to simultaneously solve the pressure response of every hydraulic fracture. The sensitivity analysis in terms of the lengths and widths of network fractures, fracture intervals, and the asymmetry distribution of a complex fracture system is presented. The research results show that the SRV morphology will exert a great influence on the performance of multiple fractured horizontal wells.