页岩气藏复杂缝网扩展流固耦合数值模拟研究
Study on the Numerical Simulation of Hydro-Mechanical Coupling of Complex Fracture Network Propagation in Shale Gas Reservoirs

页岩气藏主要依靠水力压裂技术进行商业开发，准确预测页岩气藏压裂缝网扩展，对压裂方案优化设计以及压后产能计算具有重要意义。本文在考虑流固耦合效应的基础上，建立了页岩气藏复杂缝网扩展数学模型，采用有限元方法和有限体积方法对应力场和压力场进行了离散求解。通过与KGD模型解析解对比，验证了模型和算法的准确性，进而分析了水平应力差和射孔簇数对缝网形态的影响，阐述了页岩气藏缝网扩展规律，对页岩气藏压裂优化设计具有指导意义。
The commercial development of shale gas reservoirs mainly depends on hydraulic fracturing technology. Accurate prediction of fracture network propagation in shale gas reservoirs is of great significance for the optimization design of fracturing schemes and the calculation of post-fracturing productivity. In this paper, considering the hydro-mechanical coupling effect, the mathematical model of complex fracture network propagation in shale gas reservoirs is established, and the finite element method and finite volume method are used to discretize the stress field and pressure field. The accuracy of the model and algorithm is verified by comparing them with the analytical solution of the KGD model, and then the influence of horizontal stress difference and perforation cluster number on the fracture pattern is analyzed, and the fracture network propagation law in shale gas reservoirs is expounded, which has significance for guiding the optimal design of fracturing in shale gas reservoirs.