页岩气储层压裂数值模拟技术研究进展

页岩气储层水力压裂数值模拟既要考虑页岩储层岩石的特性,又要兼顾水平外分段压裂施工工艺,是一个非常棘手的力学难题.本文简述了页岩气储层岩石具有的地质力学特征和页岩气储层开发常用的水平井分段压裂技术;详述了扩展有限元、边界元、离散元在水力压裂裂缝模拟上的应用现状,指出了它们在处理裂缝问题的局限性和优越性,总结出边界元三维位移不连续法是模拟多裂缝扩展的有效方法.

A REVIEW OF NUMERICAL SIMULATIONS OF HYDRO-FRACKING IN SHALE GAS RESERVOIR

In the numerical simulation of hydraulic fracturing in a shale gas reservoir, both the shale rock's properties and the multistage hydro-fracking technique of the horizontal well should be considered, which is a difficult problem of mechanics. In this paper, the mechanical characteristics of the shale rock and the multistage fracking technology of the horizontal well in the shale gas reservoir are discussed, as well as the applications of the extended finite element method, the boundary element method and the discrete element method in hydraulic fracturing and their advantages and limitations. It is indicated that the three dimensional displacement discontinuity method of the boundary element method is an effective approach to model the propagation of multistage fractures.