关键词: 水力压裂, 水平集法, 弥散裂缝模型, 非均质岩石, 流-固耦合

Abstract: The level set method(LSM)was introduced to describe the static material interface in a rock material. The finite element modeling procedures for the three-dimensional rock sample with the layered feature， randomly distributed inclusions and statistical Weibull distribution heterogeneity were given via the LSM. To study the propagation of hydraulic fracture， a smeared crack model based on the fully coupled， elasto-plastic， pore pressure-solid phase interaction theory was coupled to the LSM. The Corey relation and relative permeability were adopted to calculate the viscosity and permeability of mixture in the smeared cracked hydraulic fracture model. Finally， a case study that simulating hydraulic fracture propagation was carried out in a heterogeneous rock sample following Weibull distribution. The development of equivalent crack zone， pore pressure versus injection time and the effective stress path in the injected element were discussed. The simulation results indicate that the LSM coupling with smeared crack model can be well used for modeling the heterogeneity of three-dimensional rock material and simulating the hydraulic fracturing.

Key words: hydraulic fracturing, level set method(LSM), smeared crack model, heterogeneous rock, fluid-solid coupling