Numerical Simulation of the Interaction between Hydraulic Fracture and Natural Fracture Using the Extended Peridynamic Model

For oil and gas exploitation engineering, it is significant to study the interaction between hydraulic fracture (HF) and natural fracture (NF). An extended peridynamic (PD) model for hydraulic fracture analysis is presented, in which the PD pairwise force with the bond rotation is considered, fluid pressure is applied at fracture surfaces with broken bonds, and the critical stretch and critical relative rotation bond failure criteria are derived for Mode I and Mode II fractures of shale reservoir, respectively. Then, numerical examples of hydraulic fracturing of concrete and shale are analyzed using the PD model. The proposed model can well predict the interaction behaviors between HF and NF, and simulation results show that the larger the in situ stress difference and approach angle, the easier it is for the hydraulic fractures to cross the natural fractures.