In order to study the fracture propagation morphology of hydraulic fracturing in heterogeneous rock

the random field theory of the center point method was applied to randomize the physical and mechanical parameters of rock. The surface of newly formed fractures was tracked in real time and pressure was applied to simulate the interaction between fracturing fluid and fracture wall. A numerical model for simulating the hydraulic fracturing process of rock was proposed based on the bond-based peridynamics. According to the compression test results of rock containing a prefabricated crack

the effectiveness of the proposed model was verified

the evolution of rock hydraulic fractures was explored considering the effect of the spatial variation direction of rock elastic modulus

fluctuation range of rock elastic modulus

and perforation spacing. When the distribution of rock elastic modulus is layered

the hydraulic fractures tend to propagate along the weak interfaces. When the parameter distribution is directionless

the expansion of hydraulic fractures exhibits strong randomness

and the fracture network tends to become more complex. When the parameter fluctuation range is small

the variability of rock elastic modulus is significant

which caused stress concentration locally

making it easy to form complex fracture structure. A larger parameter fluctuation range leads to homogenization of rock

and the expansion of hydraulic fractures is singular

resulting in a relatively low fracture propagation rate. Under the action of dual perforation

the expansion of fractures in homogeneous rock exhibits a symmetrical distribution. The perforation pressure suppresses the expansion of fractures between the perforations

leading to the main fractures tending to expand towards the boundaries on both sides. And there is a competitive relationship in the expansion of hydraulic fractures in heterogeneous rock. Under the combined effect of stress concentration and material heterogeneity

one hydraulic fracture preferentially expands and then inhibits the development of another one.