Numerical simulation of abrasive water jet impacting porous rock based on SPH method

Shale contains pores. The abrasive water jet technology is used to extract oil and gas resources inside the shale, and the impact process is affected by the pores. For the damage process of abrasive water jet impacting the pore-containing rock, according to the basic principle of smoothed particle hydrodynamics (SPH) method, the abrasive water jet and the pore-containing rock are discretized into a series of particles, and a dynamic model for the abrasive water jet impacting the pore-containing rock is established by the constitutive relationship of NULL and H-J-C to describe the mechanical properties of abrasive water jets and rock respectively. The effectiveness of the established model is verified and analyzed by simulating the impact of abrasive water jet on the rock and comparing with the existing research results. On this basis, the dynamic damage process of the abrasive water jet impacting the pore-bearing rock is simulated, and the effects of pore characteristics and jet parameters on the damage degree of rock are also analyzed. The simulated results show that the velocity of abrasive water jet and porosity of rock have significant effects on the breaking process of the rock, while the size and distribution of the pores can affect the breaking shape of the rock, and other factors have different influences on the damage degree of rock. The research conclusion can provide theoretical support for improving the rock-breaking efficiency of water jet in engineering.