Numerical Simulation on the Interaction Modes Between Hydraulic and Natural Fractures Based on a New SPH Method

In order to study the interaction mechanisms between hydraulic fractures (HF) and natural fractures (NF), a new numerical method named 2P-IKSPH has been proposed. The interactions between HF and NF under different conditions are simulated, results show that under the condition of low vertical confining pressure and low injecting rate, NF initiates at one tip closer to the horizontal boundary; under the condition of high vertical confining pressure, high injecting rate and small inclination angle of NF, the branching phenomenon occurs. The confining pressure, inclination angle and injecting rate all have significant impacts on the characteristic loads (e.g., HF initiation pressure, approaching pressure and NF initiation pressure). The research results can provide some references for the understanding of interaction mechanisms between HF and NF; meanwhile, developing high performance 3D 2P-IKSPH program will be the future research directions.