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.

为了研究水力压裂与自然压裂之间的相互作用机理，提出了一种新的数值方法2P-IKSPH。模拟了HF和NF在不同条件下的相互作用，结果表明，在低垂直围压和低注入速率的条件下，NF起始于靠近水平边界的一端。在垂直围压高，注入速率高，NF倾角小的条件下，会发生分支现象。围压，倾斜角度和注入速率均对特征载荷（例如HF起始压力，接近压力和NF起始压力）产生重大影响。研究结果可为了解HF与NF之间的相互作用机理提供参考。