非常规油气储层渗透率低，通过水力压裂产生复杂连通的压裂缝网是非常规致密油气高效开采的前提，而影响复杂裂缝网络形成的关键因素是水力裂缝与天然裂缝的沟通机制。对ABAQUS有限元软件进行二次开发，通过采用0厚度cohesive单元方法，建立离散裂隙网络（discrete fracture network, DFN）模型，采用声发射模拟方法监测整个压裂过程中的声发射数据，综合数值模拟结果和声发射模拟结果研究了排量大小和地应力条件对水力裂缝扩展过程的影响。结果表明：水力压裂缝网形成演化受排量大小和地应力差的影响，地应力差越小，主裂缝的裂缝宽度越大，且越容易在主裂缝两侧产生次级裂缝；地应力差越大，越容易产生水力裂缝，但形成的裂缝路径单一，难以形成复杂的裂缝网络；排量越大，水力裂缝越早起裂，裂缝扩展速度越快，压裂效果越好。

The permeability of unconventional oil and gas reservoir is inefficiency. Hydraulic fracturing produces the complex network of connected fractures as a prerequisite for efficient exploitation of unconventional oil and gas. The key factor affecting the formation of complex fracture network is the communication mechanism between hydraulic fracture and natural fracture. Based on the secondary development of ABAQUS software, discrete fracture network(DFN) model was established by using 0 thickness cohesive element, and acoustic emission simulation was used to detect the acoustic emission data in the whole fracturing. Based on the numerical simulation results and acoustic emission simulation results, the effects of displacement and in-situ stress conditions on the propagation process of hydraulic fractures were studied. The results show that the evolution of hydraulic fracture network is affected by displacement and in-situ stress difference. The smaller the difference of in-situ stress, the larger the width of the main fracture, and the easier to produce secondary cracks on both sides of the main fracture. The larger the difference in in-situ stress, the easier to produce hydraulic fractures, but the single fracture path is difficult to form a complex fracture network. The displacement becomes larger, so the hydraulic fracture starts earlier, the fracture propagates faster and the fracturing effect becomes better.