中文摘要：

页岩储层物性极差,必须通过体积改造形成网状裂缝系统才能实现经济有效开发,掌握页岩地层中诱导裂缝延伸规律是成功实现缝网压裂的基础。借助基于细观损伤力学和弹性力学研发的岩石破裂分析系统RFPA2D,开展了页岩储层在水力压裂过程中的裂缝形成及延伸规律研究。在考虑到地层非均质的前提下,结合页岩本身的力学特性,分析了井周天然裂缝长度及密度对井周诱导缝形成及发展的影响。结果表明,井壁天然裂缝越长、密度越大,其开启可能越大,开启后伴生诱导缝发育程度越高。另外,对不同地应力差下天然裂缝长度影响开展的研究表明,低应力差下,即使天然裂缝较短,也会被打开,伴生诱导缝延伸具有较强的随机性,在天然裂缝长度较长的情况下,伴生诱导缝倾向于沿天然裂缝方向继续发展。

英文摘要：

Because of the low porosity and permeability, share gas reservoirs can achieve effective production only after network hydraulic fracturing, and the rule of fracture propagation which acted as the basis of realizing network fracturing should be understood. With the help of rock failure process analysis （RFPA2D） which based on meso-damage mechanics and elastic mechanics, the formation and propagation of fracture in the process of shale hydraulic fracturing were analyzed. Given the heterogeneity of formation and combined the real mechanical properties of shale, the influence of length and density of natural frac- tures around borehole on the formation of induced fracture was discussed. The result indicated that with longer natural fracture and higher density, it is more likely to open the natural fracture, and the develop- ment degree of the induced fracture after the natural fracture opened could be higher. Moreover, the effect of length of natural fracture under different insitu stresses was discussed as well, the research showed that the natural fracture would be initiated even if it was short under low differential stress condition, and the propagation of the induced fracture could be under high randomness, with long natural fracture, the in- duced fractures were inclined to extend along with the natural fracture.