Research on Fractures in Hydraulic Fracturing Reservoirs

Hydraulic fracturing is an important technology for unconventional natural gas extraction. It generates volume opening in the reservoir by injecting a fluid volume exceeding the reservoir's pore elasticity, thus opening up migration channels for free gas. The fracturing effect is significantly influenced by the distribution of natural fractures and fissures in the reservoir. Natural fractures are crack systems formed in rocks under natural conditions and are widely present in unconventional reservoirs such as shale, tight sandstone, and coal seams. During the hydraulic fracturing process, they communicate with hydraulic fractures to form complex fracture networks. Moreover, natural fissures can alter the stress field distribution in the reservoir, affecting the initiation and propagation behavior of fractures. Therefore, this paper focuses on the impact of fractured reservoirs on fracturing effects, providing theoretical references for optimizing fracturing designs.