Perforating cluster space optimization method of horizontal well multi-stage fracturing in extremely thick unconventional gas reservoir

摘要

X5 reservoir is a 3000 m deep tight sand-shale interbedded thick reservoir. The horizontal principle stress ratio is around 0.45. The minimum horizontal principle stress is 75-80 MPa, and natural fractures are not abundant. Those conditions limit the generation of fracture network. Treatments based on previous fracturing design have not received good production. Due to extremely thick formation and lack of significant stress barrier, it is hard to maintain the fracture height in expected section.