页岩储集层水平井段内多簇压裂技术应用现状及认识

Application and Cognition of Multi-Cluster Fracturing Technology in Horizontal Wells in Shale Reservoirs

水平井段内多簇压裂技术能增加页岩储集层压裂裂缝复杂程度,提高簇间动用率,是有效改造页岩储集层的核心技术。对北美页岩气区块和中国四川盆地南部页岩气区块水平井段内多簇压裂技术的应用现状进行分析,并结合技术原理提出了几点认识:段内多簇压裂应与井间距合理匹配,并配套采用暂堵转向技术和限流射孔技术,增大射孔簇簇效率,促进裂缝均匀扩展,提高段内多簇压裂改造效果;北美页岩气区块采用段内多簇压裂技术增产,实现了页岩储集层高效开采,川南页岩气区块水平井段内多簇压裂技术起步较晚,目前在300~400 m井间距下主要开展了段内为6~8簇压裂现场试验;为了降低压裂成本、提高作业时效,长段多簇压裂将是实现效益开发的一个重要发展方向;但随着段内簇数不断增加,射孔技术、暂堵转向技术、射孔簇数与施工参数合理匹配等方面面临新挑战,亟需进一步研究,从而形成适合不同地区地质工程特征的段内多簇压裂技术。

Multi-cluster fracturing technology in horizontal well is one of key technologies to stimulate shale reservoirs efficiently,which can increase hydraulic fracture complexity and enhance pay-gross ratio among clusters.In this paper,the application status of multi-cluster fracturing technology in the shale reservoirs in North America and southern Sichuan basin is stated and some opinions are presented by combing with its mechanism.Multi-cluster fracturing technology should match with well spacing,diversion technology and limited-entry perforation technology should be used to improve cluster efficiency and promote fracture propagation evenly so as to increase multi-cluster fracturing effectiveness.Multi-cluster fracturing has been extensively applied in the shale areas in North America to enhance production and realize efficient development,but the technology in the shale area in the southern Sichuan basin started relatively late and at present field tests of the hydraulic fracturing technology with 6-8 clusters in horizontal sections have been conducted in horizontal wells with the well spacing of 300-400 m.In order to reduce cost and improve operation efficiency,long horizontal section multi-cluster fracturing is considered as a promising trend for efficient development.However,with the increase of cluster number,the matching of perforation technology,diversion technology,cluster number with operation parameters is facing challenges,and a multi-cluster fracturing technology suitable for different geological and engineering characteristics of the target areas needs to be further studied.