页岩气井套变段体积压裂技术应用及优选

Application and Optimization of SRV Fracturing Technology for Casing Deformation Section of Shale Gas Well

套管变形会导致套变段以下无法应用泵送桥塞进行分段压裂,严重影响页岩气水平井的分段体积压裂改造效果。鉴于此,分析了3种页岩气水平井分段压裂改造工艺(暂堵转向、机械封隔和水力喷射)的适用性和优缺点,概述了3种套变段压裂技术(可降解暂堵球、缝内填砂和复合暂堵多级转向)在四川盆地长宁-威远区块的应用情况,进而优选出套变段分段体积压裂技术。研究结果表明:对轻度和中等变形的套变影响段采用缝内填砂或暂堵球技术分段,分段可靠性相对较好;对复杂和长度较长的套变影响段采用复合暂堵分级转向压裂工艺,施工风险较低。

The casing deformation can lead to failed multistage fracturing using pumped bridge plug in the lower well section, which could affect seriously the effect of the multistage SRY fracturing of the shale gas horizontal well. In view of this, the applicability and advantages and disadvantages of three kinds of shale gas horizontal well fractu-ring technologies （temporary plugging and diverting, mechanical sealing and hydraulic jet） have been analyzed. The applications of three kinds of fracturing technologies for casing deformation well section （ degradable temporary plug ball, fracture filled with sand and composite temporary plugging multistage diverting technology） in the Changning- Weiyuan block in the Sichuan Basin have been summarized, and then the multistage SRV fracturing technology for casing deformation well section has been selected. The results show that the fracture filled with sand and temporary plug ball technology are relatively reliable for the mild and moderate casing deformation section. The composite temporary plugging multistage diverting fracturing technology has low risk for the complex and long casing deformation well section.