页岩气水平井可溶性桥塞室内测试及现场试验

Lab and field tests of dissolvable bridge plug technology in shale-gas horizontal wells

可溶性桥塞技术既能有效解决复合桥塞钻磨施工投入大、风险高、连油自锁、套管变形等造成桥塞无法钻除而影响后续生产的难题,又能成功弥补大通径桥塞不能实现井筒全通径,无法开展后期生产测井及重复压裂等作业的不足,可最大程度保证井筒完整性。通过开展可溶性桥塞室内测试,评价了桥塞可溶材料与现场应用工况的适应性,确保了桥塞能够满足现场压裂及后期溶解要求。在CNH13-1井开展了可溶性桥塞现场先导试验,压裂前桥塞泵送、座封丢手正常,压裂时桥塞承压密封性能稳定,压裂后桥塞溶解性能良好,试验结果基本达到了预期效果。

Dissolvable bridge plug is superior to composite one because the latter is featured by higher investment in both drilling and grinding, higher risk, coiled-tubing possible self-locking, and casing deformation frustrating bridge plug to impede subsequent operations. Moreover, dissolvable one can maintain wellbore integrity to the utmost, so it is also better than large bore bridge plug which fails to ensure a full bore and thus disables the next production logging and refracturing. In this study, lab test was conducted on dissolvable bridge plug to evaluate the adaptability of materials to field, so as to guarantee that this one can satisfy the requirements of site fracturing and later dissolution. Its field pilot test was carried out in CNH13-1 well. And the dissolvable bridge plug was found with normal pumping and setting before fracturing, stable pressurized sealing performance during fracturing, and successful dissolution after fracturing. Obviously, these obtained results basically meet expectations.