可溶桥塞技术在页岩气井套管测漏中的应用

Application of Dissolvable Bridge Plug on Casing Leakage Detection in Shale Gas Well

在页岩气井油层套管化学剂堵漏挤注施工之前,为了获取漏失数据并实现暂堵转向,需对漏点以下井筒进行有效暂堵隔离。为此,研制了可溶桥塞及配套送入工具,并开展了室内性能测试和现场试验。性能测试及现场试验结果表明:桥塞在承压差70 MPa条件下密封时长大于24 h,桥塞在93℃、氯根质量浓度10 g/L的返排液环境中溶解时长小于15 d,桥塞丢手方式设计合理,承压密封性能稳定,溶解性能良好,满足化学堵漏漏速测试及暂堵转向的施工要求。所得结果可为页岩气井套管堵漏措施的制定及后续化学堵漏施工的顺利开展提供技术支撑。

To obtain the leakage data and realize temporary plugging diversion before the injection of chemical agent in the production casing of shale gas wells,effective temporary plugging of the wellbore below the leakage point is required.In view of this,the dissolvable bridging plug and supporting tools has been developed and related laboratory performance tests and field tests have been carried out.The results of performance test and field test showed that the sealing time of the bridge plug is longer than 24 h under the pressure difference of 70 MPa.The plug dissolution time is less than 15 days within the flowback fluid with the chloride concentration of 10 g/L at 93℃.The bridge plug has the feature of reasonably designed release,stable pressure bearing and sealing performance and good solubility,which meets the requirements of leakage speed test of chemical plugging and temporary plugging diversion operation.The study results provide technical support for the development of shale gas well casing plugging measures and the subsequent chemical plugging operation.