伸缩节在膨胀套管作业中的应用

Application of expansion joints to expandable casing operation

魏小房 王长宁 李前春 杨博 王莉

WEI Xiaofang WANG Changning LI Qianchun YANG Bo WANG Li

川庆钻探工程有限公司工程技术研究院，陕西西安　710018

Engineering Technology Research Institute of CNPC Chuanqing Drilling Engineering Company Limited, Xi’an 710018, China

降低膨胀套管施工中的膨胀压力是膨胀套管补贴取得成功的重要保证。对于液压膨胀方式而言，较小的膨胀压力可以降低施工风险。通过对膨胀套管在井下膨胀过程中压力变化的分析，指出由于送入油管柱的重力的影响，造成初始锚定过程中存在无法克服的附加压力，提出利用伸缩节消除附加膨胀压力、提高锚定效果的方法。2口井的现场施工证明，在难以把握的膨胀管锚定阶段，也是膨胀压力最高的环节使用伸缩节，膨胀作业的压力与室内试验相比增加很少。伸缩节不仅能够降低膨胀作业过程中的最大压力，还能提高锚定效果，方便司钻的操作，特别适用于深井膨胀作业。

To decrease the expansion pressure during expandable casing operation is important to ensure successful expandable casing path. For hydraulic expansion, smaller expandable pressure could reduce operation risk. Through the analysis of the pressure variation of expandable casing during downhole expansion, it is put forward that the gravity of tubing string may lead to the additional pressure that is insurmountable during initial anchoring, expansion jonints could be used to remove additional expansion pressure and improve anchoring. Through field operation, the use of expansion joints at the stage of expansion casing anchoring that is difficult to master, i. e. the stage of the highest expansion pressure, the pressure during expansion increases less as compared to lab test. Expansion joints could not only decrease the maximum pressure during expansion, also improve anchoring effect. They are easy to operate, especially applicable to deep well expansion.