复杂深井尾管固井及回接技术实践

尾管悬挂固井是一种工程经济效益较高、注水泥环空阻力较低且有利于改善套管柱轴向设计和再钻进水力条件的固井方法，常常应用于深井超深井的固井作业。鄯科1井是一口科学探索井，完井尾管具有井径极不规则（实测井径扩大率最大为139.82%，最小为－6.02%）、施工压力高（15~20 MPa）、封固段长（考虑水泥余量的情况下封固段可长达1500 m）和尾管回接固井要求封固两头且不使用分级注水泥等难点。文章针对固井难点，总结出一套适用于复杂深井尾管及其回接固井的优化设计关键技术，它主要包括管串选择、套管扶正器加法、水泥浆体系优选、施工压力校核和配套工艺措施。实践证明，这些技术对类似井的固井作业具有实际的参考价值。

CEMENTING AND TIE-BACK TECHNIQUES WITH TAIL PIPE FOR COMPLICATED DEEP WELLS

The well cementing with tail pipe hanging is a cementing method, which has high economic benefit of engineering, low annulus resistance while cementing, and is favorable to improve the axial design of casing string and the hydraulic conditions of re-drilling. So, the method is often used for the cementing jobs of deep or super-deep wells. Well Shanke 1 is a scientific exploration well. There are many problems for the well completion with tail pipe, such as the borehole diameter very irregular (the maximum diameter enlargement: 139.82% and the minimum: -6.02%); the operating pressure high (15-20 Mpa); the cementing section long (the section up to 1500 m considering the cementing surplus); and the tail-pipe tie-back cementing requires to cement the both ends without using stage cementing device, etc. Aiming at these problems, it is summed up a series of key techniques for optimized design that are suitable to the cementing with tail-pipe and tie-back in complicated wells. They mainly include: the string selection; the installing method of casing stabilizer; the optimization of slurry system; the verification of operating pressure and the matching process measures. Practice proves the techniques are feasible and reliable, which will surely provide practical reference for the cementing jobs of similar wells.