套损井密封加固技术新进展

NEW ADVANCE OF SEALING CONSOLIDATION TECHNIQUE FOR CASING-DAMAGED WELLS

套损井密封加固技术是由修井作业初期简单的不密封式吊管加固和丢手加固发展而来，但对高难套损井修复成功率较低。进而发展的锚瓦式液压密封加固和燃爆焊接加固技术是两项较为成熟的密封加固技术，但也存在加固后内通径缩小幅度较大，无法分层开采，悬挂力小，密封不可靠等问题。结合油田在修井方面的最新研究成果，提出了膨胀管加固技术和错断井复合材料修补技术。膨胀管加固技术利用金属材料的塑变性，通过外力使管体膨胀，整体贴于套管内壁，实现锚定与密封，解决了密封不可靠、锚定力小、加固后内通径缩小的问题，并可实现长井段加固；错断井复合材料修补技术将凝固后具有高强度，高韧性，耐高温的复合材料挤注到套管错断部位，形成与钢管性能相近的复合材料固化环，连接上下套管实现密封，有效地修补破损的水泥环，内通径大于118mm，能完全满足常规采油工具起下和分采分注的要求。实践证明，这两项技术有效地提高了油田高难套损井修复成功率和利用率。

The sealing consolidation technique for the casing-damaged wells comes from development of consolidation of the unsealing hanging pipe and the release at the early stage of workover, but the success rate is low for highly difficult restoration of the casing-damaged wells. The anchor-tile type hydroseal and the ignite-explode welding are the more mature consolidation techniques, but there are still some problems that the reduction of the drift diing are the more mature consolidation techniques, but there are still some problems that the reduction of the drift di- ameter is larger after consolidation, the separate zone production can not be conducted, the hanging force is small,and the sealing is not reliable. Combining the current research results from workwover in oilfields, this paper proposes the swell tube consolidation and the composite material patching for the dislocated wells. Using the plastic deformation, the swell tube consolidation technique causes the tube body to swell through the outside force, the tube body is entirely pasted on the inside wall of casing, anchoring and sealing are realized, the problems that the sealing is not reliable, the anchoring force is small, the inner diameter is reduced after consolidation, and consolidation for the long intervals can be realized; using the composite material patching technique for the dislocated wells, the composite material with high strength, high tenacity and resistance to high temperature is squeezed to the dislocated position of casing to form the composite material consolidation ring similar with properties of steel pipes, realize the sealing by joining the upper and lower casings, effectively patch the damaged casings. The inner drift diameter is 118 mm, being able to completely satisfy requirements for running and pulling conventional production tools and separate zone production and injection. Practice proves that both techniques effectively have raised the restoration success rate and utilization ratio of casing-damaged wells with high difficulties in oilfields.