膨胀管技术在钻井过程中的研究与应用

Research and Application of Expandable Pipe Technology in Drilling

膨胀管技术在钻井过程中主要用于解决漏失、套管下放不到位和高低压同层等问题。该技术不减小上层套管内径尺寸,原钻头及钻柱组合无需改变,特别是在深井和超深井的钻井中,膨胀管技术可封堵问题层段,并提供足够的作业通道。在介绍膨胀管技术发展现状的基础上,针对203.2 mm×244.5 mm规格的膨胀管串进行了组装和试验测试,结果表明优质膨胀管的膨胀率为21.3%,内通径达到222 mm。同时对管材膨胀后的抗内压和抗外压进行了测试,分别达到35和25 MPa,均未出现螺纹密封泄漏和塑性形变。最后在介绍膨胀管技术施工工艺的基础上指出,膨胀管技术可在不改变原有井身结构的条件下处理钻井遇到的问题,达到节约钻井成本、延长钻井深度的目的。

The expandable pipe technology is mainly used to solve problems such as leakage, improper easing landing and coexistence of high and low pressures in the same layer in the process of drilling. The technology does not reduce the upper casing＇s inner diameter. The original drilling bit and drilling assembly need not be changed. Especially in the process of deep well and superdeep well drilling, the technology can block the problematic interval and provide the sufficient operating channel. The Ф203.2 mm×Ф244. 5 mm expandable pipe string was assembled and tested through the experiment on the basis of introducing the current development situation of expandable pipe. The findings show that the expansion rate of quality expandable pipe is 21.3% and the internal diameter reaches 222 mm. Meanwhile, the testing of pipe＇ s resistance to internal and external pressures was conducted, reaching 35 MPa and 25 MPa respectively. Thread seal leakage and plastic deformation did not take place. Finally it is pointed out that expandable pipe technology can deal with the problems in drilling without changing the original borehole structure, as a result the purposes of saving the drilling cost and increasing the drilling depth have been achieved.