川西深井固井工艺现状及存在问题分析

ANALYSIS ON THE STATUS AND EXISTING PROBLEMS OF CEMENTING TECHNOLOGIES FOR DEEP WELLS IN WESTERN SICHUAN BASIN

川西深井井下条件复杂,深部地层CO2含量较高,储层压力高、气显示活跃且气层多,固井防气窜难度大,固井难点较多。而包括尾管悬挂、双级固井技术、长封固段双胶塞固井技术及低密度水泥浆固井的几种特殊固井工艺技术对工具工艺要求较高。文中分析了这几种固井工艺的优缺点及应用情况,并在此基础上,分析和总结了深井固井中存在的问题,提出了一些解决深井固井的方法,对今后提高川西地区深井固井质量具有现实意义。

For deep wells in western Sichuan Basin, it′s very hard to carry out a cementing, especially a big difficulty existing in anti-gas channeling, due to complicated borehole conditions, rich CO2 content in deep formation, high reservoir pressure, very active gas show and many gas layers. However, several special cementing technologies, including liner hanging cementing, two-stage cementing, long cementing segment and double-plug cementing as well as low-density slurry cementing, ask for much higher requirements for cementing equipments. This paper analyzes the technologies′ advantage and disadvantage and their application, and then summarizes the existing problems of deep-well cementing, at last presents some solution which can play a vital role in improving the cementing quality for deep wells in western Sichuan Basin.