提高高压气井套管回接固井质量的技术

为了解决套管回接固井常出现的质量不佳和井口带压的问题，在实验的基础上，提出套管回接固井作业时应先泵入低黏、抗钙钻井液和大量冲洗液彻底冲刷套管壁，水泥浆中应加入膨胀剂和纤维，改善水泥石力学性能，确保水泥环与套管胶结质量。采用高能混浆设备配浆和井口憋压候凝，确保水泥浆密度均匀，防止水泥浆体积收缩、管柱膨胀和水泥环微环隙的形成。几口试验井的声波测井结果表明：所采取的技术措施行之有效，能够保证套管回接固井质量。

Technology of improving the quality of casing tie-back cementing in high-pressure gas wells

In order to solve the problems of poor cementing quality and sustained casing pressure of casing tie back cementing, it is recommended to pump downhole low viscosity calcium service drilling fluid and large amounts of washing fluid to flush the casing wall thoroughly before hand. And expansion agent and fibers should be added in the cement slurry to improve the mechanics of the cement stones so as to ensure the bond quality between the cement sheath and casing. Large power mixing machine should be used for slurry preparation and wellhead backpressure be applied during WOC period to ensure the uniformity of slurry density and prevent volumetric shrinkage of slurry, expansion of casing string and micro annulus formed in cement sheath. The acoustic logging results of test wells indicate that the technical measures adopted are effective, enough to ensure the quality of casing tie back cementing.