调整井防窜水泥浆体系的优选与实践

Optimization and Usage of Antichannelling Cement Slurries for Cementing Adjustment Wells

油气水窜是调整井固井中遇到的突出问题。针对吐哈油田调整井固井的特点 ,从多种商品油井水泥外加剂中筛选出了 4种外加剂 :分散剂USZ ;降滤失剂RC80 0 ,缓凝剂Tw2 0 0R和防气窜剂KQ B ,通过配方优选实验 ,用强华G级油井水泥 (HSR)和 4种外加剂配制成了适用于不同井温条件的 4种调整井固井水泥浆配方 ,给出了配方组成和在相应条件下的性能。探讨了该水泥浆体系的防窜机理 :RC2 0 0的阻力作用 ;KQ B的保压作用 ,USZ的触变作用。指出该防窜水泥浆体系用于吐哈油田各区块 2 0 0多口调整井固井时 ,固井合格率为 10 0 % ,优质率为95 %。

Fluid channelling is a trouble problem in cemented adjustment oil wells. For cementing such wells in Turpan Hami oil fields, four additives are selected experimentally from a lot of commercial oilwell cement additives(dispersant USZ, water loss controller RC800, set retarder Tw200R, and antigaschannelling agent KQ B) and on the base of Qianghuas oilwell cement D(HSR) and by introducing these additives, four cement slurries of optimal composition are prepared for well cementing adjustment wells of different downhole temperatures and their composition and performance properties are presented. The antichannelling mechanisms involved in well cementing by these slurries are considered as: resistance exerted by RC800, pressure maintanance by KQ B, and thixotropy contributed by USZ. It is stated that cementing operations in more than 200 adjustment wells at Turpan Hami with these slurries are performed with 100% acceptable quality and 95% excellent quality.