超深井注水泥塞技术

近几年,超深井逐年增多,由于井下落物、井斜超标、封隔高压层等原因,超深井注水泥塞也在增加。文章分析了超深井注水泥塞存在井下高温对水泥浆性能要求高;井下高压气层使水泥塞质量不好保证;井眼小、注灰量少,易混浆;井深替浆量大,准确计量困难等技术难点。针对以上问题进行研究,并根据川东北和塔里木注超深井水泥塞的现场实践经验,从做好水泥塞设计、水泥浆化验与损害试验、现场施工控制等方面介绍了注超深井水泥塞的技术对策,以川东北超深井YB3井(井深7450m)和塔里木超深井YQ6井(井深7510m)为例介绍了注超深水泥塞施工的技术措施与实施效果,并提出了注超深井水泥塞的建议,为今后超深井注水泥塞施工提供重要的借鉴作用。

CEMENTING PLUG TECHNIQUE IN ULTRA-DEEP WELL OF WESTERN REGION

In recent years,more and more ultra-deep wells were drilled in western region,the operation of cementing plug also increased because of bottom hole junk,excess hole inclination,or separating high pressure strata etc.When cementing plug in ultra-deep well,since high temperature in the hole,the requirement for the performance of cement slurry is very demanding.The existence of high pressure gas bearing formation makes it difficult to guarantee the quality of cement plug.The amount of cement injecting is limited for the small size of hole,so mixing slurry is easy.Since the well is extremely deep and long section,accurate gauging procedure of the voluminous displacement fluid is difficult.On the basis of in-situ experience,cementing plug technologies in ultra-deep well were introduced from plug design,cement testing and pollution experiment aspects,and the cementing plug effects were also introduced in Well Yuanba 3 and Yuqi 6.At last,the some suggestions of cementing plug were proposed in ultra-deep well.