水泥浆防气窜性能评价新方法  

A new method to evaluate gas migration prevention performance of cement slurries

作　　者：朱海金[1] 屈建省[1] 刘爱萍[1] 邹建龙[1] 许加星[1] 

机构地区：[1]天津中油渤星工程科技有限公司

出　　处：《天然气工业》2010年第8期55-58,共4页Natural Gas Industry

基　　金：中国石油天然气集团公司基础研究项目"天然气井固井水泥环封隔性能研究"(编号:2008A-2304);中国石油天然气集团公司科研项目"乌兹别克斯坦费尔甘纳盆地深井超深井钻井技术攻关及现场试验"(编号:2008E-1607)

摘　　要：目前固井行业缺乏可结合实际情况进行水泥浆防气窜性能的评价方法,导致在单井设计中水泥浆的防气窜性能难以把握。通过规范水泥浆静胶凝强度的试验分析,提出将环空水泥浆柱视为由多段长度为30.48m的水泥浆柱组成,考察最接近气层水泥浆柱能否抵抗气侵从而延绅至井口的整个水泥浆柱的环空水泥浆防气窜性能的评价新方法。使用该方法对固井水泥浆配方进行了研究,并结合气田的现场尾管固井实例对所选水泥浆配方进行了评价。结果表明,在水泥浆的防气窜设计中仅强调控制水泥浆失水或缩短水泥浆候凝期间的过渡时间是不够的,必须提高水泥浆在候凝期间的内部结构阻力或降低水泥浆在候凝期间的渗透率,才能确保气井的固井质量。该方法可指导入井水泥浆的防气窜性能设计及评价。There are no methods nowadays to evaluate the gas migration prevention performance of cement slurries based on actual conditions,which results in uncertain circumstances during a single well's planning.Here this paper presents a new evaluation method,which proposes to deem the whole cement slurry column in the annulus as being consisted of many smaller sections of 30.48 m slurry columns,then by standard experimental analysis of the static gel strength of the cement slurry to study whether the slurry columns can resist the gas migrating up from the gas zones,starting at the slurry column closest to the pay zone and extending to the whole column till wellhead.This method was used to study the formulation of cement slurry and the actual cement slurry used for liner cementing at gas fields was taken into consideration to evaluate the formulation.The test results show that it is insufficient only considering water loss control and the shortening of WOC,but only if it is a must to increase the internal structural friction or reduce the permeability of the cement slurry during the WOC period,the cementing quality in gas wells can thus be guaranteed.This method can be used for the design and evaluation of the gas migration prevention performance of the cement slurry pumped dowhole.

关 键 词：深井 超深井 固井 水泥浆 防气窜 评价方法 静胶凝强度 

分 类 号：TE256[石油与天然气工程—油气井工程]