页岩气井固井分级式环空憋压技术研究与应用  

Research and application of staged annular back-pressure technology for shale gas well cementing

作　　者：焦利宾 汪瑶[3] 代锋 郑友志 胡锡辉 唐雪媛 胡小强 孙坤 JIAO Libin;WANG Yao;DAI Feng;ZHENG Youzhi;HU Xihui;TANG Xueyuan;HU Xiaoqiang;SUN Kun(Engineering Technology Research Institute of Southwest Oil&Gas Field Company,PetroChina,Chengdu 610017,China;Engineering Technology Research Institute,National Energy R&D Center of High H2S Content Gas Reservoir Development,Chengdu 610017,China;Southwest Oil&Gas Field Company,PetroChina,Chengdu 610056,China;Sichuan Changning Natural Gas Development Co.,Ltd.,Chengdu 610056,China;Development Division of Southwest Oil and Gas Field Company,PetroChina,Chengdu 610056,China;Chuanqing Drilling Downhole Service Company,PetroChina,Chengdu 610052,China)

机构地区：[1]中国石油西南油气田分公司工程技术研究院,四川成都610017 [2]国家能源高含硫气藏开采研发中心工程技术研究所,四川成都610017 [3]中国石油西南油气田分公司,四川成都610056 [4]四川长宁天然气开发有限责任公司,四川成都610056 [5]中国石油西南油气田分公司开发事业部,四川成都610056 [6]中国石油川庆钻探井下作业公司,四川成都610052

出　　处：《复杂油气藏》2024年第3期253-258,共6页Complex Hydrocarbon Reservoirs

基　　金：中国石油西南油气田分公司科研项目“基于大数据分析的固井质量预评估技术研究”(20230309-05);四川长宁天然气开发有限责任公司科研项目“低压力系数区块低密度固井技术研究”(20230608-09)。

摘　　要：防止环空异常带压以提高固井水泥环密封完整性是页岩气井安全高效开发的有力保障。固井候凝期间,水泥浆因失重导致环空液柱压力下降,地层流体窜入环空发生窜流,通常严重影响固井质量。针对页岩气井固井难点,研究了现场用水泥浆的失重过程与静胶凝强度发展过程。结果表明:三种水泥浆中快干浆的静胶凝强度发展最快,过渡时间最短(30 min);在静胶凝强度达到48 Pa时,缓凝浆失重率为1.04%,快干浆失重率达到85.2%,在过渡时间段内(48~240 Pa之间),中凝浆的失重速率最快,缓凝浆和快干浆的失重速率较慢;基于模拟计算环空憋压过程,在Z201井进行了现场试验,结果显示固井质量得以改善,第一界面合格率为97%,第二界面合格率为95.9%,气层段水泥胶结良好。分级式环空憋压技术具有良好的应用前景。Preventing abnormal pressure in the annulus to enhance the seal integrity of cemented rings are crucial for the safe and efficient development of shale gas wells.During the cement setting period,the slurry density loss leads to a decrease in annular fluid column pressure,allowing formation fluids to invade the annulus and causing channeling,which typically compromises cementing quality.To address the cementing challenges in shale gas wells,we studied the weight loss process and static gel strength development of the cement slurries used in the field.The results indicate that among the three cement slurries,the fast-setting slurry exhibited the fastest development of static gel strength with the shortest transition time(30 minutes).At a static gel strength of 48 Pa,the density loss rate of the slow-setting slurry was 1.04%,while the fast-setting slurry reached a density loss rate of 85.2%.During the transition period(between 48 and 240 Pa),the medium-setting slurry exhibited the highest density loss rate,while the slow-setting and fast-setting slurries showed slower rates.Based on simulated calculations of the annular backpressure process,a field test was conducted in well Z201.The results showed improved cementing quality,with a primary interface pass rate of 97%and a secondary interface pass rate of 95.9%.The cement bond in the gas-bearing section was also good.The staged annular backpressure technology shows promising application prospects.

关 键 词：水泥浆 气窜 环空憋压 失重 静胶凝强度 固井质量 

分 类 号：TE242[石油与天然气工程—油气井工程]