文23储气库钻井工程关键技术

Key technologies in drilling engineering of Wen 23 underground gas storage

廖权文 胡建均 史怀忠 宋恒宇

LIAO Quanwen HU Jianjun SHI Huaizhong SONG Hengyu

中石化中原石油工程有限公司 中国石油大学(北京)油气资源与探测国家重点实验室 中国石油集团工程技术研究院有限公司

SINOPEC Zhongyuan Oil Engineering Co., Ltd., Fuyang 457001, He’nan, China State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China CNPC Engineering Technology R&D Company Limited, Beijing 102206, China

文23储气库地层压力低、层系复杂、流体矿化度高，长期交变注采易造成生产套管及水泥环失效，给钻完井工程带来了一系列挑战。从文23储气库井身结构、钻井液体系、储层保护、井筒密封完整性等方面着手，优化形成了适用于文23储气库井的三开次和四开次井身结构设计方案，研发出了适用于文23储气库低压、易漏储层的微泡防漏钻井液体系，优化设计了以可自降解超细钙、可变形封堵剂、微纤维为主要屏蔽暂堵剂的储层保护基础配方，研制了适用于非盐层段技术套管、盐层段技术套管以及生产套管段的水泥浆体系，结合配套的固井工艺，形成了盐盖层和低压易漏地层固井技术。现场应用结果表明，该技术有效保护了文23储气库枯竭储层，提高了井筒密封完整性，进而保障了储气库的安全平稳运行。

The Wen-23 gas storage features low formation pressure, complex formation systems and high formation fluid salinity. The long-term alternating injection-production tends to trigger the failure of production casing and cement sheaths, which brings a series of challenges to drilling and well completion engineering. From the perspectives of the casing program, drilling fluid system, reservoir damage prevention and wellbore integrity of wells in the Wen-23 gas storage, the design schemes of the third and fourth casing sections were optimized, and the micro-foam lost circulation-preventive drilling fluid system suitable for low-pressure and highly-permeable reservoirs of the Wen-23 gas storage was developed. The reservoir damage prevention basic formula was presented, which mainly consists of self-degradable ultrafine calcium, deformable plugging agents and micro-fibers as main temporary plugging agents, and the cement slurry systems suitable for non-salt intermediate casing section, salt-rock intermediate casing section and production casing section were developed. Such slurry systems together with the matching cementing practices form the cementing technology of salt caprock and low-pressure thief zones. Field applications showed that this technology effectively protects the depleted reservoir of the Wen-23 gas storage, improves the well integrity, and thus, ensures the safe and stable operations of the gas storage.

10.13639/j.odpt.2023.02.005