顺北油气田辉绿岩地层井壁稳定钻井液技术

Drilling Fluid Technology for Wellbore Stability of the Diabase Formation in Shunbei Oil & Gas Field

李凡 李大奇 金军斌 张杜杰 方俊伟 王伟吉

LI Fan LI Daqi JIN Junbin ZHANG Dujie FANG Junwei WANG Weiji

页岩油气富集机理与有效开发国家重点实验室, 北京 102206 中石化石油工程技术研究院有限公司, 北京 102206 中国石化西北油田分公司石油工程技术研究院, 新疆乌鲁木齐 830001

State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing, 102206, China Sinopec Research Institute of Petroleum Engineering Co., Ltd., Beijing, 102206, China Petroleum Engineering Technology Research Institute, Sinopec Northwest Oilfield Company, Urumqi, Xinjiang, 830001, China

针对顺北油气田辉绿岩地层钻井过程中井壁坍塌失稳的技术难题，采用X射线衍射、扫描电镜、高压压汞、线性膨胀、滚动回收率、三轴岩石力学测试仪等方法，研究了辉绿岩组构特征、理化性能，分析了岩石力学性能及钻具振动对辉绿岩井壁稳定的影响。分析结果表明，微裂缝的弱面效应易诱发辉绿岩岩体井壁垮塌失稳，钻具的扭转振动、横向振动会对辉绿岩井壁失稳产生较大影响。为此，对钻井液密度、封堵性能和携岩性能进行优化，形成了辉绿岩井壁稳定钻井液技术，并制定了配套的技术措施。辉绿岩井壁稳定钻井液技术在顺北X井三开应用后，顺利钻穿厚22 m的辉绿岩，钻进过程中钻井液性能良好，没有出现明显的复杂情况，起下钻正常，井段平均井径扩大率仅为6.0%。辉绿岩地层井壁稳定钻井液技术能够保证辉绿岩井段的安全顺利钻进，井眼规则，对解决辉绿岩井壁失稳复杂具有较好的效果。

In view of the complex wellbore collapse and instability during the drilling of the diabase formation in Shunbei Oil& Gas Field, X-ray diffraction, scanning electron microscopy (SEM), high-pressure mercury injection, linear expansion, rolling recovery, triaxial rock mechanics tester, and other methods were used to investigate the fabric characteristics and physical and chemical properties of the diabase formation. Meanwhile, the influence of rock mechanical properties and the drilling tool vibration on the wellbore of the diabase formation were analyzed.The results indicated that the weak surface effect of micro-fractures could easily induce wellbore collapse and instability of the diabase rock mass. In addition, the torsional and lateral vibration of the drilling tool had a greater impact on the wellbore instability of the diabase formation. Then, the density , plugging performance, and rock-carrying performance of the drilling fluid were optimized, and the drilling fluid technology for wellbore stability of the diabase formation was proposed with its supporting drilling technologies developed. The technology was applied in the three-section casing of Well Shunbei X, and the diabase formation with a thickness of 22 m was drilled successfully. During the drilling process, the performance of the drilling fluid was satisfactory, and there were no obvious complications, and tripping operated normally. Furthermore, the average borehole diameter expansion rate of the well section was only 6.0%. The drilling fluid technology for wellbore stability of the diabase formation could ensure the safe and smooth drilling of diabase sections and regular boreholes. Thus, it has an excellent effect on solving the complex wellbore instability of the diabase formation.

国家自然科学基金项目“高温高压油气安全高效钻完井工程基础理论与方法”（编号：U19B6003-05）及国家重点研发计划项目“井筒稳定性闭环响应机制与智能调控方法”（编号：2019YFA0708303）联合资助

https://doi.org/10.11911/syztjs.2022041