东海复杂泥岩地层钻井关键技术研究与实践

Research and Practice of Key Drilling Technologies in Complex Mudstone Formations in East China Sea

徐佳

XU Jia

中海石油（中国）有限公司上海分公司，上海　200335

Shanghai Branch, CNOOC (China) Ltd., Shanghai 200335, China

为解决东海部分区块龙井组、花港组上部灰绿色复杂泥岩段作业中出现的倒划眼困难、憋压蹩扭矩、测井遇阻、卡钻等井下复杂问题，通过分析复杂泥岩地层岩石组构特性、理化特性以及力学特性，研究井壁失稳机理，分析不同钻井液性能和钻井工况下起下钻阻卡的影响规律和程度，为现场制定复杂情况的处理措施提供理论依据，形成了优化的现场油基钻井液性能及施工工艺。相关技术在现场复杂泥岩地层实践应用后，逐步实现了龙井组、花港组复杂泥岩地层钻井时的井壁稳定，起下钻时效提高了96.3%～353.1%，大幅提高了作业时效，降低了钻井成本，成功解决了东海复杂泥岩地层的安全高效钻井问题，为类似地层钻井提供了借鉴。

In order to solve the complex downhole problems such as difficulty in back reaming, compression torque, logging resistance, and sticking in the operation of grey green complex mudstone sections in the upper part of Longjing Formation and Huagang Formation in some blocks of East China Sea, the mechanism of wellbore instability was studied by analyzing the rock fabric characteristics, physical and chemical properties and mechanical properties of complex mudstone formations. This paper analyzes the influence law and degree of tripping resistance under different drilling fluid properties and drilling conditions, and provides a theoretical basis and foundation for treatment measures for complex situations on site, and forms an optimized field oil-based drilling fluid performance and construction technology. After the practical application of the related technology in the field of complex mudstone formation, the borehole stability during drilling in the complex mudstone formation of Longjing Formation and Huagang Formation was gradually realized, and the tripping time was increased by 96.3%～353.1%, which significantly improved the operation time and reduced the drilling cost. The problem of safe and efficient drilling in the complex mudstone formation in East China Sea was successfully solved, which provided a reference for drilling in similar strata.

https://doi.org/10.3969/j.issn.1008-2336.2023.01.063