海上薄油层多分支水平井钻井技术

Drilling technology for multi-lateral horizontal wells for thin reservoir in offshore oilfield

为提高海上中后期油田的生产能力,针对储量分散、天然能量弱的薄层油藏,决定采用多分支水平井技术提高单井产量和采收率,降低综合开发成本。根据某海域A油田的油藏特点,分析了薄油层钻井作业设备能力有限、工程设计限制多、中靶精度要求高、井眼轨迹控制挑战多、钻井施工风险高、储层保护难度大等问题。通过对平台钻井设备评价改造、井身结构及井眼轨道优化设计、复杂井眼轨迹的精细控制、钻井液优选等方面的研究及应用,成功实施了水平井、分支井、小井眼和薄油层的钻探作业,提高了油田勘探开发整体效益,为今后海上薄油层多分支水平井的钻井作业提供了参考。

In order to improve the productivity of mid-late stage offshore oilfields, multilateral horizontal wells are used for thin reservoirs with scattered reserves and insufifcient natural energy to improve the production of invidual wells and recovery rate and to reduce the comprehensive development costs. Based on the characteristics of oil reservoirs in A Oilfield in some sea area, we analyzed some issues like limited drilling equipment capability, the many restrictions in engineering design, high requirement on target hitting, multiple challenges of trajectory control, high-risk drilling operations, great dififculties in eservoir protection, etc. The research and application of evaluation and modiifcation of the drilling equipment, optimized design of casing program and well trajectory, ifne control of well trajectory and optimization of drilling lfuid technology, etc. ensured the successful drilling of horizontal wells,multilateral wells, slim holes and thin reservoirs, which has improved the comprehensive beneifts of oil ifeld exploration and development and provides a reference for drilling multilateral horizontal wells for thin reservoirs in offshore oilifelds.