南苏丹3/7区油田钻遇复杂及对策分析

Analysis on Drilling Troubles and Countermeasures of the 3/7 Block Oilfield in South Sudan

摘要: 不同的油田区块、不同的地层和岩性，钻井作业过程中常会出现各种不同的钻井复杂情况。南苏丹3/7区油田地层岩性以泥岩和砂岩为主，钻井作业过程中容易出现地层漏失和井眼缩经垮塌。本文分析了该区地层岩性，总结了钻井过程中发生的地层漏失、缩径与坍塌、钻头泥包和卡钻等四类复杂问题。针对不同类型的钻井复杂，提出了合理有效的处理方法和预防对策，包括随钻堵漏技术、注水泥塞堵漏技术、难易渐进式方法解卡等。本文提出的钻井复杂技术对策将有利于减少南苏丹3/7区钻井的非生产时间，降低钻井成本，也为其他相似区块高效钻井提供了重要的借鉴。

Abstract: Different oilfields, different stratum and lithologies, there are different drilling troubles occurring during drilling operations. The lithology of the 3/7 oilfield in South Sudan is dominated by claystone and sandstone. During the drilling operation, the formation loss, tight hole and caving of the wellbore are prone to occur. This paper analyzes the formation lithology in this area, and summarizes four kinds of drilling problems such as formation loss, tight hole and collapse, balling up and stuck. Reasonable and effective treatment methods and preventive measures are proposed according to different drilling troubles, including leakage plugging technology while drilling, cement plugging technology, a progressive method from easy to difficult to solve the stuck, and so on. The drilling troubles technical countermeasures proposed in this paper provide an important technical reference for high efficient drilling in other similar blocks, and will help to reduce the non-production time, and lower the drilling cost in the 3/7 area of South Sudan.