苏77-5-8H井大斜度穿煤层安全钻井技术

摘要:

苏77-5-8H井为苏里格气田苏77区块第一口利用水平井提高山23组开发效益的大斜度穿煤层水平井，目的层山23储集砂岩上部发育厚度25～30 m的碳质泥岩和煤层段，由于煤系地层的特殊性，钻进过程中易坍塌，且煤系地层正好处于入靶前的造斜井段，钻井施工难度大、风险高。在分析了煤层井壁稳定机理基础上，针对苏77区块地层特性和水平井钻井施工的难点，分析了该井主要技术难点，重点从井眼轨迹轨道设计优化、轨迹控制及施工技术措施和钻井液技术等方面对该井安全技术进行了全面的介绍，为今后同类井钻井提供可参考的经验。

Abstract:

SU77-5-8H is the first horizontal well crossing coal seam with high-inclination, by which development benefit was promoted for Shansi group23 in Su77 block of Sulige gas field. The upper part of target bed (Shanxi23) is structured by carbonaceous mudstone and cola seam in the thickness of 20～30 meters. Because of the specialty of coal-bearing stratum, collapsing occurs easily in drilling process, and this coal-bearing stratum is in deviation building section in front of target point with big construction difficulty and high risk. Analysis was made on the main technical points, and introduction was made on the safety technology about design optimization, trajectory control, construction measures and drilling fluid technique.