为了解决陇东气田水平井钻井过程中井壁易失稳、机械钻速低、钻井周期长等技术难点,开展了水平井钻井技术研究.根据地层特点将水平井设计为三开井身结构,利用表层套管封固易塌易漏地层;根据靶前距要求并为了确保井眼轨迹平滑,设计采用五段制井眼轨道;针对不同井段的井眼轨迹控制要求,采用了相应的井眼轨迹控制技术;根据不同井段钻遇地层的特点,优选了个性化PDC钻头,优化钻井液性能并制定了相应的维护处理措施,形成了适用于陇东气田的水平井钻井技术.现场应用表明,陇东气田水平井钻技术能解决水平井钻井过程中存在的技术难点,实现提高机械钻速、缩短钻井周期的目的.%To tackle the challenges of wellbore instability,low rate of penetration and lengthy drilling time encountered in horizontal drilling in Longdong Gas Field,the investigation of horizontal drilling techniques was carried out.The casing program was designed as a three-spud structure according to the formation features,with the surface casing isolating the fragile formations;the well trajectory was designed as five sections to meet the target distance requirements and ensure smooth well trajectory;applicable well trajectory control techniques were used according to the well trajectory requirements at different sections;PDC bits and drilling fluid were optimized in line with the formation characteristics of the various well sections,and corresponding maintenance measures were taken,by which a set of horizontal drilling techniques applicable to Chengdong Gas Field were developed.Field application showed that the horizontal drilling techniques in Longdong Gas Field can solve the problems occurred in the drilling process,increase the rate of penetration and decrease the drilling time.
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