南海流花超大位移井井眼净化技术

为适时监测井眼环空净化状况,结合国内外最新研究成果,建立了一套大位移井井眼净化监测和计算方法。该方法可将立管压力转换为循环钻井液当量密度(ECD),做出实测ECD曲线、理论环空无岩屑床ECD曲线和理论环空存在一定厚度岩屑床ECD曲线,通过对比分析,实现对环空井眼清洁程度进行监测,并对环空平均岩屑床厚度进行定量评价。利用该方法对南海Liuhua 11-1-17 B3ERW 4井进行了计算分析,研究结果与实际情况相吻合。计算结果表明,在整个钻进过程中不同井段均有岩屑床形成,其中?444.5 mm(特别是井斜角大于45°)的井段,所形成的岩屑床高度均为最高,是大位移井中携岩最困难的井段。该计算方法简单实用,可以对环空岩屑床的形成进行监测,并能给出环空平均岩屑床高度的范围,为现场施工提供指导。

BOREHOLE CLEANING TECHNOLOGY FOR MEGA-EXTENDED-REACH WELLS AT LIUHUA FIELD IN SOUTH CHINA SEA

To monitor the hole-cleaning condition and provide guidance during drilling,A new approach is proposed to monitor the hole cleaning condition and calculate the height and position of cuttings bed in extended-reach-wells.This approach was used to calculate and analysis the case of Liuhua 11-1-17 B3 ERW4 well.The calculation coincided with the actual conditions well,which showed that the approach in this study was workable and valuable in drilling engineering.At the same time,the study result indicated that cutting-beds with different heights existed during all drilling phases and the segment where the hole size was ?444.5 mm and the hole inclination was more than 45 degree had the highest cuttings-bed and became the most difficult segment for cuttings transport.The approach is simple and applied,thus providing guidance for field operation.