煤层气水平井无导眼地质导向钻进技术

针对目前松软煤层水平段成孔困难、煤层钻遇率较低以及造斜段钻进过程中需要施工导眼井等问题，采用地质导向与几何导向相结合模式，对井身结构优化、钻进参数优选、防塌钻进、多标志层地质导向钻进、水平段井眼轨迹精细化控制等进行研究。在沁水盆地成庄煤矿进行现场应用，钻完井施工顺利，3口水平井都实现无导眼直接一次着陆入靶，水平煤层段累计进尺1 604.72 m，煤层钻遇率达到100%，最终水平段下入PE筛管总长度1 366 m。完善了煤层气水平井钻完井工艺，为煤层气低成本高效开发钻井施工提供技术借鉴。移动阅读 

Geosteering technology and CBM horizontal well drilling without pilot hole

Aiming at the difficulties of hole-forming of the horizontal interval in a soft coal seam,low drilling ratio of coal seam and need of pilot hole during deflecting drilling,the key technologies such as drilling parameter optimization,anti-collapse drilling were put forward in the paper.Geosteering technology with multi-markers was used to realize timely layer identification,to search suitable targeting angle,to be adaptive to the stratum dip so as to realize one time direct landing at the target.Geosteering and geometric steering were combined to control finely the wellbore trajectory of the horizontal interval,to make the wellbore trajectory smooth.Three horizontal wells were drilled in Chengzhuang coal mine,the accumulative footage in coal seam was 1604.72 m,drilling ratio of coal seam was 100%,and the final horizontal section into the PE screen had a total length of 1366 m.The study can improve drilling and completion technology of CBM horizontal wells,provided a new approach for low cost and efficient CBM development.