苏里格气田苏5-1H井大井斜套管内垂直向上开窗钻井技术

苏里格气田苏5-1H井是国内第一口井斜超过80°垂直向上开窗井，施工作业面临有线仪器、斜向器下入较为困难及铣锥受重力作用、垂直向上不易开出窗口等技术难题，但该井仅用了19 h便垂直向上开窗成功。为此，总结了大井斜垂直向上开窗施工作业要点：①一次性斜向器开窗侧钻方法有利于垂直向上开窗侧钻；②采用复合式铣锥可一次性完成开窗及修窗作业；③强化斜向器坐封、定向侧钻的井眼准备措施；④细化套管开窗施工作业参数。该井用时6 h即完成2.5 m进尺，返出大量粗丝状铁屑，12 h后见大量泥砂及水泥，判断已开窗成功，反复修窗后起钻，优质高效地完成了整个高难度开窗任务，其施工作业要点可供今后同类型井借鉴使用。

A vertical casing exit operation in the high inclination cased hole of Well Su 5 1H,Sulige Gas Field

Well Su 5 1H in the Sulige Gas Field is the first well having vertical casing exit operation conducted in the wellbore with an inclination angle of over 80° in China, with such challenges as difficult running in of wireline instruments and the whipstock or hard vertical casing cutting due to the gravitational force on the cone mill bit. After overcoming such difficulties, however, we have devoted only 19 hours in one trip to successfully cut a casing window in the end. After 6 hours of casing cutting, 2.5 m footage was finished and lots of iron cuttings were observed. Then, after 12 hours of continuous working, a large amount of sand and cement were seen, from which a successful casing exit operation could be announced. Finally, the BHA was then tripped out after window trimming was done for several times. From this successful experience, a few good lessons are drawn herein. (1) The one time whipstock is helpful for the vertical casing exit, and the double cone milling bit can finish the casing window opening and trimming in one trip. (2) Good reparations for whipstock setting and casing exit job are vital in the whole process. (3) Each operating parameter at every step is well designed. All the above will provide good reference for the casing exit operation in similar wells.