剑门1井超深超长小井眼钻井技术

剑门1井在第四次开钻中，用Φ215.9 mm钻头钻进中遇到了严重的井下复杂情况，被迫改变井身结构设计，油层套管提前下入，从而大大增加了Φ149.2 mm小井眼钻井的长度。由于井身结构的改变，把一些本该在第四次开钻前应解决的复杂地质问题留给了小井眼钻井阶段。加深的小井眼钻井难度一般都比较大，对于超深超长的小井眼钻井难度就更大。剑门1井在超深超长加深小井眼钻井中，针对面临的许多难题，制定了详细的施工技术措施：①将聚磺钻井液逐步转换为仿油基钻井液；②优选钻头型号和优化钻井参数；③使用顶驱钻井；④采用复合钻具，上部为Φ127 mm S135 18°钻杆，下部用Φ88.9 mm S135 18°钻杆钻井。最终安全顺利地完成了这口超深（7 009 m）超长（2 005.43 m）小井眼井段的钻井工作，取得了宝贵的小井眼钻井经验和丰硕的勘探成果。

Slim hole drilling technology used to deepen the ultra-deep well Jianmen-1

Upon the fourth spud in of the well Jianmen 1, serious and complicated downhole problems occurred in drilling with a 215.9 mm bit. The casing program had to be changed, and the production casing was run ahead of the schedule. The length of the 149.2 mm hole was thus largely increased. So the geologic challenges to be solved before the fourth spud in were left over to the slim drilling stage. Basically the deepening slim hole is hard to drill, and extremely harder in drilling ultra deep wells. Therefore for the deepening slim hole drilling on the well Jianmen 1 with the total depth of 7009 m and the slim hole length of 2005.43 m, we adopted technical measures as follows: ①to change the poly sulphonated drilling fluid gradually with the MEG drilling fluid； ②to optimize bit selection and drilling parameters； ③to use top drive system； ④to adopt composite drill string with the 127mm S135 18° drill pipe at the top, and the 88.9 mm S135 18° drill pipe at the bottom. The drilling work was carried out safely and smoothly, thus valuable experiences have been gained in slim hole drilling.