柯柯亚深层煤岩气水平井钻井实践
Drilling practices on horizontal wells of deep coal measure gas,Kekeya structure
赵前进 1杨立军 1李慎越 1任凯 1秦新德1
作者信息
- 1. 中国石油吐哈油田公司工程技术研究院 新疆哈密 839009
- 折叠
摘要
吐哈盆地侏罗系煤岩天然气区块位于山前高陡构造,地层倾角大,地质条件复杂,为国内陆地埋藏最深的煤岩气气藏,煤层水平井钻探技术在该领域尚属空白,钻井过程中"斜、慢、阻、卡"矛盾突出,亟须开展煤岩气水平井钻完井技术研究.为此,针对井身结构优化、井眼轨道优化、防斜打快技术、煤层坍塌机理、水平段安全钻完井开展了深入分析研究,柯新 1H先导试验结果表明:①大三层井身结构可以满足水平井安全钻进,但具有较大的优化潜力;②垂直钻井技术在 2 500 m以浅的煤上地层应用效果佳,为中上部地层防斜打快提供了技术手段;③技术套管下深的确定是关键,是保障水平段能否成功实施的基本条件;④水平段通过多靶点轨道设计、随钻岩性追踪、无扶单弯螺杆+缩小底部钻具外径、双向通井工具、强抑制强封堵钻井液等手段降低卡钻风险,在煤层起伏变化大的情况下,确保了千米长水平段钻进与下套管作业顺利实施.
Abstract
The Jurassic coal measure gas block in Tuha Basin is located in a piedmont high-steep structure with large formation dip and complex geological conditions.It is the coal measure gas reservoir onshore in China with the deepest burial depth.However,the technology of horizontal-well drilling is still blank in such reservoir,and there exist some prominent problems during this drilling,namely well deviation,slow ROP,drilling drag and sticking.It is urgent to study horizontal-well drilling and completion technologies for these sort of gas reservoirs.Thus,some studies were conducted from aspects of casing program and borehole trajectory optimiza-tion,deviation control and faster drilling techniques,and safe drilling and completion in horizontal intervals.A pilot test on KX1H well reveals that(i)the three-section casing program facilitates the safe horizontal-well drilling,while it can be further optimized;(ii)with better performance in some coal measure reservoirs less than 2,500 m in depth,the vertical drilling technology provides a means for deviation control while fast drilling in middle and upper strata;(iii)as a basic condition,to ascertain the casing setting depth is critical for success drilling in horizontal intervals;and(iv)such tools of multi-target trajectory design,tracking lithology while drill-ing,single-bending screw drilling without centralizer + shrinking out diameter of BHA,bi-directional pigging means,and high-inhi-bition and high-plugging drilling fluid can be used to reduce sticking risks in these intervals,thereby to ensure casing while drilling in good order in those horizontal intervals over 1,000 m.
关键词
深层煤岩气/坍塌机理/井身结构/防斜打快/技套下深/安全钻井Key words
Deep coal measure gas/Collapse mechanism/Casing program/Deviation control while fast drilling/Casing setting depth/Safe drilling引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据