摘要
川东北元坝气田是西南地区重要的天然气生产基地,随着勘探开发的深入,其三叠系上统须家河组及以上陆相地层表现出良好的开发潜力。为增大储量控制面积,提高单井产量和降低布井密度,在该地区部署了一批开发评价水平井。但该区陆相地层因地层压力系统复杂,气层多且薄,岩石可钻性差以及砂、泥岩互层频繁等客观因素的存在,使得钻井施工和井眼轨迹控制困难,严重制约了该区天然气的勘探开发步伐。结合工区地质环境特征,对陆相地层钻井施工及井眼轨迹控制存在的问题和难点进行了深入分析,并阐述了井眼轨迹控制的影响因素,从剖面优化设计、钻具组合优选、造斜段和水平段控制等方面进行井眼轨迹控制方法研究。结合工区内的YL704H井的成功钻探,验证了井眼轨迹控制方法的适用性。通过以上研究和实践,最终给出了一套适合川东北元坝陆相地层的井眼轨迹控制方法,该方法能为研究工区水平井的钻探和研究提供依据,也可以为缩短钻井周期、节约钻井成本、减少井下事故,以及最终实现该区水平井安全、高效建井提供帮助。
Sichuan Yuanba gas field is an important production base in Southwest China. With in- depth exploratory development,the upper Triassic Xujiahe formation and above terrestrial formation have good potential for development. Numbers of horizontal wells have being deployed in this area to increase controlled reserves,raise individual well producing rate and decline well density. However,the drilling and well path control are difficulty in terrestrial formation of Yuanba area,it severely restricts gas exploratory development because of the complex formation pressure system,thin gas bearing reservoir,poor drillability and frequent sand and mudstone alternate layer.Combined with geological environment of Yuanba area,the problems and difficulties existent in drilling and well path controlling in terrestrial formation were analyzed,the factors of influencing well path control were described,the methods of well path control were researched from the aspects on optimal design of section,optimization of BHA,and controlling of deflecting section and horizontal section. The well path control methods have been used successfully in well YL704 H. And the corresponding well path control methods suited for Yuanba terrestrial formation has been summarized. The methods not only can provide a basis for horizontal drilling,but also can be helpful for shortening drilling cycle,saving drilling cost and decreasing downhole accident.
出处
《钻采工艺》
CAS
北大核心
2014年第6期30-34,2,共5页
Drilling & Production Technology
基金
国家自然科学基金项目(编号:51474185)
国家重点基础研究发展计划(973)项目(编号:2013CB228003)
关键词
陆相地层
水平井
井眼轨迹
控制方法
川东北
元坝地区
terrestrial formation,horizontal well,well track,control method,Sichuan Yuanba area
