碳酸盐岩超深水平井复杂井眼条件下特殊完井工艺研究与应用

RESEARCH AND APPLICATION OF UNCONVENTIONAL COMPLETION TECHNOLOGY FOR ULTRADEEP CARBONATE HORIZONTAL WELLS UNDER COMPLEX BOREHOLE CONDITIONS

塔里木盆地碳酸盐岩储层具有压力敏感、安全密度窗口窄、易喷易漏、井控风险大等特点,自2012年下半年开始,塔中区块水平井井深大幅增加、水平段不断延长,受储层跟踪难、井眼轨迹不平滑、钻具托压严重等因素的影响,模拟通井管柱在裸眼段摩阻较大(甚至光钻杆也很难通过),给后期的试油完井作业带来了很大的挑战。文章正是针对"模拟通井时间长、管柱下入难、无法进行常规完井"的问题,提出了以斜坡钻杆与油管相结合的完井管柱为核心的特殊完井方案,优化配置了完井管柱,完善并标准化了该工艺的工序,成功应用5口井的效果分析表明,该工艺有效建立了复杂井眼条件下的油气通道,并为类似井的完井工程提供了一个新思路。

Carbonate reservoirs in Tarim basin are pressure-sensitive,having narrow safe density window,tending to have blowouts and lost circulations,the well control risk is rather high. Since 2012,with the sharp increase in horizontal well MD and the extension of horizontal intervals,the later well testing and completion is becoming more and more challenged by hard reservoir tracking, not-smooth well profile and serious backpressure on the BHA,the high drag along the open hole section affects the simulated drifting string,even the bare drill pipestring,to run in. Here in this paper an unconventional completion program using an innovative completion string combining slope-shoulder drill pipes and tubings is proposed,the matching process is also standardized. Its successful application in 4 wells has proved this process can establish effective oil passage when under complicated hole conditions,the well production can be improved,and it will provide a new way for completion engineering under complex well conditions