浅层大位移水平井轨迹控制技术

TRAJECTORY CONTROL TECHNOLOGY OF EXTENDED REACH HORIZONTAL WELL IN SHALLOW RESERVOIR

建页HF-1井由于靶前位移非常小,只有235.11m,造斜段进尺只有370m,不适合用悬链线等降低摩阻的轨道设计方法,因为这几种剖面都要求有相对较为充足的靶前位移才可实现。因此,将剖面类型选为单圆弧剖面(直-增-水平),这种剖面轨迹简单,减少了大斜井段稳斜井段进尺,增加了连续定向增斜进尺,能保证井眼轨迹平滑,同时减少了局部增斜和降斜井段,减小了钻柱与井壁接触面积,能有效降低全井摩阻和扭矩。在此基础上做出了比较符合现有施工条件的0.35°/m造斜率的井眼剖面。文章介绍了该井技术难点和施工经过,阐述了大位移水平井摩阻扭矩分析的重要性,对高摩阻产生的原因和如何避免进行了分析,对国内实施页岩气水平井的开发施工具有一定的指导意义。

For Jianye HF-1 well, the displacement is very small with only 235.11m, and the angle buildup interval is only 370m, so it is not suitable for the track method with catenary equal reduction friction, the reason is that these kinds of profiles are required to have a relatively sufficient displacement. Therefore, the profile types should choose the single circular arc profile (straight - add - level). For the track of the profile is very simple, it reduces the hole angle footages and increases the continuous building angle footages, can guarantee the smooth wellbore track, reduces the drill string contacting with the borehole wall, so can effectively reduce the drag and torque. On the basis of this, the profile with buildup rate of 0.35°/m was designed which was suited for existing construction condition. The technical difficulties and construction process of Jianye HF-1 well were introduced, the importance of the friction torque analysis of the extended reach horizontal wells was elaborated. The reasons producing the high friction drag were analyzed and its preventive measures were also proposed.