侧位抛物线大位移井轨道设计

Design of Lateral Parabola Extended-Reach Well Trajectory

优选井眼轨道是大位移井获得成功的关键之一。由于大位移井轨道的自身特点,进行轨道设计时,不仅要考虑摩阻和摩扭的大小,而且要考虑套管磨损和井眼长度以及施工的难易程度。提出了一种新的大位移井轨道即侧位抛物线轨道及其设计方法。计算分析表明:侧位抛物线大位移井轨道井眼长度、摩阻和摩扭均小于同条件下的二次抛物线和悬链线轨道,而且不需要圆弧过渡段,给设计和施工带来了方便,因此,侧位抛物线轨道要优于二次抛物线和悬链线轨道。与圆弧形轨道相比,侧位抛物线轨道的旋转钻进摩扭稍大,但其起钻摩阻和滑动钻进摩阻均小于圆弧形轨道,而且井眼长度比圆弧形轨道小得多;因此,侧位抛物线优于圆弧形轨道。除给出侧位抛物线大位移井轨道设计全部计算公式外,还给出了计算实例,对现场设计施工具有一定的指导意义。

To optimize trajectory is one of the key problems of the Extended-Reach Well(ERW). A new curve called lateral parabola is put forward. In the meantime, the design method of lateral parabola trajectory is provided. The relative calculation shows that the new trajectory has smallest torque & drag and shortest well length among the four trajectories. Both design equations and case history are also presented in this paper.