多靶浅层水平井轨迹控制及尾管柱下入技术

Techniques of trajectory control and liner running-in of the shallow multi-target horizontal well

为确保井眼轨迹在油层内有效运移,bTHW404井水平段随油层的起伏而起伏,钻穿6个目标靶点,是"鱼钩"状多靶水平井。该井的主要施工难点是:靶区油层薄,靶窗范围小,要钻穿6个目标靶点,轨迹精度要求高;井眼轨迹上下起伏,入井钻具摩阻大,加上垂深浅、钻具轻,钻压不能有效地传递;水平段的起始点处于整个轨迹的最低位置,在此处易形成岩屑堆积,影响完井管柱下入。施工时,精确地控制井眼轨迹、优化钻具结构、优选钻井参数,采取多种措施保证割缝尾管的安全下入,仅用53 h就完成了bTHW404井水平段钻进和尾管的下入,为今后同类型井施工提供了经验。

To ensure the effective well trajectory in the oil zone, the horizontal section of the bTHW 404 well fluctuates with the oil zone to make through six target points, and the well trajectory shapes like a ＂fish hook＂. The difficulties in the well are as follows： the oil zone is thin, the target window is small, there are 6 targets points, and thus the controlling accuracy of the trajectory is required high, the horizontal section fluctuates, the friction between drilling pipe and hole wall is high and the vertical depth is shallow, thus it is difficult to get enough WOB （weight on boat）, the vertical depth of the start point horizontally is the smallest where the cutting bed influences the pipe or liner running-in. During operation, multiple measures are adopted to ensure the secure running-in of slotted liner, such as the exact control of well trajectory, the optimization of drilling tool structure and parameters. It only spends 53 hours on fulfilling the drilling in horizontal sections and the running of liner in the well, providing good reference to similar projects.