苏53-78-71H 井造斜段井眼轨迹防碰设计与控制

Anti-collision design and control of borehole trajectory of building-up section of Well Su 53-78-71H

杨晓峰

YANG Xiaofeng

中国石油长城钻探工程有限公司

CNPC Greatwall Drilling Company, Panjin, Liaoning 124010, China

苏53 区块位于苏里格气田的西北部，每年钻成大量的水平井。该区块水平井大部分目的层设计在石盒子组气层， 造斜段需要穿越石千峰组和石盒子组的泥岩，地层易漏和垮塌，导致井下施工困难。苏53-78-71H 井位于该区块，造斜段先后侧钻4 次，钻成5 个井眼，特别是侧钻4 井眼的防碰设计和施工难度大，在该区块尚属首次。从侧钻4 井眼的侧钻位置选择、待钻井眼曲率设计、与原井眼的分离和其他井眼的防碰设计等方面进行了阐述、并在施工中从井眼轨迹控制、侧钻后定向段轨迹的防碰施工、入靶垂深的精确控制3 方面进行了技术控制，保证了井下作业的安全施工，实现了精确入靶。

Located in northwestern part of the Sulige Gasfield, Block Su 53 has many horizontal wells drilled every year. The majority of horizontal wells drilled in the block target gas-bearing layers in Shihezi Formation, so their building-up sections often need to drill through mudstone in Shiqianfeng Formation and Shihezi Formation which are likely to have lost circulation and collapsing, with frequent downhole complications. Well Su 53-78-71H drilled in the block contains 5 boreholes formed in 4 side-tracking operations in the building-up sections.The anti-collision design and implementation of the No. 4 sidetracked borehole is especially difficult, which is unprecedented in the block. In this paper, selection of optimal side-tracking position, design of borehole curvature to be drilled, separation from existing boreholes of No. 4 borehole, and anti-collision design of other boreholes have been reviewed. Borehole trajectory control, anti-collision measures in directional drilling sections after side-tracking and accurate control over vertical landing depth in target formations have been studied to ensure safety of downhole operation and accurate landing into the target formation.

10.13639/j.odpt.2016.05.004