老168平台海油陆采丛式井钻井技术难点与对策

Cluster-well Drilling Difficulties in Lao 168 Platform and Countermeasures

老168丛式井组井眼密度大、防碰难度大、造斜点浅、大尺寸井眼定向斜井段长、裸眼段长、井斜大、位垂比值大,油气层保护要求高。针对以上施工技术难点,采用大井眼浅地层定向、优化井身轨迹控制、控制井径扩大率以及优化海水钻井液等关键性技术,使该平台上的69口井均达到了工程设计要求,油气显示良好,为以后开发滩海地区浅层油藏,实现海油陆采积累了经验。

Drilling cluster wells in Lao 168 platform encounters some problems, including high wellbore density, big bumper difficulty, shallow incline-making point, large size wellbore, long directionally deviating hole interval, long open wellbore, large ratio of horizontal displacement vs. vertical depth, and high requirement of reservoir protection. In this paper, some countermeasures against the mentioned difficulties are presented, including to orient shallow layer with large wellbore, to optimize wellbore-trajectory control, to control caliper-enlarging ratio, and to optimize seawater drilling fluid. These countermeasures have been applied to 69 wells in Lao platform. As a result, oil and gas show is better. This study provides some experiences for further developing shallow-layer oil reservoirs in shallow marine.