渤海油田表层大尺寸井眼预斜技术探索与应用

为了解决丛式井加密调整的防碰问题,在浅部地层大井眼井段寻找间隙,将造斜点上移是有效手段。以A17井为例,通过合理的槽口分配,轨迹优化设计,大尺寸马达的“量身定做”及参数优选等探索研究和实施。结果表明:①利用外排槽口实施大位移井,可以减少防碰压力;②采用拟悬链线设计的井眼轨道更优,更有利于大位移井的实施;③优选1.75°弯角,扶正器套657 mm满足造斜需求,最大造斜率可达4°/30 m;④660.4 mm井眼一趟钻施工方式可实现0.42 d的工期缩减,实现50余万元的费用降本。以上成果认识,为渤海油田丛式井加密调整提供新的技术手段。

Exploration and Application of Preventive Oblique Technology for Large-scale Borehole in Surface of Bohai Oilfield

In order to solve the problem of anti-collision in dense adjustment of cluster wells,it is an effective means to find clearance in large wellbore section of shallow formation and to move the deviation point.Taking well A17 as an example,the reasonable slot allocation,trajectory optimization design,tailor-made large-size motor and parameter optimization were explored,studied and implemented.The results showed that:①The application of extended reach wells with outflow slots can reduce the anti-collision pressure.②The well trajectory designed by quasi-catenary is better and more conducive to the implementation of extended reach wells.③The optimum 1.75 degree bend angle is selected,and the centralizer sleeve 657 mm meets the deviation requirement,and the maximum deviation rate can reach 4 degrees/30 m.④The construction period of 660.4 mm well can be reduced by 0.42 days by one drilling.We will reduce the cost by more than 500000 yuan.The above results provide new technical means for infilling adjustment of cluster wells in Bohai oilfield.