基于熵权法的大位移井井眼轨迹设计方案优选

Selection of extended reach well trajectory design scheme based on entropy weight method

井眼轨迹设计对大位移井安全高效钻井作业的实现极为重要。大位移井钻井存在长裸眼段井壁稳定性差、摩阻扭矩高、管柱屈曲严重、井眼清洁难度大等问题,井眼轨迹设计需要对其进行综合分析与评价。基于熵权法构建了大位移井轨迹设计方案评价模型,充分依据评价指标的数据本身波动情况计算权重与方案得分,实现了大位移井井眼轨迹设计方案的定量评价,并在某油田大位移井钻井作业中得到了成功应用。该研究不仅为大位移井轨迹设计方案优选提供了新的思路与指导方法,也为后续开展大位移井钻井技术优化与风险评估提供了技术参考。

The trajectory design of extended reach well is quite important for its safe and efficient drilling.The drilling of extended reach well faces several problems,such as poor wellbore stability in the long open hole section,high torque and drag,serious string buckling and difficult hole cleaning,so its trajectory design needs comprehensive analysis and evaluation.In this paper,a model for evaluating the trajectory design scheme of extended reach well was established based on the entropy weight method,in which the weights are calculated and the schemes are scored by making full use of the fluctuation of evaluation indexes,so that the trajectory design scheme of extended reach well is quantitatively evaluated.It has been successfully applied to the drilling of extended reach well in one certain oilfield.This research not only provides a new idea and a guidance method for the selection of trajectory design scheme of extended reach well,but also a technical reference for the subsequent drilling technology optimization and risk evaluation of extended reach well.