关键词: 钻井理论, 数学模型, 井眼轨道, 设计计算, 定向井, 水平井, 大位移井, 多目标井

Abstract: During the process of directional drilling,the direction of well trajectory and its change are key parameters to monitor and control a well trajectory.As an important part of monitoring and controlling a well trajectory,the path-correction planning is generally required to reach a desired direction at its target.According to the characteristics of directional drilling technology,a three-section profile with two planar turns and one straight line is constructed in this paper to solve the problem on path-correction planning with the given direction in theory,which lays a foundation for effectively monitoring and controlling a well trajectory.The solving process of the design method proposed in this paper is uniform convergent due to avoiding solving the constraint equations set.All of the formulas are theoretically exact solutions,so the universal significance,computational accuracy,stability and convergence have been fully guaranteed.This method can be widely applied to planning directional wells,horizontal wells,extended-reach wells and multiple target wells while drilling.

Key words: drilling theory, mathematical model, wellbore trajectory, design calculation, directional well, horizontal well, extended-reach well, multiple target well