Abstract: It is necessary to scientifically plan and survey well bore trajectories in directional drilling.In order to describe well bore trajectory,a certain mathematical model should be used.At present,the popularly used trajectory models are the cylinder helix and spatial arc all over the world.The key parameters for monitoring and controlling well trajectory include the rates of inclination change and azimuth change.The conventional models for well trajectory cannot directly give an expression to the requirement for the change rates of inclination and azimuth.According to the characteristics of rotary steering drilling,a 3D model with universal applicability was proposed in this paper.This model is applicable for planning and surveying all kinds of well trajectories for the slant well,directional well,extended-reach well and horizontal well,and especially available to design the well profiles with combination of arc and straight sections in the vertical expansion plot.

Key words: rotary steering drilling, well bore trajectory, design method, directional well, horizontal well, extended-reach well, mathematical model

摘要： 井眼轨道的设计与监测技术一直是定向钻井中的研究热点.为了描述和计算井眼轨道,须建立一定的数学模型,目前国内外普遍采用的井眼轨道模型是圆柱螺线模型和空间圆弧模型.然而,井眼轨道监控中的核心参数是井斜变化率和方位变化率,但以往的井眼轨道模型却不能直接反映出对它们的需求.针对旋转导向钻井的特点,提出了一种具有通用性的三维井眼轨道模型.该模型适用于由直线段和圆弧段所组成的各种井身剖面,可广泛应用于斜直井、定向井、水平井、大位移井的设计与监测.

关键词: 旋转导向钻井, 井眼轨迹, 设计方法, 定向井, 水平井, 大位移井, 数学模型