Abstract: Controlling the orientation of deviation by an application of the regularity of bit walkcan reduce the difficulty and the amount of the ework to control the bit trajectory,it can alsoreduce the frequency of turning azimuth and trips.It will cut down the drilling cycle,cutdown the cost of drilling and improve the quality of bit trajectory.Starting with the describedmodel for a drift trajectory,constraint equations about all parameters are established,and thesolution is found.A computer software using the rnethod to design a 3-D drift well-path hasbeen prepared,and the problem of designing a 3-D drift trajectory is solved.The method pre-sented in this paper applies to various well configurations,composed of straight lines andarcs.An example is tested and verified.

Key words: drilling theory, directional drilling, borehole trajectory, mathematical model

摘要： 利用方位漂移规律控制井斜,可以减少井眼轨道控制的难度和工作量,减少扭方位操作和起下钻次数.因此可以缩短钻井周期,降低钻井成本,提高井身质量.本文从方位漂移轨道的描述模型入手,建立了各参数间的约束方程,提出了求解方法,并研制开发了三维漂移轨道设计软件,从而解决了方位漂移轨道的三维设计问题.其设计方法适用于由直线和圆弧所组成的各种剖面,并通过算例进行了验证.

关键词: 钻井理论, 定向钻井, 水平钻井, 井眼轨迹, 数学模型