Abstract: A kind of rotary steering stabilizer used in a common rotary bottom hole assembly to control well path was developed.In order to develop and use this kind of bottom assembly,the mathematical models for 3D mechanical analysis of bottom hole assembly (BHA) with small deflection were proposed.The mathematical models include (1) differential equations; (2) boundary conditions of drill bit,stabilizer,bend angle,diameter change,tangent point and borehole wall; (3) models for calculating lateral forces and deflection angles of bit; (4) models for determining navigation ability and navigattion parameters.As an example,a given rotary steering bottom hole assembly was studied.

Key words: rotary steering bottom hole assembly, rotary steering stabilizer, mathematical model, drill string mechanics

摘要： 在普通旋转钻具的基础上,研制了一种旋转的近钻头稳定器,它可以将钻柱稳定在井眼截面的需要位置,以控制井眼轨道.为了研制和应用这种新钻具,建立了适用于该种旋转导向钻具进行三维小挠度静力学分析的数学模型,包括:①微分方程;②钻头、稳定器、变截面、切点和井壁的边界条件;③钻头的侧向力和钻头转角;④钻具的导向能力与偏心距和偏心方向.给出了一种旋转导向钻具的受力状态分析、井眼曲率预测及确定导向稳定器运行参数的计算实例.

关键词: 旋转导向钻具, 钻头稳定器, 数学模型, 钻柱力学