水平井BHA控制井斜与方位机理及影响因素分析

Analysis of the Theory and Influence factors for the BHA to Control Inclination and Azimuth in Horizontal Well

根据间隙元法对水平井中各类钻具在不同钻井参数、不同井深和井斜条件下的受力变形计算结果，论述了水平井ＢＨＡ控制井斜与方位的机理是由下部钻具与井壁的不同接触状态来实现的。在转盘钻井时，ＢＨＡ控制井斜与方位是由近钻头稳定器与井壁的接触方位角、接触反力及摩擦阻力综合作用的结果；而在定向钻井中，是由动力钻具弯外壳与井壁的接触角和接触反力作用的结果。同时，对影响下部钻具与井壁接触状态的三类因素（井身形态、钻井参数、下部钻具结构）进行了分析讨论，为水平钻井中合理选择钻具组合和钻井参数、实施井斜与方位控制提供了理论依据。

The theory of the BHA to control inclination and azimuth deals with the different contact state between BHA and hole wall, according to the force and deformation calculation for various BHA at different drilling parameters, well depth and inclination by means of gap element method. In rotary drilling, the control inclination and azimuth is the result that the contact angle, force and resistance act as between the near stablizer and hole wall. In motor drilling, the control is the result that the contact angle and force act as between the bent tublar and hole wall. Meanwhile, the three influence factors (well shape, drilling parameters and BHA) are analyzed so as to select better BHA and drilling parameters and provide the theory basis for the control of inclination and azimuth in horizontal well.