工具面角的精确设定在轨迹控制中的应用

Pratical Use of Toolface Setting in Trajectory Controlling

在定向钻井中,由于直井段井斜失控或位移朝同一方向累积,时常会遭遇水平位移超标。严重的水平位移超标对超深井、丛式井、水平井危害极大,为此,提出了更科学灵活的工具面控制方法,在初始定向时以井底方位为基准,依据斜面法扭方位原理,使实钻轨迹按照实际设计的轨迹进行,当接近设计方位时再把工具面对准设计方位。在小度数井斜下设定磁性工具面能对井斜角和方位角达到精准的控制,从而达到轨迹的精细控制。该方法经过大量现场实践,取得了较好的应用效果。

It is common to face excess horizontal displacement caused by excess inclination or accumulation during directional drilling. Excess horizontal displacement could be extremely harmful in drilling of ultra-deep wells,cluster wells and horizontal wells. Therefor,it should be handled by hole straightening,bypassing or kicking off in advance. In the early stage of kicking off,magnetic toolface is normally set according to the design. In this kind of situation,wellbore inertia will lead to the lag of trajectory adjustment,affect the drilling efficiency and trajectory quality,and may even lead to downhole complex situations. Therefore,a more scientific and flexible toolface setting method is proposed. The latest measured azimuth is taken as reference at the beginning during kicking off,and the actual drilling trajectory is carried out as design according to the principle of inclined plane torsion orientation. And set the toolface back to design when the measured azimuth is finally close to design. Setting magnetic tool surface in small degree well deviation can achieve accurate control of well deviation angle and azimuth angle,so as to achieve fine control of trajectory. Through a lot of field practice,this method has achieved good application effect.