中文摘要：

为解决自动防斜垂直钻井系统在井下纠斜时纠斜方位难以准确控制的问题，开展了垂直钻井系统井下纠斜力连续控制的研究。在不改变钻具组合、元件和参数的前提下，建立了钻具导向纠斜机构机电液系统的动力学模型，推导出控制元件二位二通电磁阀在钻杆一个旋转周期内的通断时间与机构输出纠斜力的幅值及钻杆转速之间的函数关系；根据钻杆转速确定脉宽周期 T ，再根据目标纠斜力计算出电磁阀的断电持续时间Δt，在脉宽周期 T内让电磁阀断电Δt ，即可使纠斜机构输出预期的纠斜力。结果表明，试验模拟钻杆转速为65 r／min ，在1个脉宽周期内对电磁阀分别断电50，60或70 ms时，液压缸目标控制压力（即纠斜力）分别稳定在7.0，5.0和3.5 M Pa左右。研究结果表明，采用脉宽调制控制方法调节自动垂直钻具的井下纠斜力，能将纠斜力控制在稳定的目标值。

英文摘要：

For an automatic vertical drilling system ,it is difficult to accurately control the anti‐devia‐tion azimuth downhole .Therefore ,a study was conducted on the continuous control over downhole anti‐de‐viation force of the drilling tool .T he dynamical model of the mechanical‐hydraulic system for the anti‐devi‐ation mechanism was established ,without changing the tool structure ,component and parameters .Using the model ,the function relationship between the on‐off time of the two‐position two‐way solenoid valve in a moment of one revolution of the drill pipe ,the amplitude of the output anti‐deviation force of the mecha‐nism and the rotary speed of the drill pipe was derived .To obtain an expected anti‐deviation force output by the anti‐deviation mechanism ,the duration time Δt for switching off the solenoid valve was calculated by the target anti‐deviation force ,and the pulse width cycle T that determines the Δt was determined by the rotary speed of drill pipe .Accordingly ,the target control pressure of the hydraulic cylinder was respectively stabilized at 7.0 MPa ,5.0 MPa and 3.5 MPa in the experiment when the rotary speed of the drill pipe was set to 65 r/min and the solenoid valve was switched off for 50 ms ,60 ms and 70 ms respectively in one PWM cycle .The results showed that the downhole anti‐deviation force of the automatic vertical drilling sys‐tem could be stabilized at an expected range by PWM control .