Date of publication xxxx 00, 0000, date of current version xxxx 00, 0000.

No abstract

The deviation correction trajectory of the mechanical vertical drilling system (MVDS) is very important because it is the final embodiment of performance. However, it is impossible to obtain it at the design stage, except when using simulation methods. In this paper, tool face angle model and other theoretical models were established, respectively, and the trajectory simulation method was created through model coupling. Next, the method was used to simulate the trajectory of MVDS under two typical working conditions. The results indicate that the critical deviation angle is the deviation control accuracy of the MVDS. The existence of critical deflection angle makes MVDS correct deviation and change azimuth at the same time, resulting in the trajectory being a three-dimensional curve, which has the tendency of drifting to the left. Furthermore, the deviation and azimuth change rate are constantly changing in the process of drilling. The results also show that the MVDS is unable to correct the horizontal displacement of the downhole. The proposed method and analysis results are helpful to find out and solve the problem of the current design as soon as possible, and to provide guidance for the subsequent structure optimization.

The utilization of the adjusting device has been shown to significantly enhance the precision and stability of the mechanical vertical drilling tool. However, the inappropriate size of the structural parameters of the adjusting device will greatly affect its performance. Therefore, further improvements are necessary in order to optimize its performance. In order to achieve this, a thorough examination of the working principle and the various factors that influence the adjusting device is crucial. Through simulation and experimental methods, the function of the adjusting device was evaluated and potential solutions for the negative adjusting torque were proposed. By selecting appropriate values for the influencing factors, a more desirable adjusting torque with a reduced range of negative values can be obtained. Through a comparative analysis, the difference before and after optimization was evaluated. Furthermore, it was determined that the negative adjusting torque was caused by a reflux, primarily due to the diameter of the inlet and the flux area of the lower orifices. After optimization, the range of the adjusting torque that was beneficial to the adjusting device was extended to 15°~0°, providing a practical application in the drilling industry and serving as guidance for further optimization of the mechanical vertical drilling tool.