Research On Trajectory Control System Of Kilometer Directional Drilling Machine

The directional drilling technology of coal mine is developed in the field of petroleum drilling,which has been widely used in geological exploration of coal mine,gas drainage,water damage prevention and other fields by virtue of its excellent properties such as deep drilling depth and controllable trajectory.The existing drilling trajectory control is mainly completed by relying on the driller's construction experience,which inevitably leads to problems such as low drilling efficiency and large deviation degree between the actual trajectory and the designed trajectory.In order to improve the efficiency of coal mining and realize the intelligent control of drilling hole trajectory,it is necessary to carry out the research on trajectory prediction and control technology of horizontal directional drilling machine in coal mine.Trajectory control of directional drilling means to track the designed trajectory,and its premise is to accurately predict the trajectory of the next stage.Based on the calculation principles of various borehole trajectory prediction methods at home and abroad,this paper discussed their applicability in the field of coal mining.In order to achieve trajectory prediction,the precondition is to define the current attitude of the drill string and the current position of drilling track,therefore,this paper studied the calculation method of the attitude parameters of the drill string and the description method of the drilling track on the hardware and software level respectively.Secondly,a trajectory prediction algorithm suitable for near-horizontal directional boreholes in underground coal mines was constructed in this paper according to the existing methods of borehole trajectory prediction,including the method of vertical and horizontal bending beam and the method of three points,the trajectory prediction algorithm calculated the unknown three dimensional coordinate values of the measuring point of the next drill pipe under different construction parameters by using the known attitude angle parameters and drilled hole trajectory parameters.In the end,based on the above trajectory prediction algorithm,this paper built the drilling trajectory control algorithm by using the method of derivative function and the principle of minimum tracking deviation.This algorithm took the three dimensional coordinate values of the next measuring point in the design trajectory as the input,and the optimal construction parameter of the following drill pipe as the output,with which the drilling rig can carry out the construction,so as to make the actual drilling trajectory as close as possible to the design trajectory and achieve the optimal trajectory control.On the verification of the above two algorithms,this paper first verified the effectiveness of the trajectory prediction algorithm based on the actual drilling trajectory data,and completed the measurement of relevant parameters through experiment,realizing the drilling trajectory prediction based on the traditional vertical and horizontal bending beam method,compared the prediction accuracy of two methods,the results show that the trajectory prediction algorithm proposed in this paper is not only easy to implement,but also slightly better than the traditional vertical and horizontal bending beam method.Secondly,the validity of the trajectory control algorithm was verified by field drilling experiments,due to the trajectory prediction algorithm did not consider the influence of stratum factors in the calculation process,in the final trajectory control effect comparison,rely on the control algorithm was slightly weaker than the construction rely on the driller's experience in construction workers,but this did not mean that the trajectory control algorithm has no application value,in the context of smart mines,for the coal mining automation and intelligent,the work was still of great significance.