Fundamental Research Of WOB Drilling Pressure Prediction Control

During drilling, constant pressure automatic drilling system is mostly adopted to adjust the drill press. Traditional automatic drilling control system has simple structure, reliable and stable characteristics, but it often cannot effectively overcome load and drilling parameters of a wide range of change and the influence of nonlinear, so the automatic drill is difficult to achieve accurate control in the time-varying, time-delay and nonlinear systems, not meeting the drilling requirements.Aiming at the shortage of traditional automatic drilling control system at present, putting forward automatic drilling control system based on the prediction of drilling pressure. First, the thesis uses time series and grey system theory respectively establish the drilling prediction model. Then combine with the actual drilling data to verify the accuracy of the model and compare the two kinds of model. The results show that grey model as higher accuracy and stronger applicability. Using the grey forecasting model weaken the system’s nonlinear disturbance, establish a decision-making body to meet the certain constraint condition, and then add the drill pressure prediction model and the decision-making body to automatic drilling control system. Finally, WOB forecast automatic drilling system is designed.Finally, simulation and analysis the drilling pressure prediction automatic drilling control system based on the relevant real drilling data of Qinghai region in the MATLAB/Simulink environment. The results show that the drilling pressure prediction automatic drill control system based on the theory of the grey realizes the function of control in advance, compensates the error, reduces the overshoot, and can apply to the nonlinear, lag control system.