Real Time Prediction And Control Of Directional Well WOB

In the process of drilling,most of the current use of constant WOB automatic drilling PID control system.The traditional PID control system has the characteristics of simple structure,reliable and steady,but it often can not effectively overcome load,drilling parameters of change in a large range and nonlinear effects,but also to PID controller of proportional coefficient,integral coefficient and differential coefficient is difficult to determine the past,but driller can only be empirically determined.PID adjust the parameters once determined,is constant,but the actual conditions in the drilling process is complicated,it is difficult to determine if the change regulation of PID parameters cannot meet the requirements of actual working conditions.Aiming at the shortcomings of automatic drilling PID control system,put forward the automatic drilling Fuzzy control system.According to the time delay problem of automatic drilling,the WOB on Application of grey prediction system,advance error compensation,reduce overshoot.combined with the actual drilling data,using grey system theory established WOB prediction model,by using the forecast model,established to meet certain conditions of the prediction and decision-making mechanism,the WOB prediction decision mechanism added to the automatic drilling Fuzzy control system.Finally,in the MATLAB/Simulink environment,the WOB prediction automatic drilling Fuzzy control system are simulated and analyzed.The results show that the drilling pressure prediction automatic drilling Fuzzy control system can be used to compensate the error and reduce the overshoot,applicable to nonlinear,time-delay,time-varying automatic feed drilling system of control.