Design And Development Of MPD Control System Based On PCS7

With the exhaustion of petroleum resources,it is more and more difficult to explore and exploit oil.Conventional drilling technology has been difficult to meet the requirements of high efficiency drilling in complex formations,but this problem can be solved effectively by MPD technology.Therefore,a MPD control system is designed and developed based on PCS7 in this paper.And the advanced control technologies are researched and applied in MPD system.(1)Design overall scheme of MPD control system.On the basis of the principle of MPD technology,the technological process and technical characteristics of MPD is analyzed.Overall scheme of the control system is designed,and the overall design idea is put forward.The foundation of the following hardware and software design is laid.(2)Design hardware of MPD control system.Hardware components and functions are analyzed,and based on the control scheme,the flow chart of the pipeline instrument is designed.Based on the requirements of process and control,Automatic control instrument is selected,and I/O nodes its signal type are designed.And the problem of signal transmission between PLC and field instruments is solved by ET200 M.And the security of the system is enhanced by hard redundancy mode.Finally,a safe and stable MPD hardware system is designed.(3)Design software of MPD control system.Taking PCS7 as the software development platform,the hardware configuration is carried out in Step7.Wellhead back pressure control loop,micro flow control loop,standpipe pressure control loop are built by CFC and P&ID diagram.And normal drilling,connection,tripping mode programs are designed by SFC and SCL.The mudloss and overflow is treated by the method of adjusting control mode.And upper computer flow chart is designed in WinCC.On the basis of the OPC protocol,the data transmission between the hydraulic parameters software and MPD system is established.(4)Research on advanced control algorithm of MPD system.Because of the nonlinear characteristics of MPD object,the traditional control algorithm is difficult to meet the control requirements.On the basis of the research of fuzzy control and fuzzy PID control simulation based on Matlab,through the method for querying fuzzy control query table by off-line,the fuzzy controller and fuzzy PID controller are designed in PCS7.(5)Test system and analysis result.The experimental results of the system are analyzed.The experimental results show that the task of MPD can be completed effectively and the safety and efficiency of the drilling process can be ensured in the system.Overall,a MPD control system is designed and developed in this paper,and the application of advanced control algorithms are researched in the MPD system.The problem of safe drilling under the narrow density window can be effectively solved,and some reference value for the research of the MPD technology control system is provided.