Design Of Elevating Control System Of Jack-up Platform

With the oil and gas exploitation developed from the land to the sea today,the jack-up platform becomes the most popular platform in offshore oil and gas exploitation and service support because of itsadvantages of high flexibility,reliability and low cost.It is applicable to maximum 150 meters water depth and drill more than 9000 meters.The major domestic offshore industry manufacturers and drilling equipment manufacturers have invested their efforts to develop the elevating system which is the key equipment of jack-up platform.This thesis is based on the development of a rack and pinion elevating system for a jack-up platform,which is suitable for 400 ft depth.Based on the working conditions of elevating system of jack-up platform,this paper first determines the distributed structure of the control system,designs the measurement method of the key processing variables,and analyzes two driving schemes of the motor.The torque transducer and the auto-Transformer is used to control the output of the lifting system pinion' torque.Then,the elevating control system software,the torque reallocation and the operation method and the rack phase difference computation and implementation method are designed.According to the elevating control system overall scheme,the sensor calibration method,system alarm,system protection,emergency stop function and key operation method are proposed.And the critical processing value of the system is provided according to the engineering experience.The ETAP software is used to analyze the electrical distribution of the elevating control system.The total power of the system is 2.254 MVA determined by using Newton-Raphson method.The short circuit current is calculated by the IEC61363-1 method.The results are used for the jack-up platform power system Protection Coordination and the elevating control system generator Protection CoordinationFinally,this paper puts forward the performance test method of elevating control system according to elevating control system experiment method and current standards.And FMEA method is used to evaluate the root causes,treatments,frequency,observability and consequences of each failure situation according to all the situations encountered in the operation of the elevating control system.The system has been installed and tested successfully.This is the first evelating system of jack-up platform applicable to 400 ft warter depth.It fills the blanks of China and is of great importance for localization of jack-up platform.