The Computer Control System Of Offshore Platform Seawater Treatment Process Based On DCS

One certain offshore platform takes the duty of seawater injection in the oil field, and the seawater treatment process of the offshore platform is the key to ensure petroleum exploitation in the sea. But the platform has some problems as follows:First, the seawater quality of the sea where the oil field is located is so special that it is difficult to make the treated seawater achieve the injection index. Second, the supply of seawater injection of the oil field is more than the demand, and the surplus is drained directly to the sea by circumfluence that makes seawater resources, energy resources and medicament for seawater treatment waste . And third, it is very difficult for the pumps to realize constant pressure injection because there is no distributing room for seawater injection in the sea.So, in order to resolve those problems above, this paper puts forward some proposals as follows: to establish the computer control system of offshore platform seawater treatment process based on DCS, the industrial programmable logic controllers(PLC) as the local control layers of the system are applied to control distributing units of the seawater treatment process, and to develop the relevant real-time computer monitoring and controlling system applied to the central control layer to realize all-sided monitoring and controlling for the seawater treatment process, and to realize dynamic simulation. And relevant data management system is developed to realize effective data management. In addition, in order to make the pumps realize constant injection pressure, the expert tuning PID VFVS constant injection pressure control sub-system for pumps is established and relevant software module is developed. The sub-system cancontrol automatically the quantity and rotate speed of the pumps running to realize the pumps optimum run according to the seawater injection plan of the oil field, which realizes constant injection pressure, energy saving and decreases the consumption to a large degree.The result of long-term operation shows that the computer control system is practical and effective, it can run in the optimal state within a long duration to fully realize data collection and process, remote data transmission and VFVS constant injection control of pumps. It speeds up the automatic procedures of the seawater treatment process, really realizes the unmanned working, decreases the physical intensity to a large extent, improves the management, enhances the management level, avoids equipment wear down as much as possible, makes the seawater treatment efficient and lessens the cost of production.