Study On Real-time Monitoring And Evaluation System For The Cathodic Protection Status Of Offshore Platform

Offshore platform is an important operation facility of offshore oil development. The environment of its location is extremely severe, and its serving time is very long. Therefore it is very important to effectively monitor and evaluate the cathodic protection status of offshore platform for guaranteeing the normal operation and production of platform and avoiding the hidden danger. There is several shortages of some existent monitoring systems applied to the cathodic protection of several platforms: (1)The corrosion protection evaluation from experts according to the international rules is not concrete; (2)The system cannot effectively show the whole cathodic protection status of offshore platform; (3)The system doesn't support the technology of virtual scene simulation. Therefore, the aim of this thesis is to develop a real-time monitoring and evaluation system which includes the application software and hardware equipment. This system can effectively monitor the cathodic protection potential of offshore platform, and can correctly evaluate the whole corrosion protection status of platform based on the monitoring data.The level of the protection potential at the exterior of the offshore platform with the cathodic protection system has a direct relationship with protective effect of the steel structure. Therefore, the developed Visual OPCP system plans to collect the protection potential and give an effectively evaluation of the whole corrosion protection status. The system has four function modules: virtual scene simulation monitoring module, real-time curve monitoring module, data collection and management module, and cathodic protection evaluation module. Among these modules, data collection and management module is a very important part of the system. In one hand, using the Visual C++ database access technology, the system can dynamically create a database and tables. In order to prove the correctness of the system, the data was divided into two parts: one is monitoring datasets, and the other is verified datasets. Each dataset has its own management operation interface. In the other hand, in order to find a corrosion protection status from the expert knowledge based on the monitoring datasets, this paper gives a study of the process of data mining, and an appropriate algorithm was established, then the algorithm was realized by programming.In order to test and prove the developed Visual OPCP system, the scaled model test in laboratory was carried out. The design process of the model test includes the optimization design of semi-submersible offshore platform and its cathodic protection system, the selection and disposal of reference electrode, and the selection of signal collection and transformation equipment. Through the model test, the practicality of Visual OPCP system was tested, and the reliability of real-time monitoring was proved. Furthermore, the correctness of evaluating the corrosion protection status at the early stage was proved.