Hull Structure Assessment During FPSO Tank Washing Based On FSA

With the world's increasing demand for oil, ocean petroleum resources development has attracted increasing attention. As the main tool for offshore petroleum exploitation, the safety of Floating Production Storage and Offloading (FPSO) is becoming more and more attention. Especially, marine perils make people realize that is important to carry out Security Assessment of FPSO.Security Assessment is refers to the use of specific information, using a series of logical step, accurate identification of hidden danger or weak links in equipment system security, evaluation of partial or whole safety, and put forward the improvement or preventive measures. As the security assessment method recommended by IMO, Formal Safety Assessment (FSA) is a systematic and structured analysis method, which can fully consider the various factors affecting the safety. FSA can put forward the reasonable and effective control scheme. It's a huge project to carry out formal safety assessment for FPSO. Therefore, this paper only carries out comprehensive hull structure security assessment of FPSO crude oil tank washing, with "Nan Hai Fen Jin" for example.Firstly, this paper analyses the reasons of tank on-line washing, and introduces the steps and cargo and ballast progress of washing by examples.Secondly, this paper studies the FSA, and introduces the application and development situation and process and procedure.And then, this paper studies the establishment and analysis of evaluation system, and focus on the multi-level fuzzy comprehensive evaluation method.Finally, according to the step of FSA, using the fuzzy synthetic evaluation method, this paper identifies the risks for "Nan Hai Fen Jin" FPSO. This paper concludes the weight of each index, and puts forward the corresponding measures, based on calculation and analysis of expert questionnaire. This paper assesses the security of important events in the cargo and ballast progress, and puts forward the corresponding measures. This paper puts four risk management schemes, according to results of the hazard identification and risk assessment, evaluates the scheme on the cost and efficiency, and puts forward decision-making scheme eventually.The achievement in this paper can provide theory basis and technical conditions for improvement of FPSO hull structure security, and lays foundation for further research of FPSO security.