Study On Risk Evaluation Technology Of Oil - Bearing Station In Finished Oil

Oil and gas transmission stations are key units in long distance pipeline systems, undertaking significant functions such as pressurizing, receiving, distributing, pigging and metering. Security circumstances of facilities in stations are severely concerned by country and society. Compared with long distance pipelines, facility types, technological process and technical requirements in oil and gas transmission station are quite different. Risk assessment techniques of stations are in exploratory stage.In order to improve the risk assessment techniques of oil and gas transmission stations, the risk assessment techniques of product oil intermediate stations are researched in the paper. The primary research contents are as follows.Failure modes and reasons of typical station facilities are analyzed based on failure mode and effects analysis (FMEA) method, which obtains main risk factors. Considering the lack of domestic facilities failure database, a method of failure rate calculation based on expert opinion is proposed.In the view of risk, product oil intermediate transmission stations are divided into several subsystems, such as pig receiving subsystem, decompression subsystem, filtration subsystem, contaminated oil disposing subsystem, pressurizing subsystem, metering distributing subsystem and pig sending subsystem. Based on GO (goal oriented) methodology, failure probability analysis method is established with taking malfunction correlation, maintaining correlation and redundancy correlation into consideration.Failure consequence models of oil transmission station facilities are ascertained by event tree analysis (ETA). Quantitative calculation models of probability and hazard area of pool fire, vapour cloud explosion and flash fire are established respectively. Assessment methods of casualties and financial loss are given.Fuzzy inference system is applied to calculate risk in order to avoid insufficients of risk matrix method and risk value calculation method based on loss expectation. It can not only obtain risk levels, but also ascertain ranking in the same risk level. On the basis of previous research, a risk assessment model of product oil transmission stations is established and the assessment process is introduced briefly.One station of Lanzhou-Chengdu-Chongqing product oil pipeline is assessed by the risk assessment model established in the paper. Results show that risk level of station is acceptable which mainly accord with operation circumstances.Research achievements obtained in the paper can supplement and improve existing oil and gas transmission station risk assessment techniques and integrity techniques, which can provide theoretical support for safe operations of oil pipeline systems.