The Study On Risk Analysis And Control Of Natural Gas Leakage In Offshore Production Platform

With the growing population,the oil&gas resources in the world are increasingly scarce,and the exploration and production of oil&gas have also been promoted from shore to offshore.Offshore platform as the infrastructure for drilling in offshore oil production,transportation,and construction activities,provides support on production and life for the exploration and production of oil&gas resources.In view of the suffering environment,intensive equipment and flammable and explosive characteristics of oil&gas in the offshore platform,the risk of deflagration accident of natural gas leakage in offshore production platform is high.It is necessary to carry out research on risk analysis and control of natural gas leakage in offshore production platform,which can improve the operation risk control ability and the level of risk management in offshore production platform.Considering the particularity of offshore production platform,the hazardous factors which include combustible substance,oxygen source,ignition source and natural gas leakage source are identified systematically.ISM method is introduced to construct the platform of marine production structure model of gas leakage,to determine the influence of surface direct reason,natural gas leakage in the middle and deep root cause indirect cause.ISM for influence factors of natural gas leakage of offshore production platform are established based on ISM method.The results show the surface direct cause,the middle indirect cause and the deep root cause of natural gas leakage.A comprehensive evaluation index system of natural gas leakage for offshore production platform is established.The weight of comprehensive index is solved based on AHP-entropy weight method,and the main factors affecting natural gas leakage are verified.According to the actual operating conditions,prediction and evaluation model of offshore production platform of natural gas leakage diffusion behavior is established based on CFD-based software FLACS.According to the key leakage source of risk identification,the influence range of leakage accident under different leakage position,flow rate and wind direction condition is compared and analyzed.Based on the leakage simulation results,the real gas cloud is ignited.Combined with the overpressure damage criterion,the effect of overpressure on deflagration accidents on people and buildings is evaluated.Based on Bayesian method,the Bayesian model of natural gas leakage risk evolution of offshore production platform is constructed,and the posterior probability of each base event is solved.The sensitivity of the system and the maximum possible path leading to the occurrence of leakage accident are studied.The linkage map of the natural gas leakage accident of offshore production platform and the risk linkage map of the emergency process of the explosive accident of offshore production platform are constructed.The graph theory,the shortest path,the key path and the point cut set are calculated respectively based on the graph theory.At last,based on the theory of chain accident,to prevent accident and control risk,develop offshore production platform of natural gas leakage accident safety barrier,deflagration accident of offshore production platform security barrier and marine emergency response platform production safety barrier,which can effectively improve the safety of the system.