Study On Quantitative Risk Evaluation Of In-service Subsea Pipeline

Subsea pipeline is the lifeline of offshore oil and have stepped into a rapiddevelopment area in China. With its development, the safety problem of subseapipeline has gradually emerged. It’s crucial that the ability of predicating accidentsshould be improved so as to realize effectively transportation. The purpose of studyon quantitative risk evaluation of subsea pipeline is to improve the reliability in theprocess of oil&gas transportation, to improve the capability for accidentspredication, to reduce the economic loss, injuries and environmental destroy causedby subsea pipeline accidents as little as possible. Therefore, it is of great significanceof studying the quantitative risk evaluation of subsea pipeline.According to the characteristics of in-service subsea pipeline and researchstatus of pipeline risk management, this paper developed the calculating model ofrisk evaluation suitable for subsea pipeline. The following contents are mainlyconsidered：（1）According to systematic studies on characteristics of subsea pipelinefailure, the main risk factors and weights of subsea pipeline were defined.（2）A systematic analysis on the statistical data at home and abroad, whichreveals the statistical law of subsea pipeline failure. In the meantime, the dometicfailure frequency was given.（3）An analysis on general models of pipeline risk assessment and pipelinerisk acceptable criteria. According to ALARP, utility function was used to define thelimit of subsea pipeline acceptable risk.（4）The calculating model of subsea pipeline failure frequency was developed,which calculate failure frequency caused by corrosion, third-party interference,manufacturing defect, natural hazard and structure&strength.（5） A multi-dimension calculating model of subsea pipeline failureconsequences was developed to assess the consequences of injures, environmentaldestroy, production loss, maintenance cost, effects of reputation, cleaning cost andtotal consequences caused by subsea pipeline failure. （6）The quantitative calculating model based on barrier theory suitable forsubsea pipeline risk evaluation was developed and was applied to a typical pipeline.The main innovative points in this paper are as following:1.According to the systematic studies on characteristics of subsea pipelinefailure, the risk factors of subsea pipeline were given.2.The calculating model of subsea pipeline failure frequency and consequencieswas developed.3. The quantitative risk evaluation model was given based on barrier theory.