Simulation And Evaluation Of Leakage Failure Consequences Of Gathering Line

The leakage failure consequences and safety distance of the gathering line under different working conditions are the basis for establishing the identification criteria for high-consequence areas of oilfield pipelines.In this thesis,the FERC pool spread model is used to calculate the radius of the pool area and the liquid fuel spill fire expansion area,and the solid flame model is used to evaluate the consequences of the pool fire and liquid fuel spill fire of the oil gathering line;methods for determining the safety distance of the oil gathering line based on consequences and risk are proposed,aiming at the liquid fuel spill fire and pool fire of the oil gathering line,the safety distances based on consequences and risk are determined respectively;the mathematical model method and the numerical simulation method are used to analyze the change rule of the axial dynamic pressure of the high-pressure water column after the high-pressure injection line leaked;the pressure drop model considering gravity is deduced,the variation of the safety distance of the high-pressure injection line with the injection angle is studied,and the safety distance of the high-pressure injection line is determined.The results show that the longer the leakage time,the later the ignition time,and the bigger the leakage hole,the more serious the consequences of oil gathering line failure;for big-hole leaks with a leakage time of 1 hour and an ignition time of 1 hour,the safety distance determined based on the consequences of the accident is 127.11m;based on risk,the safety distance of the liquid fuel spill fire accident is 64 m,and the safety distance of the pool fire accident is 121.75 m.If the leakage time is controlled within 10 minutes,the safety distance based on consequences will be reduced to 51.90 m,which is 59.2% lower than that when the leakage time is 1 hour.The damage distance of the high-pressure injection line is positively correlated with the internal pressure and leakage hole of the pipeline;when the leakage hole is0.05 m and only the influence of air resistance is considered,the safety distance calculated by the pressure drop model is 66.04m;the safety distance calculated by CFD simulation is 60.15 m,the calculation results of the two methods are consistent,and the error is less than 10%;when considering the influence of gravity,the greater the spray angle,the longer it takes to reach the highest point and the greater the maximum vertical displacement;the smaller the initial velocity component in the horizontal direction,the smaller the horizontal displacement,and the smaller the safety distance;the maximum safe distance when spraying horizontally is 66.04 m.The simulation and evaluation of the leakage failure consequences of the gathering line under different working conditions and the safety distance determined therefrom in this thesis can provide a reference for establishing the identification distance of high consequence areas suitable for oil field pipelines.