The Study On Leakage Law Of Entire Leakage Process For Long-Distance Crude Oil Pipeline

Currently,China's economy has been thriving with an unprecedented speed,which leads to an increasing consumption of crude oil and refined oil.With unparalleled superiority,pipeline has become the most important oil transport mode for now,and the scale of pipeline system has been rapidly expanding.However,some trunks undergo excessive long service time,in addition to design defects,corrosion,wear and tear,artificial destruction and other factors,which makes leakage accidents can happen occasionally.Considering that most carried matter in the oil pipeline is flammable,explosive and toxic,if not handled properly,it can easily cause fire,explosion,poisoning accident and other tremendous disaster leading to heavy casualties,significant economic losses and great social impact.Therefore,it is highly important to carry out a risk assessment to ensure the safety on oil pipeline transportation.Additionally,as a crucial issue in the field of oil pipeline safety,the calculation of leakage velocity and leakage volume is the precondition and basis to predict leakage consequences and evaluate leakage risk.In this paper,based on the existing research results taking liquid pipeline as an example,a leakage model is set up to study the effects of different factors on the leakage process in long-distance oil pipeline by changing the elevation and position of leakage point,the components of crude oil,the gas fraction of the oil in the pipeline and other parameters.The effects of control operations such as pump stopping,pressure keeping operation and etc.are taken into consideration to analyze the changing trend of leakage rate under different circumstances.According to the leakage control measures,the whole oil pipeline leakage process can be divided into two stages: before pump stopping period and after pump stopping period,which are both analyzed and the calculation methods are put forward respectively in this paper.Moreover,taking the "11.22" Sinopec Dongying-Huangdao oil pipeline leakage accident as an example,the leakage volume in the course of the whole process is calculated.A software to predict the leakage volume immediately in Dongying-Huangdao oil pipeline is developed as well,which is calculated on the basis of the calculation method of leakage rate in different stages with the leak position,diameter of leak hole,pipeline pressure drop and other parameters.According to the results,when a leak occurs,leakage velocity and leakage volume can be calculated immediately and accurately based on the leak location and other parameters combined with leakage control procedures,which can provide theories and data to support leakage risk evaluation and consequence prediction.