Research On The Low Throughput Crude Oil Pipeline Operation Based On The Reliability Method

Part of the oil field production decline year by year,following domestic oilfield exploitation degree,such as Daqing oil field.It makes some crude oil transmission pipeline into the operation of low throughput.For low throughput pipeline,it is the emphasis and difficulty in technology research to ensure safe and smooth operation,at the same time,realize energy saving and economic operation.For a long time,the traditional way of evaluating the safety of the pipeline operation status has always been the certainty evaluation method,but as a result of many factors affecting pipeline safety operation state are volatile,it will unable to quantitatively determine.That make the result too conservative,running energy consumption increases,or aggressive,influence the safety of pipeline operation.In this paper,combined with the actual operation condition of the Qin-Jing pipeline,based on the reliability method,the critical throughput of the crude oil pipeline determined,and the pipeline operation rule obtained.That will provide a valuable reference for the safe and economic operation to other low throughput pipeline.The crude oil physical property parameters and rheological parameters of Qin-Jing pipeline were obtained through crude oil physical properties test by means of rheometer.Probability distribution of some important parameters were determind,such as discharge temperature,heat transfer coefficient,throughput,ground temperature,etc,according to the historical operating data of Qin-Jing pipeline.Based on the hot oil pipeline steady state operating characteristics,the failure probability of dropping into the instability workspace were obtained for different throughput of Qin-Jing crude oil pipeline and then to determine the corresponding critical discharge temperature.At the same time,the failure probability of dropping into the instability workspace were obtained for different discharge temperature,different ground temperature,different heat transfer coefficient,and then to determine the corresponding critical throughput.In this paper,the actual operating conditions of different seasons for Qin-Jing crude oil pipeline were evaluated,the degree of safe operation were quantified,and some economic operation suggestions were put forward on the premise of ensure safe operation.