Study On Deposition And Movement Laws Of Impurity And Effect On Corrosion In Product Oil Pipeline

The internal corrosion problem of product oil pipeline has great harm to the operation of the pipeline,the pipeline and the quality of the oil,thus resulting in huge economic losses.The deposited solid impurities in the product oil pipeline may capture water which lead to internal corrosion of the area in the product oil pipeline.Designed and built an experimental loop system of oil-dragging-impurities of horizontal-upturned-horizontal structure,which can be used to provide a reference guiding the security production of product oil pipeline,the mechanism of internal corrosion should be further studied and the flow behavior of water and impurity that entrained by oil.The deposition and movement of solid impurities in different tubes under different test conditions was studied by means of camera observation and ultrasonic top detection.The influence of solid contaminants on the deposition area and the influence of different influencing factors on the length of sedimentary area was determined.The critical flow velocity of solid impurity deposition was obtained under different experimental conditions.The results show that the main stable deposition area of sand particles is the upper horizontal section near the elbow in the pipeline of horizontal-upturned-horizontal structure;For a particular piping system and sand particles with a certain particle size,the length of the critical maximum deposition area of the upper horizontal segment particles is constant.That is,when the amount of the added particles is larger than the amount of the saturated particles,the impurity particles are not deposited in the region other than the critical maximum depositionarea,regardless of the amount of the particles added.And the law of deposition and movement of the water phase in the pipeline was studied.It was found that the water phase did not deposit in the horizontal section at high altitude,and the water phase could easily be carried out by the oil flow.However,when the impurity particles,The impurity particles will adsorb the flow of water,causing internal corrosion in the area of particles deposition.Therefore,a corrosion monitoring probe is provided in the particle deposition area in the height-horizontal section to monitor the corrosion rate after the water has flowed through this area.At the same time,the effects of the amount of adding water,water carrying rate,particle size and adding amount of the particle on the corrosion rate were studied.The critical flow rate of the removal particles is much greater than the critical flow rate of the removal of the water,so it is necessary to increase the oil flow rate to above the critical sedimentation rate to avoid the accumulation of water in the pipe.