The Research Of Evaluation And Prediction On Effect Of Drag Reducing Agent

An growing of the oil pipeline network scale and oil demand,the proportion of pipeline transportation in gathering and transportation system increases day by day.Facing the question that how to realize drag reduction and increase transportation capacity of pipeline,It is particularly significant to improve economic performance and effectively control the delivery flexibility at the same time.In recent years,Drag Reduction Agent(DRA)has been large scale use in drag Oil industry.All of pipeline transport company can only use method of ‘trying' to optimize the drag reduction agent and ensure additive dosage because of the seriously lack of standard and the system of effect prediction for this new polymer which can reduce drag and increase transportation capacity and adjust the pipeline transport flexibility.This has brought great restrictions in popularization and application in phases of optimization during the design and promoting the application during operation,also,energy saving and consumption reducing in oil transportation.For the shortcomings and problems exists in application and effect prediction of DRA,this subject mainly aim to establish and optimize the performance evaluation model of the agent,put forward the evaluation index of the agent and develop the online evaluation software for drag reduction effect.Therefore,the whole operations management can become more reasonable and economical from optimization in design stage to increasing capacity in operation stage of oil pipeline.Firstly,since the current mechanism of drag reduction is still unclear,by analyzing various hypotheses on drag reduction mechanism,start with the DRA and turbulence structure,nature of drag reduction polymer molecular and its motion feature in the turbulence,analyze the mechanism and the action process and principle of DRA,and proved by the indoor loop test data and previous microscopic research achievements,a hypothesis of inhibiting turbulence additional stress in transition layer is posed in this paper.This hypothesis makes up the insufficient of the early hypotheses,and is reasonable to explain the variety phenomenon during DRA function process.Secondly,according to the absence of drag reduction effect prediction formula currently,by analyzing the results of previous research and influence factors,this paper starts from the reference flow increase rate,the friction coefficient variation and the data fitting,3 directions to establish 3 anti-drag effectiveness evaluation models,and gives calculation method of the models.The accuracy of this forecast evaluation system has been proved by the model validation with the DRA field-test data of West Pipeline Company.Finally,according to previous research results and the insufficient in the DRA manufacturer description,the DRA performance evaluation index is proposed,to guide manufacturers to handle the test data before delivery and calculate the corresponding DRA performance evaluation index,thus provides reference and avoids blind test for clients.Simultaneously,the online drag reduction effect evaluation software is programed to real time read the drag reduction rate and the throughput increasing rate.