Study On Temperature And Pressure Change Of Product Oil Pipeline Shutdown And Software Development

Long-distance oil pipelines are generally considered to be designed and operated as isothermal oil pipelines.Owing to the neglect of the heat exchange between the oil products in the pipeline and the surrounding media,some thorny problems are often found in the actual operation of the pipeline.Among these problems,the continuous decline of the pressure inside the pipe after the pipeline shutdown is the most critical and common one.It is related to whether there is gasification in the pipe during the shutdown process or whether it can be safely and smoothly restarted.Therefore,research and application of temperature and pressure changes in the pipe after the oil pipeline shutdown is of great significance to ensure the safe operation of the pipeline and improve the operation efficiency.This paper takes the southwest oil product pipeline as the research object and uses its SCADA production data as the research data source.Firstly,based on the inverse problem analysis theory,a parameter identification model is established for the parameters that cannot be directly obtained in the study,and a large number of known data are used to identify the unknown parameters.Then based on the physical properties and heat transfer theory of the product oil with expansibility and compressibility,the mechanism of its production is explained,and the different kinds of pressure drop phenomena appearing are analyzed.Secondly,based on the pipeline basic data and theoretical calculation method,the calculation model of the temperature-pressure change of the southwest product oil pipeline is established.Compared with the actual stop data at the site,the model calculation error is controlled within 5%,which can effectively calculate the pressure change inside the pipe after shutdown.Finally,based on the stop temperature-pressure change model and using the open source program framework Grails,the software of temperature and pressure calculation and application for shutdown of refined oil pipeline is developed.The temperature and pressure calculations have been realized,and the functions of stop-and-hold pressure-preserving schemes,calculation of stop-capacity change,and oil stealing and leakage monitoring have been expanded.The software is currently installed to the on-site control center,it has the practical application value of the project and can provide certain reference and technical support for the onsite dispatchers.