Study On The Engineering Design Of Changqing-MengXi Gas Transmission Line

SuLiGe gas field loacate at E-Er-Duo-Si Basin of ChangQing oild field,reputed as one of the largest whole pack gas fields in the world, not only provides important gas resourses guarantee for successful practise of western gas-eartern transmission and construction of Shan-Jing second pipeline, but also assurance for the development of natural gas chemistry of peripheral area and other applications. In order to make full use of this resourse , with the lead of the strategy of great development of western region established and deployed by the country, E-Er-Duo-Si united chemical engineering group united company, which located at'Meng-Xi economic technique development area'-the first economic technique development area of Automomous region of Inner Mongolia, decided to launch the chemical fertilizer project with the government. Therefor it is of much necessity to instruct Changqing-MengXi gas transmission pipelines .Risk analysis of natural gas is made on the basis of market survey and prospect analysis. Main customers of the project are industrial gas usage and downline and peripheral urban of the cambustion gas. Analysis for the ability of replacement and sufferance for natural gas has been carried out, and the quanlity of gas transmission has been forecasted. According to the actual terrain condition of Changqing-MengXi pipeline project, two different routes are put forward, then an optimum route scheme is chosen by comarison. Partial plan optimization was carried out after dividing the optimum one into four segment. According to the standard, relative desing was made to the pipeline.In order to control outside corrision of piping system and prolong the life time of pipelines, Changqing-MengXi pipeline project uses outsides antisepsis layer combined with cathodic protection to protect pipelines form corrosion. Outside antisepsis of piping whole trunk line three layer PE structures, the wound repairment apploys hot constringency and the cathodic protection apploys compulsory electric currret. The cathodic protection station and the station field set up together. The mathematical models for the flowing of natural gas in pipeline were set up and solved. On the basis of the calculation the craft calculation is carried out for pipelines. Aiming at the downstream market can give three craft projects. One the Basis of craft comarision, calculation optimum plan is recommended by economic technique comparison. Analysis of function comporison is made for two kinds of steelpipes meeting the function in the market. On the basis of strength calculation, ths grade of tube type and steel category is confirmed, strength and stability check are carried out correspondingly. By the analysis of the downline natural gas custamers, the layout of the station field is confirmed, the station field craft is designed, and main equipments in the station is chosed out.The technique plan study carried out by the problems of great significance for directing the Changqing-MengXi pipeline project's design.