Study On Safety Operation Technology Of Natural Gas Pipeline Network In North

With the development of economic and industrial construction, and influenced by the weather effects, the consumption of natural gas in Northern XinJiang has increased year by year. This brings two problems, the first one is the change range of pressure and quality when Feng Cheng’s gas usage is increasing, and the other one is the change range of pressure and quality when the usage of thickened oil users is changing dramaticly in winter. To solve these problems, it has become the first issues to predict the usage of gas load, and to analysis the delivery capacity. As a result, gas load prediction, dynamic simulation, and technologic optimization need to be analysised thoroughlys. The main contents are as followed.1、Gas load is one of the most necessary factors that we need to fully understand it. It is important for efficiently function, optimal operation and scientific administration. Based on a large scale of investigations about Northen Xinjiang natural gas system, and combined with the present research state of the gas load, this paper makes a deep research on the city’s gas load forecast system with a wealth of advance intelligent methods. The main contents are as followed:(1) Based on1460days of gas load datas (from2008to2011), the matching curves show that if the historical data has only one turning point, Grey System method has the best goodness of fit, with the relative errors less than5%. If the historical data has more than one turning point. Grey System method’s relative errors may be more than5%, while the combined forecasting method shows the best goodness of fit. with all the relative errors less than5%. Regression Analysis method is dull for turning point.(2) Three methods all fit for focasasting the annual gas loads, with the relative errors less than5%in forcasting the gas load of2012. Grey System method shows the best fitness, the combined method takes the second place, and Regression Analysis method is the worst one. While when each month’gas load is predicted, the combined method takes the first place.(3) Gas load of2014is predicted. Gas load in2014will reach57.121×104m3/a according to Grey System. Gas load in Dec.2014will reach5.0592×104m3/month, which is predicted according to the combined forecasting method.2、To match the demand of production department, Pipeline studio is introduced to build Northen Xinjiang natural gas system model, with a comprehensive consideration of friction resistance coefficient, transport efficiency, equation of state, gas compose and so on. Accuracy of the model has been checked to make the relative error is less than3%. This model is used to simulate the gas system, and the main contents are as followed:(1) The demand of natural gas in Feng Cheng is constantly rising, with the development of thickened oil recovery technology and the enhancement of oil field production.10different operation schemes have been proved when the peaking gas sources are changing.(2) Because the thickened oil deliveries occupy almost40%of the whole delivers, dividing thickened oil deliveries into3parts and considering the changing of different thickened oil deliveries parts have a different influence on gas system. When the sum of consumption is changing, more than hundreds of conditions are simulated and50different operation schesmes have been proved.(3) Aspen HYSYS is used to calculate narural gas water content.In that way, a comprehensive evaluating system of natural gas safe operation has been built, and the simulatinsg results can be evaluate.3^To match the demand of production department, a comprehensive evaluating system of natural gas safe operation is built. Factors that influent natural gas system safe operation, including pipeline flow, pipeline pressure fluctuation, aqup-complex harm, and pipeline gas storage are selected as the important factors to support evaluating system.(1) An evaluating system of Feng Cheng has been built after a comprehensive consideration of pipeline flow, pipeline pressure drop, aqup-complex harm, and pipeline gas storage. The result shows that the best scheme is similar with the most safty one. while they are not the same. The best one is that Wang Jia Gou station supplys200×104m3/d of natural gas, and Wu Shi Hua station supplys243×104m3/d of natural gas.(2) An evaluating system about thickened oil deliveries fluctuature has been built after a comprehensive consideration of pipeline pressure index, aqup-complex harm, and pipeline gas storage. When the thickened oil deliveries fluctuate, different operation schemes have different influence on gas system. Based on safe operation, different schemes are evaluated by the evaluating system. The best operation scheme is neither taking scheme quickly nor taking scheme slowly, while it relates to the time of scheduling control.