Network modeling and analysis west zone gas transmission pipeline network of Bangladesh

Abstract

The natural gas transmission pipeline network in the Western Zone of Bangladesh currently comprises of 246 kilometer of pipeline. About 110-120 MMscfd of natural gas, which is 5% of the total production (2350 MMscfd), is supplied through this network. The Government has planned to supply gas to more areas in the north and south western regions of the country. About 177 kilometer of pipeline is already constructed for this purpose, which will be connected to the existing network in near future. Thus natural gas will be available to Kushtia, Jhenidah, Jessore and Khulna districts. Compressor stations are also being erected at Elenga, Tangail and Ashuganj, Brahmanbaria to boost up the pressure and throughput of gas through this network. Detail study is needed on the west zone gas transmission network regarding pressure drop along the pipeline and availability of gas at various off-takes. Prediction of pressure drop along the pipeline in a network is very important as it indicates the pipeline efficiency, volumes available at various off-takes/outlets, maximum possible distance of transmission for a given upstream pressure, effect of compressors, etc. This kind of study requires numerical simulation with powerful computational resources. This study presents some results from the simulation study of the west zone gas transmission network. A virtual model is constructed, which includes both the existing and new extensions to the network. The model is first validated by matching with the existing network using known data. Then simulation runs are performed to investigate the issues mentioned above. In addition, sensitivity studies are performed to investigate the effects of supply-demand fluctuations. Commercial software package PIPESIMTM is used for this work. The starting node of the network is at Elenga, Tangail. The existing pressure at this point is 400 psig. The fare most downstream point of the network is Khulna. The study will improve operational standard consistent with the world gas industry which will be helpful for smooth operation of the network. The study will also be helpful for proper planning and design for augmentation of national gas grid for the uninterrupted transportation of natural gas in safe, reliable and economical way to the demand centers for ultimate distribution of the same.