GLOBAL OPTIMIZATION OF THE ALGERIAN GAS PIPELINE NETWORK GLOBAL OPTIMIZATION OF THE ALGERIAN GAS PIPELINE NETWORK Abdelkrim Ainouche, Manager of the gas department SONATRACH / RTE, B.P. 49 Skikda 21000 Algeria; Abdelnacer Smati, INH University Boumerdes 35000 Algeria. Abstract. Algerian gas network is a complex system. Because of the competitive nature of international markets and the growth of local demand, it takes place to solve the problem of the optimisation of the global system by the maximal reliability criterion. An approach based on an original representation by the theory of graphs and the use of the maximal flow with minimal costs algorithm is developed. Results to Algerian gas network will be given.
1. MODELISATION OF THE LNG CHAIN BY THE GRAPH THEORY The natural gas is revealed to have number of trumps that confers him a major place in all The procedure of modelling is realized scripts of forecasting energical demand. Thus under two steps: during the last twenty years the natural gas has recorded the strongest rate of growth among the · Defining a graph representation fossil energies. Its part of market has passed conformable to the objectives, progressively from 18.9% in 1975 to 23% in · Defining matrixes associated with the graph 1997 to reach 25% in 2010 corresponding to a representation. demand of about 3700 billion of m3. Algeria is In its classical configuration, an LNG chain is one of the biggest worldwide exporter of natural composed by: gas and LNG. In addition of its proximity to the · A source, representing the gathering European markets and its important reserves, network and the gas treatment plants, Algeria disposes of a complex network of · pipelines destined to assure the covering of the A pipeline equipped of many compressor national needs and exportations. The stations, international gas market, especially the European · A liquefaction plant disposing of many one, is strongly competitive. Consequently, the modules, reliability appears to be an essential criterion for · Cryogenical tanks of LNG, the conservation of market parts and the · A carriage with many posts, acquisition of new clients. Beyond current · A methanian fleet, actions of preventive maintenance, the · A delivery to the clients who are situated at amelioration of the network reliability, in the the pipeline extent. sense of market supply security, passes by: A graph representation of this configuration · The rehabilitation of corroded pipelegs, is very easy. To complete the graph modelling · The interconnection of the existing we add fictious arcs representing the gas pipelines, consumption at compressor stations and LNG · The realization of underground storages, plants. The modelling of a complex network · The increase of storage capacities of the disposing of many LNG chains is based on LNG plants. elementary graph defined more upper. In order to transform the resulting graph on a transport These actions have a very high cost. network