Abstract
The network for transport of natural gas on the Norwegian Continental Shelf, with 7,800 km of subsea pipelines, is the world's largest offshore pipeline network. The gas flowing through this network represents approximately 15 percent of European consumption, and the system has a capacity of 120 billion standard cubic meters (bcm) a year. In a network of interconnected pipelines, system effects are prevalent, and the network must be analyzed as a whole to determine the optimal operation. SINTEF has developed a decision support tool, GassOpt, which is based on a mixed-integer program, to optimize the network configuration and routing for the main Norwegian shipper of natural gas, StatoilHydro, and the independent network operator, Gassco. GassOpt allows users to graphically model their network and run optimizations to find the best solutions quickly. StatoilHydro and Gassco use it to evaluate the current network and possible network extensions. Both companies use operations research (OR) methods in the departments that are responsible for transport planning and security of supply. Several new OR projects have grown out from this cooperation. StatoilHydro estimates that its accumulated savings related to the use of GassOpt were approximately US$2 billion in the period 1995–2008.