StatoilHydro and Gassco: Optimizing the Offshore Pipeline System for Natural Gas in the North Sea
The Problem
The transport network of natural gas on the Norwegian continental shelf is the world’s largest, built with 7800 km of pipelines. Systems effects are prevalent in such a large, complex network, and so the network must be analyzed as a whole to determine optimal operation (systems effects appear in complex systems but not in the simple components of these systems).
The Analytics Solution
To examine this vast network, researchers from SINTEF worked in close cooperation with representatives from StatoilHydro and Gassco (the main Norwegian shipper of natural gas and the independent system operator, respectively) and developed an analytical tool.
Their first efforts included a flow maximization model with physical details of natural gas flow, focusing on maximization of throughput and contract fulfillment.
Several of the technical details and characteristics needed to model natural gas flows created modeling challenges. Deliveries have to meet contractual specifications for energy content, pressure, and levels of contaminants. Several aspects of the gas routing problem are described by nonlinear relationships, and these have been linearized and discretized in the StatoilHydro/Gassco/SINTEF model GassOpt.
The Value
GassOpt allows users to graphically model their network and easily run optimizations to find the best solutions quickly. This tool is used to evaluate the current network as well as possible network extensions. Analytical methods are now an integrated part of the work of the
departments responsible for transport planning, security of supply, and tactical analyses such as energy studies, and are used strategically to verify details of planned infrastructure developments.
The analytics tool is used to model the operation of a system with a capacity of 120 billion standard cubic meters of natural gas a year. StatoilHydro estimates the accumulated savings related to their use of GassOpt to be a whopping NOK 10 billion ($1.8 billion).
