Optimum Operation of a Gas Export System: Model Validation

The gas transport system on the Norwegian continental shelf (NCS) consists of 7800 km of pipelines and is the largest offshore network of its kind in the world. Natural gas is processed at treatment plants in Norway, and dry gas exported through pipelines to customers in the UK and continental Europe. These customers have the opportunity to make varying gas delivery nominations, and meeting such sales gas commitments is important. A major challenge is to operate the network at minimum cost, with minimum environmental emissions, fulfilling variations in contractual nominations and maintaining a sufficient pipeline inventory to provide operational flexibility. A model of optimum operation of a gas export system, including customer nominations, system integration, and operation of pipelines and compressor stations has been established in earlier studies. This model is based on analyses of actual operational data from the gas export system on the NCS. The scope of the work presented in this paper has been to validate this model so that it can be implemented in planning and operation of the gas export system. The purpose of the validation process is first to confirm that the model results are correct in that they represent actual system performance. Second, it aims to confirm that the model results satisfy all system requirements and the main objective of the work. The process includes developing and executing procedures, documenting validation results and considering possible modifications to the model.