Ekofisk Field redevelopment: improved reservoir management through cross-discipline technology and integration of three dimensional models

Abstract

The Ekofisk Field is currently undergoing a major field re-development in which 45 new wells will be drilled before the end of 1998. This requires that the most comprehensive and detailed reservoir description and geological and fluid flow models be used as the basis for the planning of such a redevelopment. This situation, as well as new developments in hardware and software and multidisciplinary database and applications integration, led to the decision in 1994 to completely re-evaluate the reservoir characterization of the field. A major multi-disciplinary effort involving geoscience, petrophysical and reservoir engineering work was initiated through the Ekofisk reservoir characterization (ERC) project. The objective of the reservoir characterization project was to improve the existing reservoir description using all available data through the application of new techniques and technology, and to construct and history match a new 3D reservoir fluid flow model using this updated, detailed reservoir description. Greater demands are being made on geoscientists and engineers to model and manage processes taking place within the reservoir. At the same time systems are evolving which allow large and complex models to be developed and modeled in simulators. The development of these models, and asset management based on these models, are becoming requirements for effective reservoir management. Our biggest challenge is to maintain, update and interchange data between the large 3D reservoir description models and fluid flow models through integration of new data. Up-scaling of the detailed description produced the highest resolution model that is computationally manageable. The resulting history-matched fluid flow model provides the primary reservoir management tool for the field re-development programme and for the evaluation of reservoir and geoscience monitoring technologies. Down-scaled reservoir parameters are currently being integrated with petrophysical data and laboratory core analysis to drive seismic forward modelling of present and future reservoir conditions. These seismic simulations are being used to evaluate the implementation of a time-lapse seismic (4D) monitoring programme for the field.