4D Simulation-to-seismic Modelling as a History Match Constraint for a Gas Development Project at Harding and Gryphon

4D (time-lapse) simulation-to-seismic modelling has been used to update and validate geological and simulation models to help assess the range of possible in-place gas volumes and the degree of inter-field connectivity for a large future gas development project in the Harding and Gryphon fields of Quad 9 in the Central North Sea, UKCS. The traditional workflow of reservoir simulation and production data history matching has been extended to include 4D seismic data that were recorded through the life of the fields. Synthetic 4D data were generated from the regional geological and simulation models and compared to the real 4D data. Discrepancies were used to infer modifications to the models particularly for the quantity and distribution of reservoir sands and inter-field connectivity. Consequently, 4D seismic data has provided an additional, independent and aerially extensive history match constraint leading to improved geological and simulation models. This has increased confidence in the range of recoverable gas volumes and helped to provide a better basis for further development planning.