Assessing the value of time-lapse seismic in history matching and forecasts of the Schiehallion field

History matching is performed by reducing the difference between observed dynamic data and predictions based on reservoir simulations. Time-lapse (4D) seismic offers spatial information in the inter-well region and acts as additional constraints to more conventional production data from wells. As such, models that match production data may fail to match seismic and should be rejected possibly leading to alternative parameter choices for modifications to models. In this study we compare the effects that 4D seismic data has on the history matching process in the Schiehallion field. We investigate the alternative outcomes that may be obtained by forecasting an infill well for which we have history data. We find that a number of models suitably constrained to production history data alone offer equivalent forecasts to each other while the use of seismic, along with production data or on its own, offers a greater range of forecasts. The best models are obtained by making use of time-lapse seismic.