Reducing Reservoir Prediction Uncertainty Using Seismic History Matching

摘要

We have developed a method where the spatial and dynamic information offered by Time-Lapse (4D) seismic has been used in history matching of reservoir simulations. Improved predictions of both recovery and areal sweep are then obtained by reducing uncertainty. Flow simulations are converted to predictions of seismic impedance attributes using a petro-elastic transform and suitable re-scaling. The resulting misfit between the model and observed data is combined with an equivalent measure for well data and these are used to constrain simulations by iteratively updating the model. Updated model probabilities can then be used to analyse uncertainty. The method has been applied to a UKCS reservoir. Previously we described our success in obtaining a good match to both seismic and production data in the field. From the updated probability distribution of the parameters, we now take the best models from the history matching process and make predictions to determine the most likely outcomes. We have found that the Time-lapse data reduces uncertainty in predictions of the areal sweep and the pressure distribution. The seismic response is strongest at the injector wells but also helps in the inter-well regions. Conventional history matching often struggles to constrain parameters in these regions due to the inherent non-uniqueness of the problem. The uncertainty of permeability and fault transmissibility multipliers was also determined in those areas.