A New Method for Updating and Assessing Validity of Prior Reservoir Models

The paper presents a new approach for updating reservoir models beeing history matched previously. The main concern regarding any reservoir model is to maintain the predictive capability. Practical experience shows that this capability is lost very soon. Consequently updating of prior simulation models goes along with significant changes in the model itself. Often this requires not only tuning of the aquifers but also modifications of the reservoir properties. Based on the results it will be decided if the model is still valid or if an entire update is necessary. A newly developed method called Target Pressure and Phase Method (TPPM) provides a mean to significantly improve this process. TPPM does not only speed-up this update procedure but additionally assesses the validity of the model reliably. In the conventional history matching workflow pressures, water-cut and GOR are calculated and the reservoir model will be changed until it fits the history. TPPM considers the pressure measurements and the oil/gas/water production rates as input and determines the aquifer parameters and the well conditions needed in order to match the given historical measurements. The paper will present the basic idea as well as its applicability to a field case.