A 009 HISTORY MATCHING WITH THE PROBABILITY PERTURBATION METHOD – APPLICATION TO A NORTH SEA RESERVOIR

This paper presents a general history matching technique to create simulation models that honor prior geological information and match production data. The methodology relies on a region-wise perturbation of the probability distributions used to generate the reservoir models. Perturbing probabilities rather than actual petrophysical properties guarantees that the conceptual geologic model is maintained and that border artifacts are avoided. By allowing the properties in different region to be perturbed by different amounts, an efficient match of the observed data can be found. A simple and efficient optimization method is used that can jointly optimize the magnitude of the perturbations and is able to handle a large number of regions. Additionally, the method allows large scale reservoir properties such as the location and regional proportion of facies bodies to be perturbed. The important issue of how to define region geometries is also discussed.