Reservoir Characterization By Cokriging Petrophysical Well Data And Seismic Attributes

Describing the heterogeneity of a reservoir is a challenge to all geoscience disciplines. A full understanding of the depositional environment and the well performances can be used to generate a reservoir model that provides the most likely hydraulic response of the reservoir. Such a model may still be a poor predictor of inter-well reservoir properties, giving high uncertainty in development drilling and reservoir simulations. This uncertainty may be minimized if the seismic response is used to guide the interpolation of petrophysical properties and lithology changes between the wells. A brief introduction to geostatistics, including regression and correlograms, is provided. Two practical applications using this approach are then presented: Petrophysical properties from 17 wells and two seismic attribute maps are combined to generate cokriged porosity and productivity index maps of a producing field, explaining interference testing results. Electric logs and vertical seismic profile from a single well are used to produce sand volume cross section indicating location for an appraisal well.