Patent ID: 7254091

Claim:
A method for estimating and/or reducing uncertainty in reservoir models of potential petroleum reservoirs, the method comprising the steps of: (a) receiving the results of a stochastic seismic inversion which provides output ensembles in respect of a plurality of properties on the basis of imaged seismic data obtained at points on an imaged seismic input grid over a region to be modelled, the output ensembles including information regarding the values of the plurality of properties at points on the input grid for a sequence of model layers, including means and covariances for the properties, (b) assembling information regarding an observed fault structure in the region, (c) assembling well log data in respect of one or more properties, obtained from well locations within the region, (d) modifying the geometry of the input grid to form an output grid for each layer, based on the observed fault structure and the seismic inversion results, (e) interpolating the values of the plurality of properties from the points on the input grid onto the output grid, (f) spatially smoothing the means and covariances of the output ensembles to produce a smooth trend map for each property and a smooth inter-property trend covariance, (g) performing a kriging adjustment of the property trends on the basis of the well log data so that the trends pass through the well log data, (h) simulating a set of spatially correlated random fields on the output grid for each property, and generating a set of realisations for each property on the basis of the random fields, the smooth inter-property trend covariance and the property trend maps, which honour inter-property and inter-layer correlations from the seismic inversion and measured well data, and (i) using the generated realisations in a reservoir model to conduct flow simulation and/or volumetric calculations in respect of the region.