Patent ID: 7840394

Claim:
A computer implemented method for generating a 3D earth model for determining at least one characteristic of an area formed by a plurality of formations and comprising drilling positions of real or planned wells, the method comprising the steps of: constructing, using a computer, an initial 3D earth model on the basis of measurement data and known properties of the area by combining solutions for a set of single 1D earth models with solutions for a set of 2D earth models, each of the 1D earth models corresponding to a drilling position of a real or a planned well and covering a number of formations along a bore of the respective well, and each of the 2D earth models covering a formation covered by at least one of the 1D earth models; and optimizing, using the computer, the constructed initial 3D earth model by: (i) determining an optimal set of formations for each 1D earth model by analyzing an effect of each of the formations along the bore on the characteristic being determined and removing formations weakly affecting the characteristic being determined by merging those formations with host formations, and (ii) determining an optimal set of adjustable model parameters by analyzing an effect of 1D earth model parameters on the characteristic being determined and removing those parameters whose variations weakly affect the characteristic being determined.