2D Nonlinear Basement Modeling for Hydrocarbon Exploration by Gravity Data, Carlisle England Area

Sedimentary basins have always been considered as one of the prerequisites for the presence of hydrocarbon resources, and the study of the geometry of these basins has always been of great importance. In this paper, subspace method has been used for non linear inversion of gravity data for the basement modelling. That is the high stability in contrast the noise and efficiency of the method for inverse modelling of geophysical data. The subspace method is based on successive iterations, and at each iteration, a perturbation of model parameters in a p-dimensional subspace of an m-dimensional model space is sought. The primary model is updated using the perturbation values of the model parameter.
So, inversion in successive iterations used the one step of obtained result in previous step which is the same as primary model. Basis vectors of P-dimensional subspace are extracted by the SVD of a second derivation of model parameters. M-dimensional model space is projected onto P-dimensional subspace using basis vectors.
The practical effectiveness of this method is demonstrated by inversion of synthetic and real examples. The real gravity data is acquired over the Carlisle England Area. The results have been compared with those of geological section at the study area.