Institut Francais Du Pe'trole

Laboratoires Hoechst S/a

Vincent Richard

Helmut Bohn

Piero A Martorana

Michel Leger

Thierry Tonellot

Jacques Dreux

Michel Cuer

Jean-Pierre Nallet

Pierre-Yves Dequirez

Alain Berdeaux

Fr&eacute;d&eacute;ric Dumont

Dani&eacute;le Mace-Prieur

Laurent Grizon

A method of obtaining a representative 2D or 3D model of a heterogeneous medium described by multiple physical parameters (such as the impedances of the subsoil in relation to P or S type waves, its density, etc.) from various data. An a priori model with multiple parameters formed from known or estimated isolated values of the physical parameters and the initial model is improved by minimizing a global cost function representative, on the one hand, of the differences between synthetic records giving the response of the current model and the seismic records obtained, and on the other hand of the differences between the current model and the a priori model. These differences are measured in the sense of norms deduced from the a priori information on the uncertainties relative to the data and to the model, and the information can vary from one point of the model to another. The invention has an application for characterization of hydrocarbon reservoirs.

Method for 2D or 3D modelling of a heterogeneous medium such as the subsoil described by one or more physical parameters

A method for 3D modeling of the impedance of a heterogeneous medium from recorded data corresponding to waves coming from the heterogeneous medium (such as a subsoil zone), in response to (for example elastic or electromagnetic) waves transmitted therein, and from an a priori 3D model of this heterogeneous medium, knowing the position of various impedance discontinuities of the medium, and after stratigraphic interpretation is disclose. The method comprises constructing a 3D geometric model comprising several foliated volumes (such as sedimentary units foliated by the deposition isochrones) with definition of the different sheets, constructing an a priori impedance model from this geometric model and from a plurality of impedance measurements taken at various depths of the heterogeneous medium (in a well for example), selecting a covariance model (exponential for example) along the sheets of the foliated volumes, and forming the optimum model by recorded data inversion using the a priori impedance model. The method can be used notably for studying the configuration of hydrocarbon reservoirs for example.

Method for 3D modelling of the impedance of a heterogeneous medium

Organic nitrates, processes for their preparation and their use in the

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Paris, France

Vincent Richard