Abstract: A method of monitoring a CO2 geological storage site by locating the CO2 plume from 4D seismic data is disclosed. A stratigraphic inversion of the seismic data is performed in order to obtain the P and S impedances, before and after CO2 injection. A density variation cube and an incompressibility modulus variation cube are constructed from the seismic impedances. The free CO2 plume is located within the subsoil by identifying, within the cubes cells where the density variation is negative and where the incompressibility modulus variation is negative, which are of an absolute value greater than a given positive threshold.

Abstract: A method of locating argillaceous zones present in a geological layer from seismic data where a gas has been injected is disclosed. From a discretization of the layer into a set of cells, a first set of cells containing CO2 is identified by seismic data analysis of a first criterion. A second set of cells containing shale is identified by a seismic data analysis by a second criterion. The number of cells identified containing both shale and CO2 is then determined from the set of cells which are identified.

Abstract: A method of monitoring a CO2 geological storage site by locating the CO2 plume from 4D seismic data is disclosed. A stratigraphic inversion of the seismic data is performed in order to obtain the P and S impedances, before and after CO2 injection. A density variation cube and an incompressibility modulus variation cube are constructed from the seismic impedances. The free CO2 plume is located within the subsoil by identifying, within the cubes cells where the density variation is negative and where the incompressibility modulus variation is negative, which are of an absolute value greater than a given positive threshold.