摘要 |
According to the invention, elastic parameters, including density, pressure wave propagation speed, and/or shear in pervious layers located in a dense underground area along an array of horizontal positions, are estimated by inverting 4D seismic data. Firstly, an estimate of variations in the elastic parameters in one or more starting positions of the array, which can be located on bored wells within the area in question, is obtained. Then, a propagation algorithm is used in order to gradually carry out the 4D data inversion on the basis of the starting positions. The inversion takes into account the previously estimated parameter variations. A spatial variation in the depth and/or the thickness of the pervious lavers in question can also be taken into account. Propagation is based on positions that are consecutively selected as providing optimal values for a cost function assessed in order to invert the 4D data.
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