A process for characterising the evolution of an oil or gas reservoir over time

摘要

A method for characterising the evolution of a reservoir by determining a seismic wavelet which links observed seismic data to a sequence of reflectivities comprises obtaining 200 seismic data representing seismic changes which have occurred between a first time and a second time (i.e. time-lapse changes), said seismic data comprising a plurality of seismic traces; and performing 230 an optimisation operation simultaneously on the seismic traces so as to optimise for said seismic wavelet. The optimisation operation may be performed without using known reflectivity data as an input. The optimisation may comprise minimising a cost function comprising a measurement of the difference between the seismic data and a convolution of the seismic wavelet and the reflectivity change data.