Analysing fracture networks by comparing different seismic time lapse vintages

A method of analysing the dynamic behaviour of fracture networks in a seismic volume comprises providing 10 a plurality of seismic time lapse (4D) vintages of the same geological volume, identifying 40 and parameterising 50 fractures within fracture networks of each vintage, determining 60 one or more distributions of fracture parameters for the fracture networks of each vintage and identifying 70 changes to the fracture networks by comparing corresponding distributions of fracture parameters across the vintages. The method may be performed on a number of sub-volumes of the geological volume. The vintages may be compensated for changes in seismic velocity between the vintages. The parameterization may include determining strike azimuths, inclinations with respect to horizontal or the areas of each fracture. The analysis of the fracture networks may be useful in managing the drilling or operation of a well.