Patent attributes
A method of investigating a reservoir region in a subsurface formation by a time-lapse seismic survey. The subsurface formation comprises a further formation region adjacent to the reservoir region. Data are obtained from a time-lapse seismic survey and includes seismic data of the subsurface formation at a first point in time and a later point in time. The seismic data is processed to obtain a seismic representation of change in a predetermined seismic parameter in the further formation region, whereby the seismic parameter is dependent on stress. The seismic representation of change in the seismic parameter in the further formation region is interpreted for an indication of changes of stress distribution in the further formation region, and a property of the reservoir region is derived using the indication of change of stress distribution in the further formation region.