Noise Behind the Signal – the limit on seismic data fidelity

The demands made on exploration seismic data increase as we move from simply providing an image of the sub-surface to reservoir characterisation and then onto reservoir monitoring. We are seeking to detect very small changes in the reservoir response caused by the impact of hydrocarbon production or stimulation when applying time-lapse seismic techniques. The conventional metrics that describe seismic data quality become largely inappropriate when trying to understand the data fidelity needed for reservoir monitoring applications. Noise behind the signal becomes the major delimiter of data quality. Noise behind the signal is introduced through the imperfections that we have in our seismic data acquisition and processing systems. They introduce a source generated, pseudo-random noise floor that limits the instantaneous dynamic range of our data. The presentation will introduce the causes of noise behind the signal and its impact on exploration geophysics. Opportunities for further research to minimise the effects of noise behind the signal will be discussed.