Summary
Down-hole seismic monitoring in the form of time-lapse 3D VSP has emerged as a technically viable alternative in areas where reservoir monitoring via conventional 4D seismic recorded on surface is not expected to be technically successful due to low SNR or insufficient repeatability. But even after the technical case is proven for time-lapse 3D VSP – often a major and protracted task – a larger hurdle remains to make the technique affordable on a field-wide scale. We discuss how the emerging technology of Distributed Acoustic Sensing (DAS) may be used to clear this hurdle both onshore and offshore.