Paper Summary

A receiver decimation study has been performed for assessing the potential of using very sparse receiver grids in conjunction with high-order multiple imaging techniques for 4D reservoir monitoring. Reducing the density of receivers in a PRM (permanent reservoir monitoring) system will reduce the capital expenditure. For OBN (ocean bottom node) acquisition, cost saving can be achieve from more effective node deployment. The imaging process makes use of the multiple sea-surface reflections to significantly increase the fold, hence compensating for the reduced number of sensors. We will show that with the above imaging technology it is possible to use sparser seabed recording geometry without compromising the 3D or 4D image quality. Using the Jubarte PRM dataset acquired by Petrobras, the decimation test consists of taking out receiver included into circular patches within a diameter of 600 m. The number of sensors is then reduced by a factor two. The results demonstrate that it is possible to break some established limit in term of seabed sensor sparseness without compromising the resolution of 3D/4D imaging.