Can we reduce significantly the number of OBN by using Full Wavefield Migration?

This paper analyses the ability of Full Wavefield Migration (FWM) algorithms for providing an extended illumination for imaging without the OBN positioning constrain. Using deep-water OBN datasets, we investigate the effect of minimal sensor distributions on the resolution of the seismic image. Unusual OBN acquisition parametrization such as very limited aperture, extensive separation distance and innovative donut layout designs are investigated and discussed. The results demonstrate that the Full Wavefield Migration algorithm allows the reduction of OBN density, enabling a large distance between receivers and providing more geometry flexibility without compromising the image quality. An innovative OBN acquisition with a donut design is proposed for combining velocity modeling using refracted and diving waves (FWI) and imaging with Full Wavefield Migration. Reducing the number of nodes deployed for the same final image quality can positively influence the economics of an OBN acquisition survey.