Successful Imaging of Jurassic Targets in the North Sea through Improved Imaging of OBN Data

The NOAKA OBN survey was acquired in late 2021 and covers an area of approximately 293 km2 (receiver patch size), it was acquired and processed with the objective of creating a dataset suitable for further field appraisal and development. Targets are situated in the Frigg formation and in Jurassic sandstones, characterised by thin, often faulted layers. These are overlain by younger sediments that can create distortions in the deeper sediments. After a preprocessing sequence going from deblending through to up-down deconvolution, data were binned directly to the common offset azimuth domain and weighted prior to migration to maximize spatial resolution. Diving wave and reflection dynamic matching full-waveform inversion (FWI), combined with bespoke data conditioning designed to mitigate the effect of guided waves in FWI, successfully identified fast geobodies in the shallow section. The final imaging benefited from the use of Q Kirchhoff pre-stack depth migration.