TGS, a global leader in energy data and intelligence, in collaboration with joint venture partner Viridien, has announced the successful completion of the multi-client Heimdal Terrace Ocean Bottom Node (OBN) project and the delivery of the final processed data.
The Heimdal Terrace OBN survey, the first of two multi-client dense OBN surveys acquired in the North Sea in 2023, spans 426 sq kms in a mature region that includes the Balder and Ringhorne fields as well as near-field exploration acreage.
Conducted from April to June 2023, the survey employed up to three node handling vessels, two triple-source vessels and four support vessels. The data acquisition resulted in 28,814 node positions and nearly 1.2 million shot points, providing an extensive new dataset for the region.
The data underwent advanced processing and imaging techniques to achieve the survey objectives, including deblending, noise attenuation, up-down deconvolution, and pre-stack depth migration. A velocity model was generated using least-squares diving-wave full-waveform inversion (FWI) followed by time-lag FWI, utilizing the full recorded wavefield, including refractions, reflections, diving waves, ghosts, and multiples, to capture subsurface detail at all depths.
The imaged data shows substantial improvement in resolution and structural clarity over previous datasets, offering crucial insights into the region’s complex geology and reservoirs. This enhanced imaging, including depth-time conversion, will be valuable to explorers operating in the area for years to come.
The Heimdal Terrace OBN, available now, is supported by industry funding.
Source: TGS
