TDI-Brooks, under contract to TGS, has completed the offshore multibeam phase offshore the Niger Delta.
This survey took place in water depths of 750 to 3,500 metres.
It is also Nigeria’s first regional multi-client multibeam and seafloor sampling study.
TDI-Brooks’ R/V Gyre acquired 82,000 square kilometres of high-resolution hull-mounted multibeam echo sounder data.
The multibeam data campaign detected a total of 1,223 active hydrocarbon seeps in the multibeam water column data.
Near real-time hydrocarbon seep analysis took place onboard the vessel in order to expedite the process of core selection.
The R/V Proteus is up next to begin acquisition of the follow-up surface geochemical exploration (SGE) coring campaign in July 2020.
Specifically, it will collect some 245 piston core samples targeting suspected seep features selected from the MBES dataset, along with an additional 45 additional piston core samples for geotechnical and biostratigraphic studies.
The campaign will also collect an additional 17 surface heat flow measurements.
Surface geochemical exploration
Modern SGE campaigns utilise integrated approach to identify seepage on the seafloor, pinpoint core locations, as well as accurately characterize geochemical results.
The science and art of this seep hunting involves:
(1) proper selection of core sites from the geophysical records;
(2) safe and skilled acquisition of seabed cores at these exact sites;
(3) analytically distinguishing promising samples from samples with varying levels of natural background concentrations, and also
(4) properly interpreting the geochemical results in a geologic context.