Gas Hydrate CSEM Mapping Campaign Completed in Japan
Ocean Floor Geophysics Inc. in cooperation with Fukada Salvage and Marine Works, has completed its third high-resolution controlled source electromagnetic (CSEM) survey of near-surface gas hydrates using the Scripps Institution of Oceanography Vulcan system in Japanese waters. The survey was conducted for the National Institute of Advanced Industrial Science and Technology.
Following the successful CSEM surveys and 3D inversion models completed in 2014 and 2015, the 2017 survey comprised over 413 line km of high-resolution data collected in depths up to 1640 m from the Fukada vessel Shin Nichi Maru. A 3D inversion of the EM data for the entire 2017 survey area has also been completed and delivered to the client.
The Vulcan system is a highly flexible CSEM system capable of a depth of investigation of up to 1 km. This depth of investigation can be increased to a depth of several kilometers with the addition of seafloor receivers. The data processing and inversion workflow uses mature and well tested computer codes developed at Scripps and at the University of British Columbia.
OFG is a world leader in the commercial deployment of deep-water marine electromagnetic systems. OFG in cooperation with Fukada can also now deploy an AUV-based CSEM system that is a complement to the towed Vulcan system for the mapping of gas hydrate deposits and submarine massive sulfide (SMS) deposits. Together, the towed source Vulcan system and the seafloor transmitter-based AUV CSEM system provide a tested sea-ready capability to map seafloor resistivities in multiple exploration scenarios.