JOGMEC, the Japan Oil, Gas, & Metals National Corporation, used the D/V Chikyu to acquire pressure cores through a potential marine gas hydrate reservoir this summer. The pressure cores were recovered by Aumann Associates Inc., using a new pressure coring tool (the Hybrid PCS) that recovers cores up to 3.5 m long. Geotek's PCATS (Pressure Core Analysis & Transfer System) was used to transfer, analyse and subsample 35 m of core recovered under pressure. After X-ray CT imaging and non-destructive analysis under in situ pressures, over 60 samples between 10 cm and 120 cm long were cut and stored for further detailed on-shore analysis by scientists.
With up to nine Geotek staff at sea at a time, this was a major expedition for Geotek! The new pressure coring system and the upgraded version of PCATS (350 bar, 3.5 m cores) worked exceptionally well. PCATS Triaxial, a geotechnical testing cell that can accept pressurized samples directly from PCATS, was also used successfully on this expedition, providing the first ever triaxial shear strength, permeability and resonant column data from gas hydrate cores that had been maintained at in situ pressures.