Subsea success for geobor core sampling

2008 May 07

Drilling contractor Fugro Seacore has successfully completed a challenging project to extract core samples in soft rock more than 800 metres below the seabed. S Geobor, the Atlas Copco sampling system, played a keyrole in the project.

It was a dramatic and technically challenging assignment that faced the underwater drillers from Fugro Seacore as their eight-leg vessel ‘Excalibur’ positioned itself in the Irish Sea about 30 km off the north-west coast of England.

The goal was to produce high quality core samples far beneath the seabed as part of a proposed project to build sub-surface gas storage caverns. The challenges included choosing the right casing sizes, preventing the mud from damaging the cores and avoiding potential shallow gas deposits.

After drilling down to 205 mbml (metres below mud level), the team started coring using an S Geobor oversize bit (OD 197 mm) inside a 9 5/8″ casing. The operation extended down to 865 mbml, producing 60 m of core with a 97 percent core recovery, successfully achieving the objective.

Epiroc operated under the trademark “Atlas Copco” prior to January 1, 2018.