PAPUA NEW GUINEA – Diamond drillers in search of a challenge should know about how SEACORE has drilled and recovered core samples from the massive sulphide deposits on the floor of the Minas Basin. Seacore, based in Cornwall, England, did the work at the Solwara project, owned by PLACER DOME OCEANIA and Vancouver-based NAUTILUS MINERALS.
The Solwara project is believed to be one of the world’s first detailed commercial drilling and sampling programs of mineral-rich, seabed sulphide deposits. The deposits are formed in mounds and hydrothermal vents or chimneys, produced by deep convection circulation of seawater generated by submarine volcanic activity.
Seacore used its own heave-compensated R100 drill rig mounted onto the chartered multi-service construction vessel DP Hunter to provide the drilling and sampling services. Seacore also used a special drill string and suite of drilling tools for the taxing contract. Over 30 boreholes were completed and samples taken from up to 20 metres in the seabed, 1,700 metres below the surface.
“This was one of Seacore’s most challenging projects,” says the company’s exploration division commercial and contracts manager Mark Richards. “We were operating in water over a mile deep and coupled with the sea floor topography, with its collapsed hydrothermal chimneys, surrounded by precipitous sedimentary mineral deposits, made it challenging to implant the drill bit. This tricky operation was helped by previous high definition 3-D topographical mapping of the seabed and, in some instances, the use of an ROV (remotely operated vehicle) with a camera, supplied by the client. Despite the enormous challenge, the project was very successful and we anticipate other similar exploration projects, which we hope Seacore will be involved with.”
The cores recovered by Seacore were initially assessed on the DP Hunter prior to a more extensive detailed study onshore to gauge the commercial viability of mining the sea-floor sulphide deposits. Marine biologists were also onboard the DP Hunter to document the biological observations and recovered materials as part of an environmental study of the area.
Readers having a need for non-oilfield marine drilling expertise should visit www.Seacore.com.