32
Y. Fouquet and D. Lacroix
Offshore oil drilling equipment is now able to control drill bits 6 km from the
seabed. Vessels can control mobile vehicles attached to them positioned thousands
of metres below the surface, and sometimes in difficult sea conditions. To visually
explore the deep-sea environment, humans are now capable of operating in a completely obscure environment in which every square centimetre is crushed under half
a tonne of water.
Whether on land or at sea, only four methods are available for collecting minerals: surface scraping, excavation, digging tunnels to access subsurface deposits
and drilling into and fluidising the deposit. The difference with deep-sea mining is
that operations must be carried out underwater, and are controlled remotely from a
floating surface platform. At each stage in the process, according to the nature of the
deposit, the mass handled diminishes and waste is discharged.
To date, no long-lasting commercial operations to collect solid minerals have
been carried out at depths of over 200 m; however the first trials conducted in 2010
by Nautilus Minerals with polymetallic sulphide collection systems at depths of
1,700 m, where the sulphides were easily detached from the seabed, showed that,
from a technical point of view, nothing is currently preventing the exploitation of
this type of deposit.
The progress made in terms of deep-sea drilling, trench digging and oil production capacities have considerably extended the range of technical resources available, however these resources must undergo major modifications to be suitable for
the more selective extraction procedures required for harder mineral deposits.
With the notable exception of those applied to diamond mining, most deep-sea
exploration and exploitation techniques were originally designed for shallow waters
and their use was gradually extended to respond to needs. It is therefore necessary, in
order to fill the gaps, for techniques applicable to deep waters to be developed by perfecting traditional systems, many of which are borrowed from other industrial sectors.
Results and Recommendations
Results
The conclusions are distinguished by mineral type and by related site.
Hydrothermal Sulphides
The exploration and potential exploitation of hydrothermal sulphides will be the focus of all challenges: geopolitical (for international waters), within the framework of
the introduction of ISA permits; environmental, with probable conflicts over site protection and exploitation conditions; scientific (volcanic and tectonic processes, rock
and fluid geochemistry, specific metallogeny, biological resources…) and economic.
Y. Fouquet and D. Lacroix
Offshore oil drilling equipment is now able to control drill bits 6 km from the
seabed. Vessels can control mobile vehicles attached to them positioned thousands
of metres below the surface, and sometimes in difficult sea conditions. To visually
explore the deep-sea environment, humans are now capable of operating in a completely obscure environment in which every square centimetre is crushed under half
a tonne of water.
Whether on land or at sea, only four methods are available for collecting minerals: surface scraping, excavation, digging tunnels to access subsurface deposits
and drilling into and fluidising the deposit. The difference with deep-sea mining is
that operations must be carried out underwater, and are controlled remotely from a
floating surface platform. At each stage in the process, according to the nature of the
deposit, the mass handled diminishes and waste is discharged.
To date, no long-lasting commercial operations to collect solid minerals have
been carried out at depths of over 200 m; however the first trials conducted in 2010
by Nautilus Minerals with polymetallic sulphide collection systems at depths of
1,700 m, where the sulphides were easily detached from the seabed, showed that,
from a technical point of view, nothing is currently preventing the exploitation of
this type of deposit.
The progress made in terms of deep-sea drilling, trench digging and oil production capacities have considerably extended the range of technical resources available, however these resources must undergo major modifications to be suitable for
the more selective extraction procedures required for harder mineral deposits.
With the notable exception of those applied to diamond mining, most deep-sea
exploration and exploitation techniques were originally designed for shallow waters
and their use was gradually extended to respond to needs. It is therefore necessary, in
order to fill the gaps, for techniques applicable to deep waters to be developed by perfecting traditional systems, many of which are borrowed from other industrial sectors.
Results and Recommendations
Results
The conclusions are distinguished by mineral type and by related site.
Hydrothermal Sulphides
The exploration and potential exploitation of hydrothermal sulphides will be the focus of all challenges: geopolitical (for international waters), within the framework of
the introduction of ISA permits; environmental, with probable conflicts over site protection and exploitation conditions; scientific (volcanic and tectonic processes, rock
and fluid geochemistry, specific metallogeny, biological resources…) and economic.