Antarctic Treaty System An Assessment: Proceedings of a Workshop Held at Beardmore South Field Camp, Antarctica, January 7-13, 1985 (1986) / Chapter Skim
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17. Arctic Offshore Technology and Its Relevance to the Antarctic
17. Arctic Offshore Technology and Its Relevance to the Antarctic
Pages 245-264
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From page 245... ...
The Arctic Ocean can be considered a polar Mediterranean -- an inland sea with very little communication, except through the Fram Strait, with the other oceans of the world. It is a hostile region, but because of the populated, surrounding land masses, human presence around the 245
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From page 246... ...
Canadian government sources predict mean potential recoverable reserves of oil for the Canadian Beaufort of about 8.5 billion barrels; for the Arctic Islands, about 4.3 billion barrels; and for the Canadian east coast, about 12 billion barrels. On the Alaskan continental shelf, a mean value for potential recoverable reserves is about 818 billion.
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From page 247... ...
Close to shore, out to about 20 m water depth and between islands, the ice becomes landfast each winter. The approximate demarcations among the various ice zones in the winter in the Beaufort Sea are shown in Figure 17-2; this is typical of most of the coastal regions of the Arctic Ocean.
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From page 250... ...
In addition to pack ice, there are many icebergs off Canada's east coast. The major source of icebergs in the eastern Arctic is the Greenland ice cap, which annually calves about 240 km3 of glacier ice into the surrounding seas.
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From page 251... ...
~C,, ~ 0 — ICE CUTTER — SEMI SILT ISLANDS RCRAFT BARGE FAST ICE (WINTER ONLY) 74-='>~ LOCAL ICE THICKENING ~ ~ ' 1 ' -' ' ' ~ OPEN WATER DRILLSHIP DRILL BARGES 1 00 700 FIGURE 17-4 Exploratory drilling concepts for ice infested waters (Croasdale, 1983)
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From page 253... ...
Islands have proved very adequate in resisting the ice, but their cost effectiveness decreases with water depth. In water depths beyond about 20 m the fill requirements tend to be prohibitive, especially for in the summer islands with very shallow slopes.
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From page 254... ...
254 ol .~ o ~q tn UJ U)
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From page 255... ...
Also of significance is that at its present location no foundation preparation was done; it was put down directly onto the seafloor. It is also worth noting that at this location Exxon will be building a spray-ice barrier to provide additional sliding resistance against late winter ice.
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From page 256... ...
For most of the year the drill ships remain unused in a winter harbor. To extend the floating drilling season, the Gulf subsidiary Beaudrill designed and built a round drill ship, the Kulluk (Figure 17-9)
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From page 257... ...
MAIN DECI ELEVATION (FEET) ~ - ~ 1 HULL TANKS 1 ~ FIGURE 17-9 Typical cross section of Kulluk, showing mooring wire routing (Frankovich, 1984)
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From page 258... ...
In the near-shore Beaufort Sea it is expected that artificial islands and/or bottom-founded steel or concrete structures will be used. Fixed platforms in ice-covered regions are probably feasible out to 100 m water depth.
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From page 259... ...
~ ~ Am, ~ / / / / '7 GRAVITY CONE OR MONOPOD ISLANDS l / '/'// / / / / j A-/ _ SUBSEA PRODUCTION o l 6 20 100 WATER DEPTH ( m) 7a 0 FIGURE 17-10 Production concepts for ice infested waters (Croasdale, 1983)
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From page 261... ...
All the drilling has been performed using either drill ships or semisubmersibles during the pack ice free periods. However, during the ice-free periods, icebergs can still occur, and techniques for dealing with them have been developed.
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From page 262... ...
Drilling off the landfast ice and ice shelves; and (2) Floating drilling in the summer months combined with iceberg management, including quick disconnects from a protected subsea wellhead.
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From page 263... ...
89. Dome Petroleum Limited, ESSO Resources Canada Limited, and Gulf Canada Resources Limited.
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