Condeep (abbr. concrete deep water structure) refers to a make of gravity base structure
for oil platforms developed and fabricated by Norwegian Contractors in
Stavanger, Norway. A Condeep usually consists of a base of concrete oil storage
tanks from which one, three or four concrete shafts rise. The original Condeep
always rests on the sea floor, and the shafts rise to about 30 meters above the
sea level. The platform deck itself is not a part of the construction.
The
Condeep is used for a series of production platforms introduced for crude
oil and natural gas production in the North Sea.
Following the success
of the concrete oil storage tank on the Ekofisk field, Norwegian Contractors
introduced the Condeep production platform concept in 1973.
This
gravity base structure for platform was unique in that it was built from reinforced
concrete instead of steel, which was the norm up to that point. The platform
was purpose made for the heavy weather conditions and the great water depths
found in the North Sea.
Troll A
The Troll A platform is
the largest Condeep to date. It was built over a period of four years, using
a workforce of 2,000, and deployed in 1995 to produce gas from the enormous Troll
oil field.
With a total height of 472 meters, Troll A was the largest
structure ever to be built and moved. The total weight when launching was
1.2 million tons. 245,000 m³ of concrete and 100,000 tons of steel for reinforcement
were used. The amount of steel corresponds to 15 Eiffel towers. The platform
is placed at a depth of 300 meters. For stability, it is dug 35 meters into
the sea floor. |
