Condeep refers to a make of gravity base structure
Gravity base structure
A gravity-based structure is a support structure held in place by gravity. A common application for a GBS is an offshore oil platform. These structures are often constructed in fjords since their protected area and sufficient depth are very desirable for construction...

 for oil platform
Oil platform
An oil platform, also referred to as an offshore platform or, somewhat incorrectly, oil rig, is a lаrge structure with facilities to drill wells, to extract and process oil and natural gas, and to temporarily store product until it can be brought to shore for refining and marketing...

s developed and fabricated by Norwegian Contractors
Norwegian Contractors
Norwegian Contractors AS was the world leading turnkey concrete gravity base structure supplierin the period of 1974 to 1994. Aker Marine Contractors AS was established in 1995 and is a continuance of the marine activities in Norwegian Contractors AS.Norwegian Contractors AS have worked on...

 in Stavanger
Stavanger is a city and municipality in the county of Rogaland, Norway.Stavanger municipality has a population of 126,469. There are 197,852 people living in the Stavanger conurbation, making Stavanger the fourth largest city, but the third largest urban area, in Norway...

, Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

. 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
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 production in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 and Norwegian continental shelf
Norwegian continental shelf
The Norwegian continental shelf is the continental shelf over which Norway exercises sovereign rights as defined by the United Nations Convention on the Law of the 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.