Condeep

{{Short description|Make of gravity based oil platform structure}}

Condeep is a make of gravity-based structure for oil platforms invented and patented by engineer Olav Mo in 1972,{{Cite web|title=Norwegian Industrial Property Office|url=https://search.patentstyret.no/Patent/19721541/135909?caseIndex=0}} which were fabricated by Norwegian Contractors in Stavanger, Norway.Fagerberg; Mowery; Verspagen, p.192Mehta, Povindar K. p.4Gerwick, Ben C. p.166 Condeep is an abbreviation for concrete deep water structure. A Condeep usually consists of a base of concrete oil storage tanks from which one, three or four concrete shafts rise.Dr. techn. Olav Olsen, [http://www.npd.no/Templates/OD/Article.aspx?id=3514 Condeep platforms] {{Webarchive|url=https://web.archive.org/web/20110927164326/http://www.npd.no/Templates/OD/Article.aspx?id=3514 |date=2011-09-27 }}, (in Norwegian) 2011, web page by Norwegian Petroleum Directorate, retrieved 2011-08-30 The Condeep base 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 and Norwegian continental shelf.

Following the success of the concrete oil storage tank on the Ekofisk field, Norwegian Contractors introduced the Condeep production platform concept in 1973.Arentsen; Künneke p. 90

This gravity-based structure for a platform was unique in that it was built from reinforced concrete instead of steel, which was the norm up to that point. This platform type was designed for the heavy weather conditions and the great water depths often found in the North Sea.

Condeep has the advantage that it allows for storage of oil at sea in its own construction. It further allows equipment installation in the hollow legs well protected from the sea. In contrast, one of the challenges with steel platforms is that they only allow for limited weight on the deck compared with a Condeep where the weight allowance for production equipment and living quarters is seldom a problem.

Troll A

The Troll A platform is the tallest Condeep to date.Fagerberg; Mowery; Verspagen, p.191 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 {{convert|472|m}}, Troll A was the tallest object that has ever been moved to another position, relative to the surface of the Earth. Many sources incorrectly state that it was also the largest structure of any kind to be moved but the Gullfaks C was in fact heavier. The total weight of the Troll A Condeep when launching was 1.2 million tons. 245,000 m³ of concrete and 100,000 tons of steel for reinforcement were used.{{cite web |title= Guinness World Records - tallest offshore gas platform | work=Guinness World Records | year= 1996| url=http://www.guinnessworldrecords.com/records/science_and_technology/buildings/largest_offshore_gas_platform.aspx}} 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.

Gullfaks C

Gullfaks C rests {{convert|217|m}} below the sea surface and has a total height of {{convert|380|m}}.[http://en.structurae.de/structures/data/index.cfm?ID=s0003250 Structures] Gullfaks C was the heaviest object that has ever been moved to another position, relative to the surface of the Earth with a total displacement between 1.4 and 1.5 million tons.{{Cite web|url=https://www.guinnessworldrecords.com/world-records/467630-heaviest-man-made-object-moved|title = Heaviest man-made object moved}}

Condeep platforms

class="wikitable sortable"

! Structure

! Depth

! Operator

! Year

Beryl A Condeep

| align="right" | 120 m

| Mobil

| 1975

Brent B Condeep

| align="right" | 140 m

| Shell

| 1975

Brent D Condeep

| align="right" | 140 m

| Shell

| 1976

Frigg TCP2 Condeep

| align="right" | 104 m

| Elf

| 1977

Statfjord A Condeep

| align="right" | 146 m

| Mobil

| 1977

Statfjord B Condeep

| align="right" | 146 m

| Mobil

| 1981

Statfjord C Condeep

| align="right" | 146 m

| Mobil

| 1984

Gullfaks A Condeep

| align="right" | 135 m

| Statoil

| 1986

Gullfaks B Condeep

| align="right" | 142 m

| Statoil

| 1987

Oseberg A Condeep

| align="right" | 109 m

| Norsk Hydro

| 1988

Gullfaks C Condeep

| align="right" | 216 m

| Statoil

| 1989

Draugen Condeep

| align="right" | 251 m

| Shell

| 1993

Sleipner A Condeep

| align="right" | 82 m

| Statoil

| 1993*

Troll Condeep

| align="right" | 303 m

| Norske Shell

| 1995

Nawy, Edward G. Chapter 13.7

Gerwick, Ben C. p.515

The original concrete structure of Sleipner A sank during trials in the Gandsfjord on August 23, 1991. A new structure was built, and deployed in 1993.

Sources

{{Cite book |title=Innovation, Path Dependency, and Policy: The Norwegian Case |first1=Jan |last1=Fagerberg |first2=David C. |last2=Mowery |first3=Bart |last3=Verspagen |publisher=Oxford University Press US |year=2009 |isbn=978-0-19-955155-2}}
{{Cite book |title=Concrete construction engineering handbook |first=Edward G. |last=Nawy |publisher=CRC Press |year=2008 |isbn=978-0-8493-7492-0}}
{{Cite book |title=Concrete in the marine environment |first=Povindar K. |last=Mehta |publisher=Taylor & Francis |year=1990 |isbn=978-1-85166-622-5}}
{{Cite book |title=Construction of marine and offshore structures |first=Ben C. |last=Gerwick |publisher=CRC Press |year=2007 |isbn=978-0-8493-3052-0}}
{{Cite book |title=National reforms in European gas |first1=Maarten J. |last1=Arentsen |first2=Rolf W. |last2=Künneke |publisher=Gulf Professional Publishing |year=2003 |isbn=978-0-08-043687-6}}

References

Category:Oil platforms