Compliant Tower
Encyclopedia
A compliant tower is a fixed rig structure normally used for the offshore production of oil
or gas
. The rig consists of narrow, flexible (compliant) towers and a piled foundation supporting a conventional deck for drilling and production operations. Compliant towers are designed to sustain significant lateral deflections and forces, and are typically used in water depths ranging from 1,500 and 3,000 feet (450 and 900 m). At present the deepest is Baldpate in 580 m of water.
With the use of flex elements such as flex legs or axial tubes, resonance
is reduced and wave forces are de-amplified. This type of rig structure can be configured to adapt to existing fabrication and installation equipment. Compared with floating systems, such as Tension-leg platform
s and SPAR
s, the production risers are conventional and are subjected to less structural demands and flexing. This flexibility allows it to operate in much deeper water, as it can 'absorb' much of the pressure exerted on it by the wind and sea. Despite its flexibility, the compliant tower system is strong enough to withstand hurricane conditions.
The first tower emerged in the early 1980s with the installation of Exxon's Lena oil platform.
H-851. The Base Tower makes up the first 250 metres of the more than 400 metre high tower. The crane vessel that is partly visible is the Thialf
. This is the heaviest compliant tower installed to date and the first outside of the Gulf of Mexico.
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
or 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...
. The rig consists of narrow, flexible (compliant) towers and a piled foundation supporting a conventional deck for drilling and production operations. Compliant towers are designed to sustain significant lateral deflections and forces, and are typically used in water depths ranging from 1,500 and 3,000 feet (450 and 900 m). At present the deepest is Baldpate in 580 m of water.
With the use of flex elements such as flex legs or axial tubes, resonance
Resonance
In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...
is reduced and wave forces are de-amplified. This type of rig structure can be configured to adapt to existing fabrication and installation equipment. Compared with floating systems, such as Tension-leg platform
Tension-leg platform
A Tension-leg platform or Extended Tension Leg Platform is a vertically moored floating structure normally used for the offshore production of oil or gas, and is particularly suited for water depths greater than 300 metres and less than 1500 meters...
s and SPAR
SPAR (platform)
A spar, named for logs used as buoys in shipping and moored in place vertically, is a type of floating oil platform typically used in very deep waters. Spar production platforms have been developed as an alternative to conventional platforms...
s, the production risers are conventional and are subjected to less structural demands and flexing. This flexibility allows it to operate in much deeper water, as it can 'absorb' much of the pressure exerted on it by the wind and sea. Despite its flexibility, the compliant tower system is strong enough to withstand hurricane conditions.
The first tower emerged in the early 1980s with the installation of Exxon's Lena oil platform.
Launching of Benguela Belize Base Tower
On April 15, 2005 the Base Tower of Benguela Belize was launched from the bargeBarge
A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods. Some barges are not self-propelled and need to be towed by tugboats or pushed by towboats...
H-851. The Base Tower makes up the first 250 metres of the more than 400 metre high tower. The crane vessel that is partly visible is the Thialf
SSCV Thialf
SSCV Thialf is a semi-submersible crane vessel operated by Heerema Marine Contractors, the largest crane vessel in the world.-History:SSCV Thialf was constructed in 1985 as DB-102 for McDermott by Mitsui Engineering & Shipbuilding Co., Ltd...
. This is the heaviest compliant tower installed to date and the first outside of the Gulf of Mexico.
See also
- Petronius
- BaldpateBaldpate (oil platform)Baldpate is a 1901.9 feet tall offshore compliant tower oil platform near the coast of Louisiana. Baldpate Platform was designed by Hudson Engineering in Houston, Texas, and installed by Heerema Marine Contractors.-External links:* *...
- Oil platformOil platformAn 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...