Jackup Rig

jmpl|A jackup oil rig.
jmpl|Jackup elevated on its legs
Hiji **jack-up rig** atawa hiji unit anu bisa naék sorangan *(self-elevating)* nyaéta jenis anjungan usik anu diwangun tina lambung ngambang dilengkepan kalayan sajumlah suku nu bisa usik,is a type o fitted with a number of movable legs, sanggup naékeun lambung di luhureun permukaan sagara. Lambung apung matak unit bisa ngangkut sarta kabéh mesin kapasang ka lokasi anu dipikahayang. Sanggeus di lokasi lambung ditaékkeun nepikeun ka posisi anu diperlukeun di luhur permukaan sagara dirojong ku sukuna anu nicak kana dasar sagara. Suku ti unit éta bisa dirarancang pikeun nembus dasar sagara, bisa dilengkepan bagéan rada ngagedéan atawa mangrupa pondasi. Umumna rig Jack-up henteu bisa maju sorangan gumantung kana kapal atawa kapal angkat beurat pikeun transportasi.

Anjungan Jack-up dipaké minangka anjungan pengeboran eksplorasi sarta layanan anjungan leupas basisir. Jackup platforms have been the most popular and numerous of various mobile types in existence. Anjungan Jack-up usik geus jadi anu pangpopulérna sarta sagala rupa jenis. Total jumlah rig Jack-up 'Pangeboran' anu operasi baris kira-kira 540 dina ahir taun 2013.

## Ngaran 
Jack-up rigs are so named because they are self-elevating—with three or four movable legs that can be extended (“jacked”) above or below the hull. Jack-ups are towed to the site with the hull, which is actually a water-tight barge that floats on the water’s surface, lowered to the water level, and the legs extended above the hull. When the rig réaches the drill site, the crew jacks the legs downward through the water and into the séa floor (or onto the séa floor with mat supported jack-ups). This anchors the rig and holds the hull well above the waves.

## Operasi 
A jackup is a floating barge fitted with long support legs that can be raised or lowered. The jackup is maneuvered (self-propelled or by towing) into location with its legs up and the hull floating on the water. Upon arrival at the work location, the legs are jacked down onto the séafloor. Then "preloading" takes place, where the weight of the barge and additional ballast water are used to drive the legs securely into the séabottom so they will not penetrate further while operations are carried out. After preloading, the jacking system is used to raise the entire barge above the water to a predetermined height or "air gap", so that wave, tidal and current loading acts only on the relatively slender legs and not on the barge hull.

modérn jacking systems use a rack and pinion géar arrangement where the pinion géars are driven by hydraulic or electric motors and the rack is affixed to the legs.

Jackup rigs can only be placed in relatively shallow waters, generally less than  of water. However, a specialized class of jackup rigs known as premium or ultra-premium jackups are known to have operational capability in water depths ranging from 500 to 625 feet.

## Tipe 
### Mobile offshore Drilling Units (MODU) 
This type of rig is commonly used in connection with oil and/or natural gas drilling. There are more jackup rigs in the worldwide offshore rig fleet than other type of mobile offshore drilling rig. Other types of offshore rigs include semi-submersibles (which float on pontoon-like structures) and drillships, which are ship-shape vessels with rigs mounted in the centers. These rigs drill through holes in the drillship hulls, known as moon pools.

### Turbine Installation Vessel (TIV) 
This type of rig is commonly used in connection with offshore wind turbine installation.

### Barges 
Jackup rigs also refer to specialized barges that are similar to an oil and gas platform but are used as a base for servicing other structures such as offshore wind turbines, long bridges, and drilling platforms.

File:NewCarissa dismantled by KarlissaA and B July 2008 panorama merge.jpg|Jackup barges being used to dismantle a ship that was wrecked at séa.
File:Scroby Sands Wind Farm 2981489897.jpg|Jackup barge servicing a Vestas V80-2MW wind turbine of the Scroby Sands wind farm.

## Tempo ogé 
* Crane vessel
* TIV Resolution

## Tumbu kaluar 
* Jackup Units: A technical Primer for the Offshore Industry Professional

## Référénsi