What is air gap in jack-up rig?

The bottom of the hull must have a large enough air gap that the largest wave crest will not hit the hull and turn over the rig. Air gaps usually are 35 to 50 ft, with the larger air gaps in shallower water, because wave heights build as water depth decreases.

Where does a jack-up rig typically drill?

Jack-up rigs are used to drill wells in shallow waters, typically less than 400 ft of water, and can be used to drill wells to a Total Depth (TD) of 30,000–35,000 ft. Due to their mobility, jack-up rigs can be used to drill exploration wells, appraisal wells, and development wells.

How deep can a jack-up rig go?

Jackup rigs can only be placed in relatively shallow waters, generally less than 120 metres (390 ft) 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 150 to 190 meters (500 to 625 feet).

What is preloading in jackup?

Preloading operation is to apply loads on the legs of the jack-up to a pre-determined load level to ensure that the soil resistance is sufficient for the foundation to resist the maximum design loads (includes environmental loads) for operational in that location.

How many jack-up rigs in the world?

Jackup rigs are a type of oil rig platform. They are mobile platforms that rise over the sea level, primarily used in offshore oil drilling. The source depicts that the global number of jackup rigs on contract increased gradually since October 2018 and is projected to have amounted to 355 in December 2019.

What is rig punch through?

Punch-through is a sudden and uncontrolled penetration of the spudcan often causing structural damage of the unit. It may occur when the load becomes equal to bearing capacity for the spudcan while within a soil layer having relatively higher bearing capacity than the soil underlying that layer.

How much does a drillship cost?

Drillship newbuilds range from $550 million to $1.2 billion for VDLs ranging from 15,000 and 24,000 tons and displacements between 45,000 to 112,000 tons, in part reflecting differences in oil storage capabilities.

Who owns the biggest oil rig?

The world’s biggest offshore drilling companies

  • Schlumberger – $32.8bn.
  • Halliburton – $23.99bn.
  • Baker Hughes – $22.9bn.
  • Petrofac – $5.83bn.
  • Weatherford – $5.74bn.
  • China Oilfield Services Limited (COSL) – $3.17bn.
  • Nabors Offshore – $3.05bn.
  • Transocean – $3.01bn.