A conductor tensioner unit is installed on an offshore jackup rig

Jackup rig

A jack-up rig is a type of mobile platform that is able to stand still on the sea floor, resting on a number of supporting legs. The most popular designs use 3 independent legs, although some jackups have 4 legs or more...

 to apply upward tension on the conductor. The conductor tensioner is installed into the conductor deck and is usually removable in order to protect the unit during transit.

The drilling conductor is the first and outer tubular which runs from the drilling rig

Drilling rig

A drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...

 into the seabed

Seabed

The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...

. It is usually installed by drilling a hole into the seabed, then running the tubular into the hole and cement

Cement

In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

ing to the seabed. It can also be installed by driving with a pile hammer.

Why are conductors tensioned?

• Allows smaller surface conductors such as 9 5/8” or 13 3/8” to be used in any water depth. This results in a significant well cost savings, particularly for exploration.
• Allows the larger conductor sizes (say 20” and 30”) to be used in greater water depths.
• Prevents large cyclic tensions from being induced in conductors when large wave forces are applied. The conductor tensioner applies a “spring” force to the top of the conductor pipe
  Conductor pipe
  The Conductor Pipe is a large diameter pile that is set into the ground to provide the initial stable structural foundation for a borehole or oil well....
  
  .
• The tensioner prevents overload of the conductor deck compared to a jacking system without accumulators.

Manufacturers of Conductor Tensioners

• Tensa Equipment
• ICON Engineering
• National Oilwell Varco
• Control Flow, Inc.

External links

• Tensa Equipment
• ICON Engineering
• National Oilwell Varco
• Control Flow, Inc.