Definition - What does Telescoping Derrick mean?
A Telescoping Derrick, also known as Mast or telescoping mast, is a telescopic type pyramid-shaped structure above the rig floor where the crown block, monkey board and racking board are supported. The crown block is a set of pulleys through which the drill line (wire rope) passes to another set of pulleys in the travelling block and travel up and down in the derrick with or without the drill string.
Petropedia explains Telescoping Derrick
Telescoping Derricks come with different heights and capacities and offer good strength to weight ratio. They are designed as per the API specifications. There are various types of oil derricks / masts which a derrick manufacturer provides. They are:
- Jackup rigs or static derricks – These derricks are static and are not movable from one place to another. Once fixed they remain at their position.
- Dynamic Derricks – These derricks can be easily moved to any location on the onshore site.
- Dual Derricks – These types of derricks are basically used when ultra deep water drilling has to be performed. They have two drilling units on one hull.
- Dual offset Derricks – These types of derricks have derrick tower asymmetrical about its z axis in both x and y directions and provide a unique drill floor arrangements.