Definition - What does Tensioner System mean?
Tensioner System, also known as riser tensioner system, is a set of devices used in offshore drilling operations by drilling vessels to provide a near constant upward force on the drilling riser independent of the movement of the floating drill vessels. The riser is connected to the wellhead on the seabed and therefore the tensioner must manage the differential movements between the riser and the rig. If there were no tensioner and the rig moves downward, the riser would buckle. Similarly, if the rig rises then high forces will be transmitted to the riser and it would stretch and be damaged.
Petropedia explains Tensioner System
Riser Tensioner systems are critical in offshore drilling operations. Tensioner systems traditionally have used wireline assemblies arranged around the drill floor and substructure, but this arrangement can result in a congested moon pool. Wireline riser tensioning systems also have other disadvantages such as:
- Maximum capacity is limited from a practical point of view by wire and sheave diameters,
- These systems are maintenance intensive (wire maintenance, cut and slip).
- Handling the wire while doing cut and slip operations is difficult, especially for the larger wire sizes.
Some of the advantages of tensioner systems over traditional wireline systems are that they have lower cost, direct control of the riser, less long-term maintenance, system redundancy and simple designs.