ABERDEEN, UK --Claxton Engineering has supplied an unusual riser support system to the Magellan drilling rig for use in workover operations in the UK North Sea.
The GlobalSantaFe-owned rig, working on Shell's Shearwater field, needed the support to control the deflection of the workover riser caused by horizontal movement of the rig relative to the fixed jacket platform. The aim was to limit loadings on the surface tree as well as on the riser, as part of the ultimate goal of maximizing operational rig time.
Claxton says its solution is unusual as it applies to the rig's horizontal movement, rather than vertical. Also, it provides soft restraint via a combination of hydraulic dampers and compensating weights. The hydraulic elements allow the riser to deflect along with the rig as a result of differential movement between the rig and the platform.
The system has been in service since February, and has performed to expectations.