Riser system

Claxton Engineering Services has installed a high-pressure drilling riser system for Premier Oil’s Catcher area field development in the UK’s Central North Sea.

The latest installation is part of a contract secured in 2014 for the field, which includes the development of the Catcher, Varadero and Burgman fields in block 28/09a.

Claxton Engineering Services project engineer Owen Lewis said: "Each joint was forged from a single billet of material with no joining welds, which makes the riser stronger than traditional systems.

"The riser’s fatigue life far exceeds the duration of the drilling phase of this project. We also provided optimum deployment times for the riser package, through the use of hydraulic handling tools and bolt tensioning equipment."

As part of the work, Claxton provided the subsea connector to bolt the riser with the subsea wellhead. In addition, it has also provided the riser tensioning interface from the riser to the rig’s tension system.

"The riser’s fatigue life far exceeds the duration of the drilling phase of this project."

The company also provided all riser handling tools and a suite of custom-designed bolt tensioners to aid flange make-up.

The riser analysis for the Catcher development was provided by 2H Offshore, a sister company of Acteon.

Lewis said: "Claxton succeeded in delivering a unique guide frame design attached to the stress joint, which provided consistent and repeatable positioning of the tubing hanger in the wellhead."

Premier Oil operates the field and holds a 50% stake. Other partners include Cairn Energy and MOL Group, with 30% and 20% stakes respectively.

The field was discovered in August 2010, followed by Varadero and Burgman in January 2011 and March 2011 respectively.


Image: Claxton installing a new fully forged drilling riser system in the North Sea. Photo: courtesy of Claxton Engineering Services Ltd.