Statoil West Elara HP Riser

2H Offshore recently joined forces with sister company Claxton Engineering on their project to provide a rental HPHT riser system to Statoil for drilling and completing wells on the Gullfaks field offshore Norway.

The combination of 132m water depth, 7000psi pressure and the harsh North Sea environment presented a significant and unique challenge for drilling and completing wells from the heavy duty jackup rig West Elara. The project involved a number of Acteon group companies working together, including: 2H Offshore, Claxton Engineering, Subsea Riser Products, and Pulse Structural Monitoring.

2H Offshore provided the engineering analysis for the project during the engineering phase. The initial analysis of the proposed riser arrangement showed the considerable challenges in achieving acceptable strength and fatigue performance with the existing HPHT riser technology on this development. 2H worked alongside Claxton, SRP and Statoil to develop the riser design to achieve the target fatigue life and operability criteria set by Statoil. This was achieved through careful design of the SRP flanged riser joints and use of VIV suppression technology.

Due to the potential for rapid fatigue accumulation, Statoil requested a monitoring system to allow them to measure the HP riser responses in real-time during operations. 2H worked with Pulse to develop an on-line monitoring system which enabled Statoil’s objectives to be met. This included both the instrumentation hardware and the DrillASSURE software system to provide real-time processing of measured data, including fatigue accumulation and loading on the HP riser and tensioning system. 2H also provided additional processing of the measured response data to demonstrate the validity of the analytical models of the riser system to Statoil.

The HP riser operations on Gullfaks have now been successfully completed and 2H are now working closely with Pulse and Statoil on a follow up monitoring campaign for the West Elara on the Valemon Field.