Published: September 2001 | IBC Conference, “Technological Advances in Risers, Moorings & Anchorings in Deepwater Fields” | September 18 – 20, 2001 | London, England
Abstract
Offshore exploration for oil and gas is being performed in even more challenging waters, with fields being developed in water depths of 2000 metres and greater. To recover hydrocarbons from these depths a number of technical challenges are presented to the designers of riser and offloading systems. In addition, metocean characteristics and relatively low reservoir temperatures also compound the challenges.
Flexible pipe is a proven solution for conveying fluids from subsea wells to surface vessels in 2000 metres water depth. Solutions are being developed for service in up to 2500 metres. It is now the centre of focus for large diameter offloading systems in deepwater applications particularly in West Africa where significant volumes of crude oil are to be offloaded to other floating structures and tankers.
This paper discusses how Wellstream’s unbonded flexible pipe technology has overcome the challenges of floating production systems in 2000 metres water depth and how its continued development will ensure its incorporation in new pioneering solutions for ultra-deepwater riser systems.
These achievements in technology are applied to the design of large diameter offloading and export systems which are being considered for large field developments. An insight into the design and detailed analysis of the unbonded flexible pipe solutions developed by Wellstream for large diameter export riser systems is provided.
Finally, the paper concludes with an update of the comprehensive full-scale testing program currently ongoing at Wellstream’s global facilities.
Authors:
Tuohy, J., Sheldrake, Dr. T., Williamson, D.