Justin Tuohy Publications

The Offloading Solution for Hydrocarbons in Deepwater – Offshore West Africa

Published: 2001 | The Journal of Offshore Technology

“Unbonded Flexible Pipe is a viable cost effective solution for the transportation of hydrocarbons from Floating Production, Storage and Offloading (FPSO) vessels to CALM Buoys for tanker transport to shore” – Justin Tuohy, Director, Product Strategy for Wellstream.

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. Since unbonded flexible risers are an obvious solution for floating production and storage systems, being a proven technology spanning three decades, these challenges have already been overcome for the smaller diameter pipe structures. In 1999 Wellstream illustrated the technology lead by being the first manufacturer of flexible pipe to qualify 4-inch and 6-inch internal diameter products to 2000 m water depth for offshore Brazil. Continued developments will have much larger internal diameters qualified to these water depths in the near future………

Justin Tuohy Publications

Offloading Systems for Deepwater Developments: Unbonded Flexible Pipe Technology is a Viable Solution

Published: 2001 | Offshore Technology Conference | April 30 – May 3, 2001 | Houston, Texas, USA

Abstract

Offshore exploration for oil and gas is being performed in even more challenging waters, with fields being developed in water depths of 2000 meters and greater. To recover hydrocarbons from these depths, a number of technical challenges are presented to the designers of riser and offloading systems. Met-ocean characteristics and relatively low reservoir temperatures compound the challenges.
This paper discusses how unbonded flexible pipe technology has overcome the challenges of floating production systems in 2000 meters water depth and how its continued development enables solutions for ultra deep water riser systems. During the discussion of the status of flexible pipe technology, an overview is given to the advancements in flow
assurance technology and integrity monitoring, both of which can evolve as integral parts of the flexible pipe.
These achievements in technology are applied to the design of large diameter offloading and export systems that are being considered for large field developments where crude oil
is being offloaded to other floating structures and tankers. The paper details the design and detailed analysis of the unbonded flexible pipe solutions developed by Wellstream to overcome the deepwater challenges associated with large diameter export riser systems. Design comparisons are developed with the alternative products currently proposed.
Finally, the paper concludes with an economic appraisal of why flexible pipe systems should be considered a cost effective solution in the overall CAPEX and OPEX of deepwater field developments.

Authors:

Tuohy, J., Loper, C., Wang, Dr. D.