Aquaterra and Plexus Introduce New Riser System

Aquaterra Energy and Plexus Holdings have developed a light weight, dual barrier HPHT riser system which can be deployed by a jack-up to enable an alternative to semi-submersible installation for HPHT well operations.

The technology is suitable for shallow water depths up to 150 meters and harnesses the combined capabilities of the company’s subsea technologies.

By uniting Aquaterra Energy’s HPHT riser system and Plexus’ POS-GRIP wellhead engineering technology, an inner riser string is installed inside a conventional high pressure riser (HPR) to span the gap between a dry surface BOP and a wet subsea tree. It provides full 20,000 psi capability and utilities all metal-to-metal gas tight seals on both the external and internal riser string.

Ben Cannell, product line manager, Riser and Conductor Solutions with Aquaterra Energy, said: “The innovation carries with it the potential to change the industry’s default position of selecting semi-submersible rigs for developments in water depths up to 150 meters, which today make up over 60% of all subsea developments worldwide. It renders the use of jack-up rigs in such scenarios both feasible and attractive in both a technical and commercial context.”

Craig Hendrie, technical director, with Plexus Holdings, added: “This is a new, technology-led drilling proposition to the international market and is one that directly addresses the industry’s cost-reduction agenda. Amid the ever-increasing industry focus on HPHT operations, this methodology represents an innovative and cost-effective alternative while maintaining safety, integrity and operational performance.”