Longer tiebacks, deepwater construction, increased production, and integrity issues on aging assets are just a few of the challenges facing the subsea sector as it matures and exploits deepwater and ultra-deepwater fields. The deeper and further north the industry goes, the bigger the problems become. The changing operating conditions demand equipment with superior functionality, performance, and reliability.

The challenges have been set, and experts are taking this chance to deliver technology that has never before been implemented. Extensive R&D is being undertaken to maximize and extend the life of current fields.

FMC supplied subsea equipment for Statoil’s ?sgard field in the Norwegian North Sea, the largest subsea development at the time of its completion. (Image courtesy of FMC Technologies)

Striving for solutions

Since the late 1990s, flow assurance and the challenges associated with the move to deep water have dominated the subsea umbilicals, risers, and flowlines industry.

These challenges have led to new technologies such as Technip’s electrically trace-heated pipe-in-pipe (ETHPiP) design, which provides a low-power solution that compliments reel-lay installation. The company’s Evanton spool base in Scotland was developed to accommodate ETH-PiP assembly and is an example of how the North Sea has provided an arena for transferring groundbreaking technology to the worldwide subsea industry.

AIVs, AUVs, and ROVs will increasingly play an important role in the subsea environment. (Image courtesy of Subsea 7)

Umbilical and riser technology also has undergone changes as companies have contended with flow assurance, fatigue, access for inspection, and total installed cost. Investment has been made in developing bundled and single hybrid towers, steel catenary risers, and flexibles. And composite technology, which is in a relatively early stage of development, will no doubt make its mark soon as well.

As many pipelines and subsea wells reach the end of their planned lifespan or even exceed it, they require regular servicing. New and innovative technologies to lower the cost of pipelines over their lifetime could offer significant savings. Pipelines made of composite material and coatings that will not corrode and are less prone to blockage should offer increased pipeline and riser reliability.

The move into harsh geographical areas like the Arctic has brought the use of conventional hydraulic systems under scrutiny because of environmental issues and has led the industry to set targets to decrease hydrocarbon releases. To contend with this challenge, the use of all-electric christmas trees is being considered as a possible solution, although the technology is in the very early stages of development and acceptance.

Exploration in deep water and ultra-deep water is becoming more dependent upon autonomous inspection vehicles (AIVs), AUVs, and ROVs. These vehicles will increasingly play an important role, for example, using ROVs deployed concurrently on different sections of a project to deliver better efficiency.

The design of these vehicles has evolved in recent years. A fiberglass monocoque construction now offers a more compact, rigid, strong, and lighter ROV that is more energyefficient and can be deployed for longer periods of time.

AUVs also are undergoing heavy R&D, with the goal of extending the nonstop record of 31 km (19 miles) a target. Improvements in nontethered vehicles are allowing AUVs to break boundaries in exploring further under ice sheets.

Integral to the success of technology over long distances is underwater positioning surveys and sonar systems. These are becoming more widely specified for exploration, construction, and production operations. Recent history has seen simple monotone pulse and frequency shift-keyed technology deployed for underwater communication.

As the move to new frontiers has progressed, issues such as inadequate signaling and the inability to work over long ranges have arisen. Because developments from acoustic systems and integration with inertial navigation systems have become prominent for a range of positioning and measurement (such as spool metrology), applications have been designed to overcome signaling issues.

Technip’s ETH-PiP technology provides a low-power solution that complements reel-lay installation. (Image courtesy of Technip)

Common language

It is crucial that consistency and common standards be established as new technologies are introduced. Adopting a common standards policy such as the new Energy Institute guidelines helps the industry better deal with reliability, which improves efficiency and safety. Today different manufacturers use different interface protocols when developing subsea control systems, a situation that complicates integration. Industry standardization must go farther to ensure across-the-board regulation with new technologies.

Subsea 7’s Seven Borealis is the industry’s newest pipelay/ heavy-lift vessel designed to overcome the challenges of ultra-deep water. Created through a conversion project carried out jointly with the original designers, the vessel’s 600-metric-ton Slay system and 1,000-metric-ton J-lay tower provide a more stable environment for pipelay operations. A series of anti-heel and anti-roll systems ensures greater stability for vessels working in harsh environments. (Image courtesy of Subsea 7)

The role of the UK in frontier areas

The North Sea has long been recognized as the test bed for subsea technologies and services, and as a mature province, it will continue to be the seat of subsea learning. The UK will continue to pioneer and internationalize new skills, technologies, and expertise into frontier areas. Subsea UK is committed to promoting opportunities in emerging markets and disseminating the technological expertise of the UK subsea industry with the goal of extending subsea technology into frontier areas.

Keeping ahead of the game in terms of R&D is more important than ever, and Subsea UK will continue to assist its members to lead the challenge of pioneering new technology and expertise.