With the industry focused so heavily upon improving production performance and efficiency, the requirement to better monitor the condition of subsea pipes, risers and flowlines to avoid potential failures and the dreaded threat of downtime is a must. This rings even more true since they are usually attached to high-value production assets such as FPSO vessels and mobile offshore production units.

In the technical session “Advances in Flexible Pipe Technology” held on Monday morning, a number of speakers focused on the latest understanding of the material behaviors of flexible pipe, how inspection technologies can be applied to better manage risks during operation and on improving confidence in the suitability of flexibles for challenging design applications such as ultradeep water and hydrogen sulfide.

There are plenty of opportunities in particular for better monitoring of subsea risers. According to BPP-TECH’s Tony Kenyon, there will be an inventory of between 1,950 and 3,090 subsea flexible risers between 2014 and 2021.

Kenyon outlined his company’s efforts to develop an in situ radiographic inspection solution for nondestructive examination of subsea flexible risers. The Digital Radiographic Inspection of Flexible Risers Tool (DRIFT) is initially being used by Subsea 7, said Kenyon, to inspect risers while in operation. DRIFT is appropriate for at least three-quarters of the above forecast number of subsea risers, he said.

“What you see is what you have got,” said Kenyon, outlining how the DRIFT “crawler” equipment travels along the flexible pipe, supported by an attendant ROV. The equipment scans the pipe for any potential fractures or other defects and delivers enhanced images.

Another speaker, Dr. Vineet Jha of GE Oil & Gas Wellstream, highlighted that the use of composite reinforcement on unbonded flexible pipe for optimized hybrid designs could have major weight-saving benefits. Outlining a “toolbox approach” to the design of unbonded flexible pipe systems, he told the audience that “in deepwater you could save up to 70% in buoyancy requirements,” which would also naturally reduce costs in deepwater applications as a result.

The addition of composite technologies to the design of unbonded flexible pipes also increases the ability to create bespoke designs for a range of applications, he added.

Offshore