Harmonizing welding of subsea equipment
DNV Recommended Practice DNV-RP-B204 Welding of subsea production system equipment harmonizes welding requirements for pressure-retaining equipment within wellheads, Xmas trees, manifolds and jumpers (Figure 1).
It aims to improve on the current practice of major operators having company-specific requirements for such welding, in addition to requirements in API, ASME and ISO standards. The many project-specific welding qualifications involve significant lead time and cost. They also create uncertainty during tenders and project execution, as suppliers are prevented from standardizing tenders and manufacturing processes.
DNV-RP-B204 ensures high quality welds and consistent, repeatable fabrication processes. It lowers the cost and time involved by reducing project uncertainty and non-value-added work, and decreases the amount of qualification work performed in each project.
The JIP is continuing to extend the scope of the recommended practice to additional applications within subsea production systems.
Simplifying risk assessment for subsea pumping systems
Another DNV Recommended Practice, DNV-RP-F303 Subsea pumping systems, complements existing industry standards for such systems. It specifies normative and informative technical requirements for an entire subsea pumping system with pressure rating up to 1,035 bar (15,000 pounds per square inch) and water depths down to 3,000 metres. It applies to single phase, hybrid, and multiphase pump types.
The recommended practice aims to provide a comprehensive specification for subsea pumping systems, simplifying risk assessment and increasing the reuse of qualified technology. It seeks to reduce cost, and give predictability and confidence in a subsea pumping system. It also serves as a contractual reference document between purchaser and supplier, offering recommended roles and responsibilities among parties in the value chain to increase efficiency.
Standardized interfaces could be the next big frontier in subsea
Standardization involving whole subsea systems could gain impetus from a trend towards digitalization and electrification in the sector. Operators plan to operationalize all-electric solutions in frontrunner subsea projects from 2020. A new DNV GL study4 predicts that if implementation challenges are solved, all-electric will be applied to greenfield developments in sensitive areas and in deeper waters towards 2030, before becoming the mainstream option. “The industry now has normative standards and design codes for most of what it designs and engineers,” said Neil Brown, innovation & technology manager – Norway, UK & Canada, for subsea engineering, construction and services company Subsea 7. “Hardware and software interfaces for whole subsea systems could be the next big frontier in subsea standardization.”