Harmonizing oil and gas industry requirements for steel forgings would enable more consistency and repeatability, and better quality of components vital to the safe, clean and efficient functioning of subsea equipment.

“This is really about efficient project execution,” said ExxonMobil’s Dr Brian Newbury, speaking as chair of a DNV GL-led joint industry project (JIP) that is complementing Recommended Practice (RP) DNVGL-RP-0034 Steel forgings for subsea applications. The RP is aimed at reducing delivery time, engineering and production costs, and at improving material quality of forgings.

Newbury explained that large forgings are typically “the pacing item” for subsea tree delivery. If a tree is delayed, there can be significant knock-ons for overall project execution. Drill rigs often run USD1 million or more per day, and drilling costs are typically the largest portion of a subsea project budget. The efficiency of contracting, mobilization and rig utilization decides if a project comes in on budget therefore.

“If operators cannot optimize drilling schedules, or have to mobilize or demobilize rigs due to subsea equipment availability, there are huge negative amplifying effects well beyond the price of a subsea tree, much less an individual forging,” he added. “Previously, vendors have had limited pre-stocking programmes due to variability in what operators required in both material specifications and quality oversight.”

Hans Christian Ly, head of materials technology for global engineering contractor Aker Solutions, put it another way: “Harmonized requirements would reduce cost levels as we could trust that the industry would use the RP, which will then gain higher volumes.”

Accordingly, Phase II of the ongoing JIP aims to establish harmonized quality management and surveillance requirements for forgings to support further the stocking philosophy. This phase is expected to be completed in December 2016.

By spring 2016, Aker Solutions was among the majority of JIP participants who have implemented the RP. “We have used it to standardize our set-up of materials in our enterprise resource planning system,” Ly said. “When a project comes up, we are prepared to use it.”

Progress on quality requirements shows participating operators, vendors and forgemasters aligning with the goal of consistent levels of quality oversight, Newbury reported.

“This is an important accomplishment,” he commented. “Achieving alignment from the major operators to remove direct oversight of critical forgings manufacturing, coupled with vendors’ and forgemasters’ commitment to provide consistent quality oversight across the industry, enables this strategy. We are currently working to define these quality requirements for qualification of forgemasters and production surveillance.”

Solving the trust challenge
Ly identified trust as a key challenge to the RP becoming more widely adopted in the industry. “We still need to build more trust into the supply chain. Otherwise, we could see the number of hold and witness points, and documentation, remain as high as today.”