Last November, Shell successfully installed the first 3D printed leak repair clamp in service. Clamps, also known as mechanical leak repair enclosures, are engineered solutions that are used to encapsulate and restore the integrity of operating pipelines against pipeline defects, that arise through time.
According to the Shell, at present, a simple clamp can be manufactured within 3-5 days, but complex clamps may take 4 weeks or more (when factoring in delivery times from the limited number of fabricators specialized in pressure enclosures). The ability to apply temporary repairs is critical to enable facilities to remain on-stream. The availability of essential equipment needs to be maximized in order to reduce production loss and environmental emissions. Given the complexity of piping systems, defects can occur in diverse locations, often triggering the need for dedicated, customized solutions. The speed of response to restore the mechanical integrity and continued safe operation of the asset is critical.
Naturally, 3D printing is a well-suited technology for such applications, and was chosen by Shell for the fabrication of selected clamps. A proof of concept was executed collaboratively by Shell, TEAM, Inc., and Vallourec. Together, the team established a technical specification and inspection test plan for the first clamp with an industrial application to be produced completely with Wire Arc Additive Manufactured (WAAM). The goal was to verify the feasibility of using WAAM to produce clamps for leak repair which will meet the required quality assurance for medium-pressure steam systems. The proof of concept helped gather insights into the steps needed to improve the quality and productivity for future applications.
The 3D printed clamp successfully passed the burst test, which was conducted at 142.4 bar (over 5 times that of the intended design pressure) – satisfying the appropriate level of technical readiness within Shell to qualify the part for a field application.
Unusually, the overall delivery lead time was longer than for a conventionally manufactured clamp, as it was the first product. This was partly due to the high DNV B203 standards for the additive manufacturing of metallic parts (this project started before the publication of the American Petroleum Institute standard API20s). The fact that three sets of clamps were produced for extensive testing, even though only one set was eventually installed, also contributed to the extended production time and increased costs. The team also focussed more on designing the clamp for a 100% success rate in inspection rather than on design optimization, as it was a first-of-its-kind demonstration project.
In addition to all of this, the project involved the shipment of the parts for printing and testing at different locations and countries, which also contributed to the increased lead time and costs – speaking in favor of Shell’s goal of integrated additive manufacturing ecosystems being nearby to operations. The different steps involved in the procurement process as well as quality assurance and quality control account for more than 50% of the time required for the proof of concept.
The next phase will focus on product quality and consistency, as well as reducing the lead time and costs for the additive manufacturing of selected clamps by streamlining the qualification process and reducing the need for duplicable parts. It is intended that future projects will enable the formation of a database with all inspection and qualification test results reflecting the quality variance in WAAM parts; the development of application-specific qualification requirements – allowing more complex parts to be qualified based on case history and successful in-service use cases of simpler parts; and the creation a library of qualified configurations to reduce qualification efforts of same or similar products in the future.
Creating extensive data sets for 3D printing spare parts is resource intensive. Shell believes that process standardization of WAAM technology, specifically in quality control, is paramount to improve lead time and reduce costs, and that this can be achieved by collaborating with interested end-users who have similar needs. Shell also believes that a great leap for the adoption of 3D printing technology in the energy sector can come from such standardization across the industry.