Keeping oil-and-gas processing operations running smoothly is widely acknowledged to be among the toughest challenges in any industry. Critical process-control components inevitability fail under the stresses of the high pressure, severe service conditions in the O&G environment. Historically, O&G operations have had to implement expensive inventory programs because average manufacturing lead times are incompatible with operational needs, to avoid the risk of an extended shutdown: parts needed from inventory often are the same ones selected when the operations was first designed, and replacements may no longer be available from the manufacturer. Opportunities to upgrade a component design or materials as operating requirements change, or next-generation designs are introduced, are limited at best. As a result, reliability problems continue and, in some cases may worsen over time.
Compounding these issues, many sites are located in remote or difficult-to-access locations — offshore, the Arctic — that make service and field support problematic. How can you reliably and quickly provide critical parts to distant and remote locations unless you have stockpiles of inventory at every one?
AM potential… and obstacles
O&G operators have become increasingly open to considering metal additive manufacturing (AM, aka 3D printing) as an answer to such challenges. Not surprisingly, original equipment manufacturers (OEMs) to the industry also are looking to AM as, along with their operator-customers, they evolve to achieve more efficient, cost-effective solutions to inventory and geographic roadblocks.
Still, there remain some significant obstacles to widespread adoption of AM in the O&G industry.
Most of the established metal-AM technologies require extensive knowledge of printing parameter development, which can be a labor-intensive process and may result in challenges to adapt efficiently and rapidly to changing geometries and design features. Often these systems also require parts to be significantly re-designed in order to be printable. Additionally, data from throughout the printing process is often unavailable, and it can be critical in assessing the finished quality of a part.
What’s more, a print file set up on one AM machine cannot be used on another machine — sometimes, even if both machines are the same make and model — without user intervention; the result can be an ever-changing file based on individual machine calibration. This creates a digital inventory challenge similar to the current physical inventory one that O&G operators are already dealing with.
There also have been, until very recently, no published guidelines from the American Petroleum Institute (API) for procuring or specifying AM materials. “This has been a challenge for users interested in applying more advanced industrial AM technology to applications where the speed and quality it can deliver would be beneficial,” according to Steve Freitas, R&D director at IMI Critical Engineering. That British company designs, manufactures, and installs customized, highly engineered flow-control products for new plants and provides comprehensive plant lifecycle service.
API guidelines for AM
However, guidance is here now in the form of API20S, the first-ever O&G industry-sanctioned specification for metal AM. Published on October 19, 2021, API20S spells out processes, testing, documentation, and traceability among other requirements for manufacturers of metal AM components being used in O&G facilities of all types.
The API20S was drafted with input from hundreds of companies, from operators to OEMs to AM machine manufacturers. While it does not detail complete success criteria (i.e., required mechanical or non-destructive testing acceptance criteria), API20S outlines the kinds of testing and validation that will be required depending on different risk levels within an O&G operation.
IMI Critical welcomed the guidelines enthusiastically, as several years ago they began looking at different AM systems to 3D print valves several years ago. “But it’s only recently that we’ve identified the advanced AM technology that really delivers on its promise,” Freitas said.
Partnership to production
VELO3D is the AM-system manufacturer that is providing the level of advanced AM technology needed at IMI Critical. Partnering with a major O&G operator that is also an API committee member, IMI Critical has delivered highest criticality (Additive Manufacturing Specification Level 3), First-Article component-builds intended for field service. The parts, which also meet API20S requirements, were printed on a VELO3D Sapphire AM system operated by contract manufacturer Knust-Godwin.
VELO3D is known for its full-stack AM solution that includes automated pre-build system calibration and end-to-end build-quality monitoring and reporting — features that deliver exactly the kind of data on which many of the objectives of API20S are based. The long-term goal of the joint project is to build up a compendium of measured field data that will support the path toward certification of production parts for AM, as well as the future establishment of more exact specifications for material properties and test methods.
The more immediate benefits of IMI Critical’s work with VELO3D became clear as the project progressed from idea to working parts.
How’d they do that?
For the team project, the O&G operator selected a commonly installed choke valve cage. The part had been manufactured with simple slotted holes for ports, which can have problems with vibration and damage due to trim erosion in high-pressure-drop operations.
The flow-control industry has evolved considerably since the time this legacy part was created. One innovation is IMI Critical’s industry-leading technology improvement, DRAG®, which consists of an array of discrete, multi-stage flow paths that achieve better control fluid velocity and prevent problems with vibration and trim erosion.
IMI Critical, having produced metal AM components for years, saw a business opportunity not only in replacing a part “on-demand”, but also to improve its performance with DRAG.
The next step was to assess the new design for 3D printing in Inconel 718. “VELO3D ’s early review of our cage design produced valuable recommendations on how to improve the quality of both the as-built AM part and the final, post-processed machined part,” according to Freitas.
Getting ready to print
With the completed CAD design for the part, it was now time to move to additive manufacturing. Unlike other metal AM printing systems, VELO3D ’s Flow print-preparation software automatically responds to a part’s geometry without any complex part-specific parameter development. Flow does this by applying a generalized set of recipes based on the design’s native CAD geometry and user-defined inputs relating to surfaces of importance. This allows design engineers to focus on their desired end-part functionality above all, without the need for complex, pre-print parameter manipulation.
The designer also can use the software to easily apply and test different surface-refining sub-processes, to choose the best one. This not only resulted in a quick transition into the First-Article section of the project, but it also created a standardized framework to ease setting up future builds to meet IMI Critical’s specific surface-finish and flow-characteristic requirements.
“Flow greatly reduces the initial set-up time from CAD to print file,” confirmed Zach Walton, director of Energy Solutions for VELO3D, who worked closely on the project with IMI Critical.
He continued: “This opens up the ability for design and manufacturing engineers to more easily and efficiently implement metal AM printing. At the same time, our system’s ability to print the same build file on any Velo Sapphire machine, no matter where it is in the world or who is operating it, was very appealing to the O&G operator’s vision for digital inventories and direct part replacement.”
Quality control—and reproducibility
With API20S requirements always in mind during the project, the automation provided by VELO3D ’s internal quality-control software, Assure, was highly beneficial. “Following one-click calibration before a build, Assure compiles that data along with a tremendous amount of information collected throughout the build, layer by layer, then automatically generates a build report containing the information of importance,” Walton said.
“The raw data and height-mapper images also were useful for evaluating and assessing critical areas of the part for future production. In conjunction with the Flow pre-print software, this allows for this same print file to be printed on any VELO3D system no matter who is operating it or where it is in the world—with the same expected end-part quality. These capabilities of advanced AM now make digital warehousing and on-demand part replacement achievable.”
Knowing that the print file created during the project can be re-printed on any VELO3D system anywhere now provides tangible support for the development of more robust supply chains, as oil-and-gas operations start leveraging metal AM to replace or improve legacy parts.
“Now we can help our customers reduce inventory requirements while providing opportunities to optimize both the functional characteristics and the materials of critical process-control components,” Freitas said. “This allows O&G operators to shift their focus away from repair and part supply-chain problems and concentrate on improving plant reliability and controlling costs.”
The two First Article choke valve components were printed successfully at the Knust Godwin facility. From there, the valves were removed from the build plate along with the API20S test specimens. Then, the valves were machined to final finish while specimens were tested according to API20S, which showed compliance to IMI Critical’s materials specification.
Next, the valves were flow tested at IMI Critical before being delivered to the O&G operator for use in upcoming field trials. “This was the first production valve produced using Velo3D technology and the flow test results were a profound demonstration of the consistency of the generalized processes provided by Flow software,” Freitas said.
As noted, in-field testing is imminent and the goal of bringing similar AM successes to the industry continues to broaden. “IMI Critical has a vision to offer its operator-customers much more than just legacy-part replacement,” Walton related. “They really want to move existing capabilities forward by continuing to replace outdated parts with updated technology that provides optimal performance.”
IMI Critical is finding that operators whose legacy OEMs can no longer replace those aging designs are becoming more open to technologies, like DRAG and AM—but they also are demanding those new parts as quickly as possible.