Metal 3D Printing Provides Design Freedom in Geothermal Energy Application

Downhole Emerging Technologies
Houston, TX
www.det-ofs.com

Protolabs
Maple Plain, NM
www.protolabs.com

Geothermal energy has the potential to substantially offset the world’s oil and gas usage, but the first hurdle is developing the equipment capable of extracting energy safely and efficiently from underground environments as hot as 700 °F.

To spur innovation in this field, the Department of Energy (DOE) sponsored the American-Made Geothermal Manufacturing Prize, a $4.65 million competition. With a special focus on 3D printing, the contest aimed to motivate innovators to address the challenges associated with operating sensitive equipment in harsh geothermal environments. Teams would develop, test, and revise prototypes using additive manufacturing (AM) to support the advancement of geothermal tools and technologies.

Houston-based startup Downhole Emerging Technologies (DET) took home the $500,000 grand prize in the competition for the development of a packer system, which is used in much the same way as a plumber uses a plug to regulate or stop the flow of water. A packer (or plug) for industry applications can be used in all types and sizes of casings and tubes.

DET Co-Founder and CEO Ken Havlinek admitted if it weren’t for the DOE competition, AM of the packer would not have been his first choice. Like many in the emerging geothermal market, Havlinek’s background is in the oil industry where he said there is a lack of awareness around 3D-printing capabilities. “Like myself, the experts that are working on these geothermal challenges don't necessarily appreciate or understand the value that additive manufacturing can bring,” he added.

With the help of funding from the DOE program, the Diamond ETIP (Extreme Temperature Isolation Packer) went from concept to working prototype in under two years. The system works somewhat like an accordion-type structure, or a crushed soda can — the motion of the packer in that fashion is what is used to seal itself within the tube or casing. The primary goal was to develop a packer system that was easily deployable and retrievable.

Accomplishing this mission came down to the internal features of the ring design. While one would assume it is hollow within the ring’s outer walls, the design under the surface allows the packer system to deform in the most efficient manner. These features lead to less force required to compress and stretch the ring while getting the same deformation and performance out. AM offered the design freedom for the team to get creative and push the features of the structure beyond what machining could achieve.

“Without those features, it would have taken a lot more energy to get the job done and we wanted to use as little energy as possible to achieve the full range of motion required during the operation of the packer system,” Havlinek said. “The smallest amount of force required, the better. Thanks to additive manufacturing, we were able to reach our design targets.”

Direct metal laser sintering (DMLS) was the additive solution that provided the durable materials necessary for geothermal energy applications. Inconel 718, 316L, and 17-4 stainless steels provided adequate hardness, strength, and corrosion resistance. Havlinek called on the quick-turn capabilities offered through digital manufacturing to meet the DOE contest’s deadlines.

Protolabs recently partnered with GE Additive to add the X Line 2000R printer at its Raleigh, N.C., 3D-printing facility for large-scale metal printing jobs like what was required with DET. An early DMLS iteration of the sleeve for the tool was produced in Inconel 718 on the machine and ended up being the tallest DMLS 3D-printed part ever made at Protolabs, coming in at 19 inches (482.6 mm) tall and with an outer diameter of more than 4.7 inches (119.4 mm). Post-processing on each part included stress relief and some machining to thread each end of the part.

Other smaller parts made on GE Additive M2 machines were expansion rings, some single and some stacked up together as one part in smaller pieces. Some were done in stainless steel 316L and some in 17-4 iterations. Each part was solution annealed and cut off from the 3D printer using Electro Discharge Machining (EDM); the 17-4 parts, specifically, went through H900 surface hardening.

In total, five iterations and 20 prototypes were developed for DET.

Hard work and rapid prototyping paid off for DET. The company was one of two grand prize winners recently of the DOE manufacturing competition. Future development will include additional building, testing, and iterating with Protolabs as DET moves the tool toward a market launch. “There’s a lot of work now between innovation and marketplace,” said Havlinek. “DOE and its work to spur innovation helped get us started and now we are working to get our invention advanced enough to go and find a company to start using it.”

As for a timetable, Havlinek said DET is aiming to have its tool fully developed and ready for market launch by the end of 2023.

This article was written by Eric Utley, 3D Printing Application Engineer at Protolabs (Maple Plain, MN). For more information visit here .

---