Pipeline construction methodology is making waves off the coast of Oregon. The HDD Co. recently completed construction on the first phase of an innovative wave energy project for Oregon State University, in Corvallis, Oregon.
PacWave South is a research-based project sponsored by Oregon State University (OSU). The initiative represents the first commercial-scale, utility grid-connected wave energy test site in the United States.
HDD Co. served as the prime contractor on the design-build project, which involved the installation of four subsea 10-in. steel conduits, a short terrestrial pipeline and a large concrete vault that will house electrical and telecommunications hookups for the project, as well as act as a land anchor for the subsea pipelines.
The design team consisted of Jacobs, Macauley Trenchless and Campos EPC, which provided construction management and inspection services.
The jobsite was the parking lot of Driftwood Beach State Recreation Site, about 55 miles west of OSU, where two horizontal directional drilling (HDD) rigs — a Vermeer D750x900 and an American Augers DD-440 — were used to install the subsea cable landings, and a third rig — a Vermeer D220x300 S3 — was used for the terrestrial bore.
HDD Co. was awarded the project in 2019, and construction commenced in Spring 2020, after the design work was completed.
For the subsea portion of the project, HDD Co. completed four bores of 5,200 ft. Holly Pipe Corp. supplied the drill pipe, which featured an 8.625-in. ID and 0.625-in. wall thickness. Bundled high-density polyethylene (HDPE) pipe supplied by ISCO was then pulled through the steel casing provided by Permalok.
In a sense, the four subsea conduits will serve as the extension cord for the wave energy platforms that will be built during the next phase of the project, says Phill Perron, vice president of projects for HDD Co. and project manager for PacWave South.
A 32-in. terrestrial bore of 2,200 ft connects the concrete vault to a secondary site owned by Oregon State. This section of the project involved drilling under a sensitive and protected wetland and encountered some challenging ground conditions.
The boring component of the project lasted 250 days, with each bore costing about $1.2 million. Installation of the four subsea bores, the terrestrial bore and the vault construction was finished on May 13. The total cost of the project was $13 million.
Catch a Wave
The concept of harnessing energy from ocean waves has been around for centuries. The first patent for wave energy was issued in 1799, according to information from the National Renewable Energy Laboratory (NREL).
However, large-scale wave energy projects have run into significant hurdles because of the high cost of development, Perron says. Oregon State funded PacWave South through a $35 million grant from the U.S. Department of Energy’s Water Power Technologies Office, with additional funding from the state of Oregon, donors, foundations and corporations.
“They developed these wave generation machines, and we were contracted for the cable laying and design aspect of the project,” Perron says. “It’s a pretty turbulent area, and the project had to be engineered to withstand the assault and barrage of the waves. PacWave is basically a big sand box for companies to play in as a test space, to explore what actually works for incorporating wave energy into the grid.”
While HDD Co. received the contract for the underground construction portion of the project in 2019, the PacWave project has been in development for about eight years.
OSU submitted a request to the Bureau of Ocean Energy Management (BOEM) for a research lease for the PacWave South project in October 2013. The overall project will consist of four “berths” to support the testing of up to 20 wave energy devices, with an installed capacity of up to 20 megawatts, to demonstrate the viability of wave energy.
The Federal Energy Regulatory Commission (FERC) shares jurisdiction for grid-connected marine hydrokinetic (MHK) projects on the Outer Continental Shelf (OCS).
After years of going through the permitting process, OSU received approval to proceed with PacWave South in early 2021. BOEM issued the required lease on Feb. 16, 2021, and FERC issued a license order for the project on March 1, 2021.
Each aspect of the project featured its own set of challenges for HDD Co., ranging from the length of the bores, ground conditions and logistics.
“Our job was to build out to the wave generation platform, which is located a couple miles offshore,” Perron says. “We had four bores to connect power and data lines through a steel casing. If we were to do it all as one bore, it would have needed to be 72 in.”
Perron adds that HDD Co. performed the four subsea bores without using the intersect method, meaning that the drilling had to be done “slow and steady.” The company drilled 12-in. diameter holes with 14-in. back reams. Brownline was used for the steering for part of the shore approaches.
“We were only reaming at 14 in., but the risk of fracking out was a concern,” Perron says. “It took more time than we anticipated, and it was a sensitive environment.”
Aside from the length of the bores, another challenge was accounting for migrating sand dunes, Perron says. HDD Co. had to study the waves and patterns of these dunes to map out where the sand was going to be during construction and when the cables are eventually connected to the wave generation platforms.
Weather was another challenge, with rapidly changing patterns and a tight timeframe for construction.
“Working on the coast, we had to complete the subsea bores by October, or the window closes until January,” Perron says. “Plus, the weather changes every 48 hours, so we had to get as much work done as we could in the time we had.”
Weather also impacted the use of divers on the project, who would verify where the pipe punched out of the ocean floor, says David Kodokian, assistant construction manager on the PacWave project for HDD Co.
“One of the challenges with the weather was when we were putting divers in the water,” Kodokian says. “We wanted to give them the best conditions possible, and of course we are installing this facility that’s conducive to wave energy, so there is quite a bit of turbidity where they were diving.”
With the concern about subsea conditions and the integrity of the pipe, corrosion control was a major factor in the project. Protective coating provided by Womble Co. Inc. was applied on the inside and outside of the pipe, and HDD Co. hired industry veteran Roy Rodger to design and implement the cathodic protection on the project.
The project resulted in an innovative solution that HDD Co. is working on patenting, called a “Beavertail,” which is a valve fitting connected to the bull nose at the end of the subsea product pipe. During conduit storage and drying operations, the Beavertail will keep sea water out of the conduit regardless of whether vacuum or pressurize-depressurize drying methods are used. When the cable is ready for installation, the conduit will be pressurized until the Beavertail’s rupture disk bursts. Once ruptured, the Beavertail will release the pressurized medium, providing an indicator of the conduit’s location. The Beavertail was named in honor of Oregon State’s mascot.
During the terrestrial boring operations, HDD Co. crews encountered a couple challenges related to the ground conditions.
“We ran into a serious channel of cobble and gravel, which was left over from the glacial period,” Perron says. “This alluvial channel made it incredibly difficult to intersect and maintain circulation. We were also working in a sensitive wetland where fracking out just was not an option.”
The majority of the drilling was through Nye mudstone, which Perron describes as a “unique” and “challenging formation” composed of clay, silt and fine sand-like particles. When drilling through it, the mudstone swells and can increase the annular pressure well outside the limits of the pressure envelope, while also increasing the risk of an inadvertent return (IR).
HDD Co. used two steering methods for the terrestrial bores, Inrock and On Point HDD.
The concrete vault is the “largest cable landing vault in the world,” Perron says. The vault itself cost about $1.6 million to build.
“The bores connect to a massive five-bay vault with a central chamber,” Perron says. “Usually these vaults are small, but two or more people could stand in each bay of this one.”
Supply chain shortages were another challenge facing the project. However, during his 10-year career in the Royal Canadian Air Force, Perron had experience in this area.
“All my training was going off in my head,” he says. “With building materials, we would buy it all at once. We built kit BOMs [bill of materials] for different stages of the project, so our only issue was storage. How we approached that absolutely saved the project.”
Despite this planning, Perron adds that there were still some problems related to the availability of certain raw materials.
With a project involving five to six crews, plus several service providers and consultants onsite, as well as the continuous presence of representatives from Oregon State, communication was a major factor in the project’s success, says James Lirot, construction project manager at Campos EPC LLC, one of HDD Co.’s subcontractors.
“Lack of communication can be a problem on a project like this,” Lirot says. “The critical nature that communication plays, especially when having the client on site perpetually, there is a constant need for relaying information so the stakeholders understand if there are any problems.”
Lirot says his role was to serve as an intermediary between OSU and the construction crews, helping the client understand the construction processes and techniques.
Kodokian agrees about the importance of communication, especially among the construction crews.
“Managing all the different crews, they have to be able to cooperate with each other and ensure success with each other,” Kodokian says. “At times, they have to help each other out. It requires organization and communication among every party.”
Kodokian stresses the importance of direct communication and planning meetings.
“So many things went right, and I have to attribute that to our planning,” Kodokian says. “Many times, we sat down with the engineers and stakeholders for hours at a time. A lot of problems can be solved outside of email. We always try to involve all team members in any onsite project challenge. You get the problem solved quicker that way, and you may find a better solution. It all boils down
Adapting to Trends
As the global energy industry trends toward lowering greenhouse gas emissions, other HDD and pipeline contractors could see more projects like PacWave South, according to Romeo Shiplee, P.E., director of geotechnical engineering for Campos EPC.
“I think this project is important to the industry as a whole because of the implementation of this trenchless technology into another subsector of the market,” Shiplee says. “We are now doing things on the renewable energy side of the market that were seldomly if ever used in the past especially in this size and scale. This has huge potential for the business as more and more of the world is moving toward renewables.”
For the installation of the subsea conduits and the terrestrial lines, HDD Co. relied on its experience in other sectors, such as energy pipeline construction and telecommunications. Perron hopes the success of the PacWave project will have a positive impact on the energy construction industry and pave the way for large-scale HDD and pipeline contractors.
“For these projects that involve boring 6,000 to 7,000 ft without an intersect, you need contractors with more engineering experience,” Perron says. “With PacWave, involving large-diameter cable landings, this sets the standard for pipeline contractors in the future. With the renewable energy space, looking at solar, wind and hydrogen, you connect these things with pipelines. That’s the dirty secret with renewables.”