Originally authored by Carter Haydu and reposted with permission: https://www.dailyoilbulletin.com/article/2020/9/30/hydrostatic-testing-pipelines-could-be-switched-to/

Removing the hydrostatic test and replacing it with alternative solutions could maintain safe pipelines in Canada, while also being better for the environment and more cost effective for industry, suggests one Avatar Program team’s presentation to a panel of industry experts.

Hydrostatic testing is a process used to test tanks and pipes for leaks by pressurizing the vessel or piping, and then monitoring pressurization levels. If the pressure lowers, then there is a leak within the system. In terms of oil and gas pipeline construction, according to the Avatar team’s presentation, hydrostatic testing is simply ineffective.

“We do acknowledge the test verifies if the pipe will withstand a higher pressure than it will see during operations, and it checks if the pipe performs under this higher pressure,” said Deba Eigbe, program manager, Digital Twin, at TC Energy Corporation. “However, when you statistically analyze the hydrostatic results over recent decades, data shows it’s increasingly unlikely for modern pipeline systems to fail hydro tests.

“You may be surprised to know that even pipes with material defects have passed this test. I would add that there’s an inconsistency in what the test confirms, and how pipelines in operations actually fail.”

While the test confirms material strength at weld seams, pipeline incidents typically are not due to excessive pipe fluid pressure, he said. Engineering can mitigate such risk. One reason hydrostatic testing is increasingly useless is due to significant contemporary manufacturing advancements, as well as enhancements to quality-control processes. Since pipe-welding technology has improved, Eigbe added, the test is essentially obsolete. It is also water intensive.

“Hauling billions of cubic metres of water from a water source to a field location, often times remote, increases our environmental footprint. Where required, a simple gaseous leak test is a viable replacement.”

Finally, he noted, industry already has implemented successful piloting of enhanced lifecycle quality processes, offering alternatives to hydrostatic testing. “There’s huge potential here, and that’s what really excites us to pursue this at a broader level. The sky is the limit here.

“We just have to be intentional, deliberate and collaborative with all of the different stakeholders, making sure we listen to people’s concerns, making sure we deploy a mutually beneficial approach. If we do this in a phased approach, then I think it could go as far as we want it to.”

Indeed, eliminating the test significantly reduces water consumption for pipeline construction, noted Bertus Vos, co-founder and principal engineer at BlueFox Engineering Inc.

“We believe this will become a significant global environmental responsibility of energy leaders in the future,” he said, adding reduced overall construction schedules put pipelines into service sooner and at lower installation costs, and at reduced carbon footprints by eliminate water transportation for testing and then for proper water disposal. “These reductions result in an overall improvement of our environmental performance and social licence to operate pipelines.”

Test replacement

The Avatar team proposes replacing the hydrostatic test only where applicable, according to Vos, and to be clear, he said, doing so is not always applicable.

“We propose a whole lifecycle quality management, which starts at the engineering phase and is carried through to construction, manufacturing and finally operating, so that we can improve building upon pipeline manufacturing and engineering techniques,” Vos added. “We improve the entire quality lifecycle approach.”

Michael Abate, construction engineer and Enbridge Inc., noted it is not necessarily applicable to replace this test on all older pipelines. “We think that rolling it out in a phased approach, specifically starting with pipelines operating at lower stress limits, is the best route to begin implementing this, and then progressively as we can make better decisions on pipelines it might be applicable to.”

Cost savings

To “truly display the benefits in tangible terms” of replacing hydrostatic testing, Abate and his team looked at a case study of a “typical pipeline” project segment — a 30-inch diameter natural gas transmission line that totals 32 kilometres in length (about 20 miles). A project like this has a US$7.6-million-per-mile average cost, which totals $153 million.

He said: “Looking at the project aspects that would be eliminated, we could save a significant volume of water and no truckloads with the corresponding costs. Additionally, there’d be a 14-day schedule improvement, which equates to $2.1 million in avoided labour costs.

“As mentioned, water remediation is not a requirement to all projects, but it does have a significant cost when required. Overall, $3.8 to $6.3 million can be saved, equating to 2.5 to 4.1 per cent of the total installation cost.”

Stakeholders onside

Stakeholder engagement is a key part to successfully replacing the hydrostatic test, noted Alanna Komisar, energy solutions advisor with Enbridge. Ensuring changes are implemented in partnership with stakeholders, even including voices from environmental groups, should help “smooth in these kinds of transitions” for the sector.

“In the past, individual projects have been greenlit to forgo the hydro test as an exemption,” she said. “But if we want to scale our environmental cost savings and see the benefits for more new pipeline projects, then the opportunity really hinges on our ability to collaborate in early stages of sourcing and construction across the organization and job functions.

“This is about bringing in our friends from construction engineering, codes and standards, procurement, policy, environmental activism, and, of course, our workers on the ground.”