Problems in Alaska? The massive oil pipeline is threatened by permanent freezing

The Trans-Alaska Pipeline, one of the largest oil pipelines in the world, could be in jeopardy.

Permanent freezing melts threatens to damage the supports holding up an elevated part of the pipeline, jeopardizing its structural integrity and increasing the potential for an oil spill in a delicate and remote landscape.

The permanent freezing slope where an 810-meter section of the pipeline is provided has begun to shift as it melts, causing some of the holders holding the pipeline to twist and bend.

This appears to be the first instance that pipeline supports have been damaged by slope creep caused by permanent freeze thawing, data and interviews with officials involved in managing the pipeline occurrence.

In response, the Alaska Department of Natural Resources has approved the use of approximately 100 thermosyphon tubes that absorb heat from the permanent frost to keep the slope frozen in place and to prevent further damage to the pipeline support structure.

The proposed project is integral to the pipeline protection, according to November 2020 analysis departments.

While the use of these pipes is common along the alignment of the pipelines, the available data show that they have never been used before as a defensive protection once a slope has started to slide.

This is a wake-up call, said Carl Weimer, a special projects consultant for him Pipeline Safety Trust, a nonprofit supervisory organization based in Bellingham, Washington. The implications of this speak to the integrity of pipelines and the impact that climate change has on pipeline safety in general.

Permafrost is land that has remained completely frozen for at least two years in a row and is located under nearly 85 percent of Alaska. In recent decades, the permanent freezing temperatures there have warmed to 3.5 degrees Fahrenheit.

The average temperatures of the states are projected to rise 2 to 4 degrees more by the middle of the century, and a study published in the journal Nature Climate Change projects that with every 2 degree increase in temperature, 1.5 million square miles of permanent freezing could be lost in thawing.

Seeking permission in February 2020 to install water heaters on the slope northwest of Fairbanks near the central Dalton Highway Alyeska Pipeline Service Co., which operates the pipeline, confirmed that permanent freezing posed a threat.

The purpose of this project is to protect the integrity of the Trans-Alaska Pipeline (main line) from degradation by permanent freezing, according to enterprise application.

Michelle Egan, a spokeswoman for Alyeska, an association of oil companies that includes a subsidiary of Hilcorp Energy Co., as well as ConocoPhillips and ExxonMobil, declined to comment on the condition of the weakened pipe section or the degree of permanent frost melting.

Egan said the permanent frost changes were anticipated during the original design of the 800-mile pipeline, which opened in 1977 and runs from Prudhoe Bay in the north to Valdez in Prince William Sound in the south.

There are about 124,000 thermosyphons piled up along the pipeline path a nod from its engineers about the importance of keeping the ground beneath it frozen. The pipes are crammed from 15 to 70 feet into permanent freezing in areas where heat can cause it to thaw. But those coolers only cool the permaline directly below the pipeline, which holds the supports.

The new project, in which Alyeska is installing about 100 free water heaters 40 to 60 meters to the ground, is required to maintain a wider slope from collapsing or slipping and damaging the supports.

Construction began last month and is expected to last 120 days and will also include a three-meter layer of insulating pieces of wood on top of the freezer.

To avoid problems with permanent frost, 420 miles of pipeline were built into a raised support system that holds the pipe about 6 feet above the ground. The frames supporting the pipeline, called vertical support members, look like an H-capital with the pipeline supported in cross-stroke.

Tony Strupulis, the pipeline coordinator for the Alaska Department of Natural Resources, said there is no reason to panic that supporting structures are not in immediate danger of collapsing. But he added that the department remains very careful about the implications of permanent freezing thawing for pipeline safety.

The design philosophy is, If it is frozen, keep it frozen, he said.

Trans-Alaskan safety record: 18 oil spills in 20 years

As permanent melting threatens pipeline supports and increases the potential for an oil spill, says Alyeska in emergency response plans that cleaning a spill can speed up melting.

Alyeskas plans to quell permanent frost with extra thermos siphons in the face of global warming as Alaska heats up twice as fast as the global average, underlines an obvious irony: The oil industry must act to maintain permanent freezing to maintain an infrastructure that allows it to extract more fossil fuels that cause heat.

There have been 18 Trans-Alaska pipeline violations in the last 20 years, according to data from the Hazardous Pipeline Materials Safety Administration (PHMSA).

Spills have moved from less than a barrel to 6,800 barrels. In all, the pipeline has spilled 9,784 barrels of oil, resulting in $ 52.7 million in damage and cost, according to PHMSA data.

Causes of spills include corroded pipe failures in equipment failure and operator error. None of the spills recorded by PHMSA are attributed to permanent freezing.

The degree of ecological damage from another spill will depend on the amount of oil spilled, how deeply it has saturated the soil, and whether the dam reaches water sources. But any damage from an oil spill is likely to be greater than in other landscapes due to the fragile nature of Alaska soil and water.

A massive oil spill would be impossible to clean up in the Alaskan environment, said Kristen Monsell, a senior attorney for the Center for Biological Diversity, a non-profit organization focused on protecting wildlife.

Future security efforts should factor in climate change

Federal and Alaska state regulators do not have specific guidelines for addressing safety issues related to permanent freeze thawing. Instead, they rely on general rules requiring pipeline operators to assess stressors, such as earthquakes, vibrations, and thermal expansion and contraction.

While there is no way to make oil transportation safe, regulatory agencies must do everything they can to protect against potential damage, Monsell said.

The Alaska Department of Environmental Conservation said its focus is to ensure operators maintain the integrity of the pipeline by respecting state-mandated inspections that follow industry safety standards.

The pipeline collapse, regardless of the cause, needs to be addressed through a maintenance and inspection program, spokeswoman Laura Achee said in an email. DEC does not have instructions that are specific to permanent freezing.

Richard Kuprewicz, president of Accufacts Inc., a pipeline consulting firm, said it would not be wise for pipeline operators to count on permanent freezing in the same way as in the past.

Assessing pipelines to determine if perennial structural models can withstand changing conditions and the accelerated rate of permanent freezing thawing is prudent, he said.

Operators need to understand this new world that climate change is bringing, he said. What was true in the past may not be true today.

Doug Goering, the appointed dean of the University of Alaska at Fairbanks College of Engineering and Mining, trusts the Trans-Alaska Pipeline for its robust safety design.

However, he said permanent freezing thawing could pose a significant risk to the structural integrity of the pipelines. If permanent melting melts, the earth loses its grip on the pillars, he said. You can understand the consequences.