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Drift River Terminal ready for anything Following the Redoubt Volcano eruptions in 1989 and 1990 the oil terminal has bolstered defenses against a natural disaster Alan Bailey Petroleum News
On Jan. 25 the Alaska Volcano Observatory raised the alert level for the Redoubt Volcano on the west side of the Cook Inlet to code orange, indicating the strong possibility of an eruption and triggering concerns about the possibility of a cloud of volcanic ash heading for the population centers on the Kenai Peninsula or around Anchorage.
But, although the seismic activity in the volcano has since subsided somewhat, allowing AVO to reduce the alert level to yellow on March 10, people may be wondering about the level of risk that the volcano poses for the Drift River Marine Terminal, the facility at the foot of the volcano, where oil produced from several Cook Inlet oil fields is loaded onto tankers for transportation to the refinery at Nikiski on the Kenai Peninsula.
Cook Inlet Pipe Line Co., jointly owned by Chevron and Pacific Energy Resources, owns the terminal and the Cook Inlet pipeline that feeds oil into the terminal. Chevron Pipe Line Co., a Chevron subsidiary, operates the terminal on behalf of the owners.
At a distance of some 23 miles from the Redoubt summit, the terminal lies well out of range of any lava or ash flows from the volcano’s crater, Rod Ficken, team leader with Chevron Pipe Line Co., assured Petroleum News on March 10. In fact, ash belching from the volcano’s crater during an eruption tends to be carried into the jet stream, to fall from the sky many miles away — when Redoubt last erupted in 1989-90 no ash or any other kind of material from the volcano landed on the terminal facilities, Ficken said.
Built 41 years ago The Drift River facility was built 41 years ago to support several companies that were producing oil in Cook Inlet, Ficken said. Oil from offshore fields on the western side of the inlet comes ashore into production facilities at Trading Bay and Granite Point, where crude oil is separated from water and any associated natural gas. The oil passes through custody meters into the Cook Inlet pipeline that carries the oil south down the west side of the Inlet to Drift River. The more northerly of the production facilities, the one at Granite Point, lies about 42 miles north of Drift River.
The oil arriving at the Drift River terminal flows into storage tanks. Whenever sufficient oil has accumulated in the tanks, Tesoro, the operator of the Nikiski refinery, schedules a tanker to offload oil from the terminal.
“Tankers come from all over the world and they’ve got to be geared to come into the Cook Inlet,” Ficken said.
The terminal has seven storage tanks, but given the decline in Cook Inlet oil production over the years, only two tanks are currently active, with two other tanks kept operational for standby use.
The terminal is completely self-contained, with its own power generation, for example. Access is by aircraft, using an airstrip adjacent to the facility. An average of 15 people work on site.
And the safety of those people is a paramount concern, Ficken said.
“At Chevron we give people and the environment our top priority,” Ficken said. “… My number one priority in the event of a volcano eruption, or any disaster for that matter, is the folks that work out there.”
Main risk The main risk to the terminal, in the event of Redoubt Volcano erupting, is the melting of the Drift Glacier on the edge of the summit crater at the head of the Drift River. Melting of the glacier can cause a torrent of water and mud to flow down the river, with the potential to inundate some of the terminal structures.
Given that risk, the terminal was built on relatively high ground with dikes around the tanks — the dikes provide containment in the event of tank oil leakage, as well as affording some level of protection from floodwater.
However, when Redoubt last blew in a series of eruptions in 1989-90, a massive flow of water and mud down the Drift River eroded the river banks in some places while also silting up the river, causing the river to divert to the south, to the opposite side of the oil terminal from the normal river channel, and resulting in some flooding in the terminal area.
“(The river) came up against the existing dikes … and they had some water flow into the facility,” Ficken said. “… Our tank farm didn’t get any damage. … We sustained some water and mud within the buildings.”
However, it became immediately clear that flood protection needed to be beefed up.
New flood protection Consequently in 1990 Cook Inlet Pipe Line Co. contracted with engineering company PDC to build a massive two-mile-long dike structure around the Drift River tank farm and to construct some diversionary dikes on the river itself. This major $18 million project, located more than 100 miles from the Alaska road network, involved building a broad, flat-topped embankment, armored with concrete to protect against scouring from a prolonged flood, and more than sized to protect against worst-case flooding events.
Rock for the construction came from a site three to four miles from the terminal, under the terms of a special State of Alaska land lease.
“Then they came and poured all the cement, on site,” Flicken said.
In 1991 the National Society of Professional Engineers named the Drift River Terminal flood protection project as one of nine outstanding U.S. engineering achievements in 1990.
The 1989-90 Redoubt Volcano eruptions revealed another vulnerability at Drift River — the possibility that a large block of ice or rock carried down the river during flood could scour the river bottom and sever the Cook Inlet pipeline at the point where the pipeline passed just 6 feet under the riverbed before reaching the terminal. Although the eruption-triggered flood nearly 20 years ago did not cause a pipeline breach, Cook Inlet Pipe Line Co. contracted with Cruz Construction to move the pipeline to a depth of nearly 60 feet below the river, passing the pipeline through a directionally-drilled, 1,800-foot hole.
That has taken the pipeline to a depth below the level of anything that could come through the riverbed, Flicken said.
Another possibility is that floodwater could float a storage tank off its foundations in the highly unlikely event of a dike breach. To counter this eventuality, Chevron has set minimum volumes of oil that must be present in any tank that contains any hydrocarbons — that minimum oil volume provides sufficient ballast to prevent a tank from floating in water.
“I’ve actually hired an engineering firm here locally to double check our (minimum volume) numbers,” Flicken said. The terminal doesn’t run oil volumes anywhere close either to those minimums or to maximum tank capacity, he said.
Evacuation But, despite all the precautions in place at the terminal, a red alert — an indication that the volcano is about to erupt or has started erupting — would trigger an immediate shutdown and evacuation. Chevron stations one helicopter permanently on site at the terminal and has another on the Kenai Peninsula on 24-hour call, with pilots immediately available, ready to mount an evacuation if necessary. The Kenai helicopter is certified for operation in cloud, Ficken said.
“We go to red, we’re moving everybody out,” Ficken said.
It is possible to shut down field production, production facilities, the Cook Inlet pipeline and the marine terminal all within a few minutes of a red alert. And remotely activated valves on the pipeline would close, isolating different pipeline segments from each other, Ficken said
And in a procedure honed through regular drills, some involving actual shutdowns and some occurring at night when people are in bed, Ficken has established that it typically takes a little more than an hour to complete the shutdown procedure and muster everyone at the landing strip for evacuation. Each person has clearly assigned evacuation duties. The order in which people leave is also specified, so that the people who perform the last tasks are also the last to leave.
And, were there to be a problem with the evacuation, a “safe haven” shelter at the terminal has its own generator plus supplies of fuel, water and food.
Assists AVO The terminal has formed an agreement with the Alaska Volcano Observatory, to assist AVO when its personnel visit Redoubt Volcano to install or maintain monitoring equipment and cameras — AVO maintains a constant vigil over volcano activity, especially during periods of heightened activity such as have been observed recently, activity that has caused AVO to upgrade its Redoubt instrumentation, Ficken said.
“They’ve asked permission to come over and utilize our facility to house their folks and fuel their helicopter,” Flicken said. “… It’s a win-win for the public, for industry and for the AVO.”
The terminal also played host to personnel from the Alaska Department of Fish and Game, when Fish and Game installed new salmon ladders to bypass new waterfalls formed as a result of the last Redoubt Volcano eruption.
But some of the precautions needed when accommodating anyone at Drift River illustrate a unique feature of Alaska wilderness living — dealing with bears.
“We’ve got bears all over the place,” Ficken said. “That’s something we’re concerned about all the time.”
In fact, when someone arrives at the terminal, even the half-mile or so transfer from the airstrip to the terminal living quarters requires transportation.
“In the summer I’ve got to worry about bears,” Ficken said. “… I can’t let (people) walk from the airstrip to the facility.”
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