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CIPC shuts in Drift River terminal Explosive event at Mount Redoubt triggers change in strategy and forces Chevron to shut in oil production at 10 offshore platforms; producers studying other ways to move oil Alan Bailey Petroleum News
The unified command for the response to the threat to the Drift River Marine Terminal from the eruption of Redoubt Volcano breathed a collective sigh of relief at 1 p.m. April 6, following the successful offloading of 3.7 million gallons of crude oil from the terminal tank farm into the tanker Seabulk Arctic, moored at the Christy Lee platform, the terminal’s offshore loading dock on the west side of Alaska’s Cook Inlet.
After offloading the oil, the tanker had used its onboard pumps to inject 840,000 gallons of Cook Inlet seawater back into the terminal tanks, to prevent the tanks becoming buoyant, were eruption-induced floodwaters from the nearby Drift River to inundate the terminal.
And following the placement of the water in the tanks, terminal owner Cook Inlet Pipe Line Co. proceeded to shut-in the terminal, draining potable water from the terminal facilities, protecting buildings with sandbags and using onsite heavy equipment to build berms to protect the road to the terminal’s airstrip.
All personnel were subsequently evacuated from the terminal.
“The Cook Inlet Pipe Line Co. will continue to evaluate the volcano and its activity. I want to make sure that everybody understands that we are concerned about our personnel on site,” said Rod Ficken of CIPL, during an April 6 press conference, while the terminal shutdown was in progress.
And, with its task accomplished, the Seabulk Arctic transited to the east side of Cook Inlet, to deliver its cargo of oil to Tesoro’s Nikiski refinery on the Kenai Peninsula.
6 million gallons On March 29, faced with mudflows lapping at the protective dike around the tank farm and with about 6 million gallons of crude oil in the farm’s two active tanks, the U.S. Coast Guard, the Alaska Department of Environmental Conservation and CIPC formed a unified command to address the situation that had evolved since Redoubt started erupting on March 22.
U.S. Coast Guard Captain Mark Hamilton became federal on-scene coordinator, after an initial stint by USCG Commander Joseph Lo Sciuto in that position. Gary Folley from ADEC represented the state in the unified command, while Rod Ficken represented CIPC.
The unified command’s initial strategy was to offload oil from the tank farm, leaving just enough oil in the tanks to prevent the tanks becoming buoyant while also retaining the possibility of moving oil from the west Cook Inlet oil production facilities at Granite Point and Trading Bay, should conditions permit. The Cook Inlet oil pipeline that runs down the west side of the inlet connects those processing facilities to the Drift River terminal. But, with the shutdown of both the pipeline and the terminal after Redoubt started erupting, the oil producers had been stockpiling oil in storage tanks at the production facilities as a means of keeping production going from the offshore oil fields on the west side of the Inlet.
So the unified team arranged with Tesoro to have the Seabulk Arctic arrive at Drift River on April 4 to carry out the offloading operation. The team hoped that, in addition to lowering the oil level in the Drift River tanks, the tanker would be able to drain some oil through the Cook Inlet pipeline from the tanks at Granite Point and Trading Bay, to prevent those tanks from filling up and, thus, cause production from the oil fields to cease.
Strategy rethink But a massive Redoubt explosion and an accompanying flood of mud-laden water down the Drift River early in the morning of April 4 prevented the tanker from docking as planned and caused a major rethink by the unified command.
In a new strategy, recognizing the imperative of safety and environmental protection following the April 4 explosion, the unified command decided to remove as much oil as possible from the terminal, using seawater rather than oil to ballast the tanks, abandoning the attempt to drain down the tanks at the production facilities and suspending all operations at the terminal for the foreseeable future.
And at 7 p.m. on April 5 the Seabulk Arctic duly arrived at the Christy Lee platform to carry out the required oil loading and water pumping, completing these operations by the afternoon of April 6.
Meantime, with the Granite Point and Trading Bay storage tanks filling with oil, the Cook Inlet oil producers had to shut-in all of the production wells on the west side of Cook Inlet. Chevron, which had already had to suspend production from two of its offshore platforms and reduce production at a third platform as a consequence of the Redoubt eruption, shut-in all of its remaining production on April 5.
Chevron spokeswoman Roxanne Sinz told Petroleum News April 6 that the shut-in had resulted in a loss of 7,500 barrels per day of oil production but that the production of natural gas from the west side of Cook Inlet had not been impacted.
“We’re still evaluating what impact this will have on our employees and future operations,” Sinz said.
Known threat The threat to the Drift River terminal posed by the Redoubt Volcano became apparent during the eruption of 1989 and 1990, when mudflows down the Drift River diverted the river flow from the north side of the terminal to the south side and caused minor flooding in the tank farm — the Drift River flows out of the Drift Glacier on the rim of Redoubt’s crater, so that eruption-induced melting of the glacier can cause flood water to pour down the river valley.
In 1990 CIPL built a massive dike system to protect the tank farm in the event of another eruption. And that award-winning engineering project appears to have paid off — neither of the flooding events during the current eruption has penetrated the dike defenses and the dike structures, protected from erosion by cement, appear to have held strong.
Also following the previous Redoubt eruption, CIPL repositioned the Cook Inlet pipeline river crossing at Drift River, using a horizontal directional drilling technique to place the pipeline deep under the river bed, to avoid damage from blocks of ice or rock carried down the river. And pressure monitoring of the pipeline during the current eruption indicates that the pipeline has remained intact.
On April 8 ADEC Commissioner Larry Hartig explained why, when the Seabulk Arctic drained the oil from the Drift River tanks, the response team had been forced to leave more than 2 million gallons of oil in the tanks, despite the fact that the team had used seawater to reduce the tank buoyancy.
Essentially, the outlet pipes from the tanks are located about two-and-a-half feet up the tank walls, to allow space for sediment to collect in the tank bottoms, Hartig said.
“You couldn’t pump down into that sediment because … once you get down to the level of that pipe … you just can’t pump further,” Hartig said. Besides which, attempting to pump the sediment would foul the pumps and piping, he said. Although the sediment is cleaned from the bottoms of the tanks about every 10 years, mounting this type of cleaning operation, an operation that takes several weeks to complete, requires the opening of the tanks and involves handling hazardous materials, which would have posed unacceptable safety risks during the period that Mount Redoubt is erupting, Hartig said.
Tom Irwin, commissioner of the Alaska Department of Natural Resources, commended the various people and organizations involved in the response at Drift River.
“You can really tell the good people in hard times,” Irwin said. “… The response worked as it was supposed to. And good people did come together and they responded correctly in this unified command.”
But what of the future? At this point it is not clear how long the Drift River terminal will remain closed, or even if there will prove to be some other viable way of shipping oil from the west side of Cook Inlet.
“As we understand it the owners … have an engineering team looking at other options to transfer the oil,” Hartig said. “We do not know at this time whether the Drift River facility will be opened again, or whether some alternative will be found to it.”
And any reopening of the facility would require a re-evaluation of the facility’s oil spill contingency plan, including a review of the risk factors identified in the plan, Hartig said.
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