Day 4 of the trans-Alaska oil pipeline shutdown:
The biggest oil-field operator on the North Slope was preparing to pump oil back into the ground.
Environmental officials were supporting a plan that allows some more oil to leak in order to prevent bigger problems.
And a whirlwind of activity was under way to make repairs and get oil pulsing through the pipeline again.
As temperatures dropped at Prudhoe Bay and the shutdown of the 800-mile pipeline continued Tuesday, federal and state regulators agreed to allow Alyeska Pipeline Service Co. to temporarily restart the flow of oil even though some will ooze out of a leaking secondary pipe.
The flow of oil back into the pipeline was to resume Tuesday night, said Alyeska spokeswoman Michelle Egan.
That was expected to raise the temperature of oil in pipelines and tanks, avoid a more complex cold restart, avoid expected problems with freezing and wax buildup and allow North Slope operators to resume higher levels of production, Alyeska said.
"We are in the middle of the restart process. We are opening valves," Egan said around 8:30 p.m. The pipeline was shut down for more than 80 hours, the second-longest period in the pipeline's 33-year history.
STORAGE TANKS FILLING
Alyeska, which operates the pipeline that delivers oil from the North Slope to Valdez, has been grappling with a dead-of-winter shutdown since Saturday.
Risks of freezing pipelines and equipment increase the longer the flow is cut off, federal and state officials say. The shutdown has cost the state of Alaska more than $18 million a day in oil royalties and taxes.
Alyeska cut off the flow of crude to the pipeline just before 9 a.m. Saturday after workers discovered oil leaking from a pipe into the basement of a pump building at Pump Station 1 near Prudhoe Bay.
Oil field operators were directed to cut production to 5 percent of normal, or about 30,000 barrels a day. The limited amount of oil has been stored in two holding tanks at the pump station.
But the two tanks, which together hold only two-thirds of the 630,000 barrels produced on a normal day, were filling up. They'd be at capacity before the damaged area could be sealed off and a new 157-foot bypass line is built, according to the state Department of Environmental Conservation. Just fabricating the new piping in Fairbanks is expected to take several more days, DEC said.
If the tanks reached their capacity, all North Slope production would have to be shut down, risking cold weather damage to wells and pipes, as well as the trans-Alaska pipeline itself, according to DEC.
As of Tuesday, the temperature of oil in the pipeline was 32 degrees in places and expected to drop a couple of degrees a day.
Asked whether water in the lines already was freezing, Egan said, "I think trying to restart today was to avoid that."
RISKS OF A RESTART
So far, 48 barrels or 2,000 gallons of oil has been recovered from the pump building.
The temporary restart will pump oil through damaged underground piping connected to the building, which may cause more leaking in the building, according to the state and federal regulators. So far no oil has been seen on the ground, but with the restart it could spill out of the building onto the soil, the DEC said.
"These kind of things -- especially in these kind of conditions -- there is never anything but difficult decisions," said Mark MacIntyre, a spokesman for the U.S. Environmental Protection Agency working in the command center. "This just happens to be one where we feel like moving forward with that plan will help ultimately address the situation here and get everything back to normal sooner than anything else."
About 450 people -- including more than 400 Alyeska employees and contractors -- are working on the spill, repairs and pipeline restart. About 200 of them are stationed at Pump Station 1.
Alyeska installed an 800-gallon containment tank where the oil has been seeping, and oil can be removed from it with vacuum trucks. Crews will monitor wells and the ground for signs of oil.
Spill response crews from Stevens Village, Rampart and Alyeska's Ship Escort Response Vessel System are stationed in Fairbanks to be ready in case any new spills occur unexpectedly along the main pipeline during restart.
During the shutdown, two cleaning devices called pigs were in the trans-Alaska pipeline, and one of them escalated concerns about ice and wax buildup. The pig at issue was near Fairbanks between miles 419 and 420 near Wickersham Dome, north of Pump Station 8. Officials were concerned it would cause problems if left in the pipeline too long during cold weather.
Once oil begins to move again, the flow will move the pig. Crews at Pump Station 8 are supposed to trap the pig between two valves.
PUMPING OIL DOWN WELLS
On Tuesday afternoon, BP Exploration (Alaska) Inc., the biggest North Slope operator, received permission from the state to pull oil out of some wells and inject it into others. The activity protects oil field equipment and lines from damage due to freezing, the Alaska Oil and Gas Conservation Commission said in its emergency order.
"If they can't put production into the pipeline, then they just got to slosh it back and forth between the wells," said Cathy Foerster, one of the three oil and gas commissioners responsible for ensuring the resource isn't wasted and that wells are operated safely.
With the pipeline restarting, oil field operators will be able to ramp up production, though not up to their normal levels, Egan said. It wasn't clear if BP still intended to channel oil back into the ground. Steve Rinehart, a BP spokesman, earlier in the day declined to answer questions on how BP was dealing with the situation.
It takes a while for operators to change production levels, and they'll have to curtail production again late this week or early next week when the repairs are being done and the pipeline shuts down again. Sealing off the damaged area and installing a bypass pipeline is expected to take 36 hours, once all the materials are in place, DEC said.
Find Lisa Demer online at adn.com/contact/ldemer or call 257-4390.
By LISA DEMER
ldemer@adn.com