Drilling
waste, diesel spilled at Conoco OIL field on Alaska’s North Slope
Drilling mud, brine and diesel fuel spilled Monday onto a
gravel pad and into a pit no longer used at the Kuparuk oil field operated by
ConocoPhillips on Alaska’s North Slope, according to the Department of
Environmental Conservation.
The spill happened when a gasket on a steel pipe — what the
industry calls a “hard line” — failed. Water-based drilling fluids were being
sent through the pipe from a processing facility to a disposal well, according
to ConocoPhillips.
Cleanup began Monday and was continuing Tuesday for a spill
initially estimated at 85 barrels, or 3,570 gallons, according to DEC and
ConocoPhillips. The volume will probably end up less than that, said Natalie
Lowman, spokeswoman for ConocoPhillips.
“Any spill we take seriously, and this is no exception,”
Lowman said. “The cleanup effort is very, very rigorous.”
No one was hurt, and oil production is not affected, she
said. The leak was stopped immediately, she said. The pipe is routinely
inspected while in use. ConocoPhillips has contracted with Alaska Clean Seas
for the cleanup.
An area of 3,000 to 4,000 square feet was contaminated,
according to DEC.
The ball mill facility processing the drilling waste was
shut down and the steel pipe was isolated to stop the spill, according to a DEC
report. The failed gasket section was repaired and the line was inspected to
make sure nothing else was leaking, the situation report said.
Besides drilling mud, the spilled materials included salt
water used to clean out pipes and diesel fuel used to prevent freezing in the
line, according to DEC.
Winter cleanups usually go quickly because equipment can be
moved in over the frozen tundra, said Ashley Adamczak, a Fairbanks-based
environmental program specialist with DEC.
“Things freeze in place,” she said. “It’s not spreading any
more.”
The reserve pit was an old receptacle for drilling waste
that had been cleaned up and closed. But now it’s contaminated again and must
be cleaned up, Adamczak said.
Crews are building a snow ramp from the gravel pad into the
reserve pit so that workers can get into the area. The ice in the pit is not
thick enough to support heavy equipment, so crews are using smaller machines
designed to rip up frozen, contaminated gravel, Adamczak said.
Three spill technicians are using Bobcats to work the
cleanup and already have removed 60 cubic yards of material from the gravel
pad, Lowman said early Tuesday afternoon.
A loader was recovering the contaminated material and taking
it to a waste storage area for later disposal, the DEC report said.
Oil companies operating in Alaska have programs in place
that are intended to replace equipment before it fails, but problems can still
occur, Adamczak said.
“It’s just like with your car. You can take it in for
regular inspections, but sometimes in between, something will happen,” she
said.
ConocoPhillips is investigating why the O-ring gasket
failed, Lowman said.