Oil officials keep eye on high water at Alpine field

The Associated Press

Spring thaw in the Colville River Delta has surrounded the Alpine oil field in floodwater, prompting a suspension of drilling and other steps to keep workers and the environment safe.

Alpine is the third most prolific field on the North Slope. Production of about 100,000 barrels of oil a day has not been interrupted.

Melting and ice jams on the Colville and some channels have caused the highest water levels at Alpine since the field started producing four years ago.

Floodwaters came within 16 inches of the base of the main pipeline at Alpine, according to officials at the Alaska Division of Oil and Gas. The pipeline transports crude oil from Alpine to the Kuparuk field about 34 miles away. Water also came within 14 inches of the lowest point of an access road connecting two drilling pads. The pads sit on gravel about 4 to 6 feet above the ground.

Flooding is a concern at oil fields because pipeline supports can erode out from underneath, destabilizing lines, said Leslie Pearson, a state spill-response manager.

As of the morning of May 28, the water levels appeared to be receding, but city officials at nearby Nuiqsut remained on heightened alert. Mayor Rosemary Ahtuangaruak asked the North Slope Borough to provide a staff person to monitor water levels in the channel nearest town. The water was about 6 feet from topping its bank the last time she checked, Ahtuangaruak said.

“I’d rather be proactive than to wake up and have an ice chunk banging against the house,” Ahtuangaruak said.

Hydrologists for ConocoPhillips Alaska, the company that runs Alpine, are checking gauges and monitoring river conditions daily by helicopter. Microwave communications have been set up in case fiber optics fail due to flooding. A drilling rig was shut down and put in maintenance mode as a precaution, according to an e-mail Conoco sent to government agencies alerting them to the situation.

Conoco spokeswoman Dawn Patience downplayed the severity of the risks.

“We haven’t executed anything operationally different. Everything right now is normal,” Patience said.

The Colville River Delta is a well known flood plain. Environmentalists had opposed the field going forward, in part because of the flood risks.

Precisely because of the topography and conditions, structures at Alpine were built to withstand a 200-year flood, Patience said.