Repsol's effort with Slope well delayed by blockage
Repsol E&P USA has encountered a new problem, a blockage in the well bore of its Qugruk No. 2 exploration well on the North Slope, which has delayed attempts to bring the well under control.
Repsol encountered a shallow gas pocket Feb. 15, which resulted in a gas blowout and evacuation of the rig. The well is on the Colville River delta, west of the producing Prudhoe Bay and Kuparuk River fields.
In a situation report issued March 3, the Alaska Department of Environmental Conservation and drilling contractor Nabors Alaska Drilling was using a special tool to survey the well for damage and discovered a blockage of some type in the well pipe.
“A coiled tubing unit and crane have been contracted to clean out the drill pipe but the temperature must be above minus 35 degrees F. for them to operate,” the agency said in a statement.
Ambient temperatures at the well were at minus 44 degrees F. with a wind chill of minus 68 degrees over the weekend.
The weather forecast is for a gradual warming and for temperatures to reach above minus 35 degrees by March 6, the agency said.
Once the coiled-tubing unit is on location and the well is cleaned out, a second wireline log will be run to assess the condition of the well pipe and a well-kill plan will be finalized, the ADEC statement said.
The flow of gas from the well ended the evening of Feb. 16, about 40 hours after the blowout was experienced, with an estimated 42,000 gallons, or 1,000 barrels, of water-based drilling fluids ejected from the wellbore.
No injuries resulted but the evacuation of the rig. The freezing of drill fluid on the rig, the possibility that some methane may be seeping from the open well, plus extreme cold temperatures have slowed the recovery operation.
Cleaning and drying of the rig’s power components have been completed, however, and the rig is operational.
The well will be considered back under control when the drilling crew is able to pump drill fluids down the pipe, according to Cathy Foerster, Commissioner on the Alaska Oil and Gas Conservation Commission.