Edit ModuleShow Tags
Edit ModuleShow Tags

Repsol Q2 Pad Gas and Mud Release SITREP # 20


Division of Spill Prevention and Response
Prevention and Emergency Response Program


Repsol Q2 Pad Gas and Mud Release

SPILL NUMBER: 12399904601

TIME/DATE OF SPILL: Repsol reported the incident to ADEC at 10:29 a.m. on February 15, 2012.

TIME/DATE OF SITUATION REPORT: 3:30 p.m. on March 6, 2012

TYPE/AMOUNT OF PRODUCT SPILLED: Repsol estimates that approximately 42,000 gallons (1,000 barrels) of fresh-water-based drilling mud have been released to the ice drilling pad and adjacent snow-covered tundra. An unknown amount of gas has been released. Drilling mud is used to lubricate the drill, control formation pressure, and remove cuttings from the bore. No oil was spilled during the release event.

INCIDENT LOCATION: Qugruk #2 pad (Q2 pad), on the Colville River Delta, approximately 18 miles northeast of Nuiqsut and approximately 150 miles southeast of Barrow (70° 27’ 19” N, 150° 44’ 52” W).

CAUSE OF SPILL: Repsol contractor Nabors Drilling was drilling an exploratory well when the drill penetrated a shallow gas pocket at a depth of 2,523 feet, resulting in a gas kick. The gas kick drove drilling mud out of the well and through the gas diverter onto the ice pad and adjacent snow-covered tundra. The gas diverter is a pipe that extends approximately 75 feet from the drilling rig toward the south edge of the pad. Additional mud was pumped into the well in an attempt to control it, but that mud was also forced out by the gas.


RESPONSE ACTION: The primary actions being taken now continue to be work towards successful well control.

A coiled tubing unit and crane are on site and is being rigged to clean out the blockage. The first step is to pump a heavy mud into the well annulus (the space between the drill pipe and the formation) to stabilize it. With the annulus stabilized, Repsol will run the coil tube down the drill stem and attempt to melt and wash out the obstruction. Once the coil tube has cleared the obstruction and the coiled tubing crew get down towards the foot near the drill bit, they will start pumping in a heavy completion fluid. If the coiled tubing effort is successful and the blockage is cleared, Repsol will evaluate the condition of the well and work to finalize the well-kill plan.

Since the previous Sitrep (19), Repsol reports that 58 barrels (2,436 gallons) of liquids (thawed drilling mud and water) were shipped offsite for disposal, bringing the total to 1,858 barrels (78,036 gallons) of liquids that have been manifested and shipped offsite. Much of the liquid collected is condensed water from the steam used to thaw and clean the rig. Another 569 cubic yards of solid waste (frozen drilling mud) were manifested and shipped offsite, bringing the total to 1,411 cubic yards of solid waste that have been manifested and shipped offsite.

SOURCE CONTROL: The well ceased flowing at about 9:00 p.m. on February 16. Preparations for the well-control operation are ongoing.

RESOURCES AFFECTED: Snow-covered tundra and ice pad. Drilling mud can affect tundra plants by changing soil pH and salinity. Brackish water produced by the well may also increase soil salinity.

FUTURE PLANS AND RECOMMENDATIONS: Cleanup cannot safely begin until the well is under control. The well-control team will provide cleanup personnel approximately 24-hours notice in advance of completion of the well-control operation. Plans are in place for sampling the drill mud, delineating and cleaning up the spill and mobilization of necessary personnel crews and equipment. The ADEC incident management team will continue to monitor the operation and two ADEC responders will remain at Palm Pad until cleanup operations are imminent, at which time additional staff will be recalled to both the Anchorage ICP and the site.

Incident Commander: Jeremy Michels, O’Brien’s Response Management
S.O.S.C.: Tom DeRuyter, ADEC
F.O.S.C.: Matt Carr, EPA
L.O.S.C.: Gordon Brower, North Slope Borough
Field SOSC: John Engles, ADEC

WEATHER: Today: Mostly sunny. Patchy ice fog in the morning. Highs around 26 below. Light winds becoming west around 10 mph.
Tomorrow: Mostly cloudy. Patchy ice fog in the morning. Highs 19 below to 25 below zero. Southwest winds around 15 mph.

TIME/DATE OF THE NEXT SITUATION REPORT: As the situation warrants.

FOR ADDITIONAL INFORMATION CONTACT: Ty Keltner, Public Information Officer, ADEC (907) 465-5009

Photographs and other spill information will be available for viewing at: http://www.state.ak.us/dec/spar/perp/index.htm

Edit Module

Add your comment: