At approximately 1400 hours ADT on August 6, 2006, Region 10 Phone Duty Officer (PDO) Matt Carr received notification from BP Exploration (Alaska) (BPXA) of a leak from a 30-inch diameter, elevated, crude oil transit line located between Flow Station 1 (FS1) and Flow Station 2 (FS2) within the Eastern Operating Area (EOA) of the Prudhoe Bay oilfield. BPXA reported that 4 to 5 bbls (168 - 210 gallons) of crude oil was released to wet tundra below.
The cause of the leak is under investigation. Data collected from smart pig operations in July 2006, released in a preliminary report obtained on Friday, August 4, 2006, revealed 16 anomalies in 12 locations along this line. These anomalies are associated with corrosion-related pipeline wall thinning. Upon observing oil-stained insulation at one of the anomaly locations (but no active leak), BPXA shut down the FS2 facility that fed this pipeline and closed off the FS2 transit pipeline at the source (FS2) and receiving (FS1) ends. The current leak was discovered on August 6, 2006 shortly after this shutdown, at a location other than the oiled insulation. BPXA has since initiated a voluntary shut down all Prudhoe Bay oil production work due to concerns posed by the current oil leak and related pipeline integrity issues as well as those posed a larger crude oil spill from the nearby GC2 transit pipeline in March, 2006.
Weather conditions are overcast skies with light drizzle and calm winds. Daytime temperature is approximately 50 degrees F.
Upon notification of the discharge, the EPA PDO notified US DOI, US DOT-PSHMA, and the Alaska Department of Environmental Conservation (ADEC). The PDO activated their START contractor and directed them to retain a Historic Properties Specialist to conduct a survey, per National Programmatic Agreement, for the protection of cultural and historic resources. The START contractor was directed to mobilize to spill site and conduct assessment with representatives from ADEC. The OSLTF was opened with a ceiling of $50,000.00 for this incident.
Both START and ADEC representatives arrived in Prudhoe Bay on site Monday, August 7, 2006. They were briefed by BPXA incident management personnel and visited the spill site. BPXA had placed two folding tanks underneath the leaking pipeline soon after it was discovered on August 6, resulting in an estimated loss of approximately 4-5 barrels of crude oil to the tundra underneath and adjacent to the pipeline before the tanks were employed. Response personnel and equipment quickly mobilized to the scene following the discovery, and cleanup work since then has been conducted under 24-hour operations. Also, shore-seal boom was deployed early on August 6 to contain the oil to the immediate area and prevent migration to adjacent water bodies.
The leak of oil from the FS2 transit line is still on-going at this time but the oil is caught in the tanks and then recovered by vacuum truck. Two rope-mop skimmers are in use in the impacted tundra area to remove oil from the marshy surface. Two vacuum trucks are assisting in the recovery operations. The spill impact zone measures an estimated 6,200 square feet. The transit line remains blocked in with a vacuum on each end.
As of 1800 hours today, the leak rate from the line was reported as less than 2 gallons per minute. This is down from what was reported as high as 7 gallons per minute the day prior. Recovery volumes as of the same timeframe are 64 bbls of oil/water mixture recovered from the tundra and 185 bbls of oil recovered from within the folding tanks.
Freeze protection and corrosion inhibition operations are underway to protect oilfield infrastucture during the shutdown.
Fluids removed from the tundra area (oil/water mixture) will be stored separately from crude oil being recovered directly from the pipeline leak.
Further assessment of the transit line to evaluate the corrosion damage is still to be conducted. However, due to concerns over the integrity of the other areas of weakness detected during the smart pig run, BPXA, will be installing patches over the anomaly locations, to be followed by the welding of sleeves over those locations. Folding tanks will also be placed underneath each location as a precaution. Patch installation is planned to begin the night of August 7, 2006, and sleeves are expected to begin arriving in Prudhoe Bay beginning on August 8. The patch and sleeve installations are not intended as permanent pipeline repairs but rather for temporary stabilization as a source control measure.
As a result of the FS2 transit pipeline inspection data and associated oil release, BPXA is in the process of shutting down the Prudhoe Bay oilfield, beginning first with the EOA. The EOA shutdown is expected to be completed within the next 7 days.
START and ADEC representatives will remain in Prudhoe Bay to monitor spill cleanup progress, discuss operational procedures with BPXA response planning and management personnel, and observe site cleanup operations.
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