UNOCAL Platform Anna; Granite Point oil field in Upper Cook Inlet, Alaska

Granite Point oil field in Upper Cook Inlet, Alaska | 1994-Nov-18

Initial Notification: While conducting drilling operations, UNOCAL platform Anna pumped drill mud through an open valve into a skim tank. The tank overflowed onto the deck and into the platform deck drains, filling the deck drain tank with mud, displacing the water and oil. Approximately 125 barrels of mud were pumped into the half-full tank and about 60 barrels of a water and mud mixture, containing an estimated 15 barrels of crude oil, spilled into Cook Inlet. Cook Inlet Spill Prevention and Response Inc. (CISPRI) deployed its offshore recovery vessel, the Banda Seahorse, to the area. Cleanup and oil sightings were hampered by darkness; the release into Cook Inlet occurred at about midnight. An overflight at mid-morning sighted an intermittent dissipating silvery sheen approximately 4 miles long by 20 yards wide. UNOCAL activated an ICS at the CISPRI command center in Nikiski. The oil naturally dispersed and diluted by noon with no observable shoreline impact. Throughout the incident the weather was clear and winds were northeast 10 to 20 knots, producing choppy seas. USCG district 17. Keyword: none.