Hibernia Management and Development Company Ltd. (HMDC) has pleaded guilty to one charge of “failing to cease work causing pollution” related to the July 2019 spill that released about 75 bbl of a crude oil and water mix into the Atlantic Ocean.

HMDC announced on July 31 that other charges related to the incident against HMDC have been withdrawn and that the company has taken action to address lessons learned from the incident.

Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB) announced on Aug. 1 that a CA$90,000 fine had been imposed under the Canada-Newfoundland Atlantic Accord Implementation Act (Accord Act), and that HMDC has been ordered to pay CA$310,000 into the Environmental Damages Fund.

Exxon Mobil holds 33.125% interest in HMDC, Chevron Corp. holds 26.875%, Suncor Energy holds 20%, Canada Hibernia Holding Corp. holds 8.5%, Murphy Oil holds 6.5% and Equinor Canada Ltd. holds 5% interest.

The Hibernia gravity-based structure is in about 80 m water depth and can store 1.3 MMbbl of crude oil in storage cells before the hydrocarbons are offloaded to a tanker. The storage cells hold oil, topped by water, and its crude oil interface level measurement system (COILMS) tracks the oil-water interface. During normal operations, produced crude displaces seawater through the ballast water system, and that water is discharged into the Atlantic Ocean.

According to the agreed statement of facts, on July 17, 2019, “Notwithstanding that COILMS indicated that the interface level and the thickness of the interface layer were as expected in Cell Group 3, a portion of the crude oil and water interface layer was unexpectedly discharged into the ocean via the deballast system.”

Timeline of events

The agreed statement of facts provides this timeline:

An alarm sounded at 12:48 a.m. NL Standard Time when the oil-in-water analyzer detected 15 parts per million crude oil concentration in the discharge water.

At 12:53 a.m. NL Standard Time, the ballast water tank high level alarm activated, indicating the level of the ballast water tank was trending toward, but had not reached, an upper limit. The deballast water discharge oil-in-water analyzer alarmed intermittently until 4:42 a.m., and intermittently from 1:37 p.m through 2:06 p.m.

At 12:56 a.m. the operations technician switched production out of Cell Group 3, which stopped the displacement of fluid from Cell Group 3 into the deballast water system. Other technicians began to investigate the cause of the oil-in-water analyzer alarm, including by inspection, testing and re-calibration of the equipment. Some of Cell Group 3’s interface layer’s crude oil and water mixture had already mixed with the contents of the ballast water tank.

At 6:52 a.m., the Avalon Sea, a stand-by vessel, reported oil on the ocean surface, and HMDC initiated its oil spill response and investigation of the source of the sheen. Those activities included standing up its incident management team, aerial surveillance, deploying oil spill response equipment and resources, sheen monitoring and wildlife observers and engaging with regulatory authorities.

At 10:38 a.m., HMDC reported the discharge to the C-NLOPB.

At 5:13 p.m., after observing crude oil in the platform’s ballast water tank, a controlled shutdown of the Hibernia Platform began, allowing further troubleshooting activities.

HMDC carried out a full Tier 1 and Tier 2 oil spill response operation, and the cleanup effort lasted two and a half weeks.

Dropped object

In other news, C-NLOPB announced on Aug. 1 that HMDC had reported a dropped object during lifting operations on July 25. While a crane was lifting a chemical tank from the Hibernia Platform to a support vessel, a 1.8 kg piece of timber from the tank support frame fell 15 m to the deck of the vessel. While there were no injuries and no personnel were inside the pre-designated lifting exclusion zones either on the platform or the vessel, the incident had the potential for fatality based on the dropped objects prevention scheme calculator, C-NLOPB said.

HMDC has initiated an investigation into the root cause of the incident, which the C-NLOPB is monitoring.