Three Offshore Oil Platforms to Shut Down

The three oil platforms off Point Arguello up by Vandenberg Air Force Base may soon have their 62 wells plugged and the casings pulled up and out of the water. The project, proposed by Freeport-McMoRan, which owns the three platforms — Hidalgo, Harvest, and Hermosa — is to be scheduled as the platforms have reached the end of their economic life, the environmental assessment released in January states. Bureau of Ocean Energy Management (BOEM) spokesperson John Romero stated Freeport had not yet applied for a permit to decommission, or remove, the platforms themselves.

Located in federal waters six miles offshore in depths of 500-600 feet, the platforms were planted in 1985 and went into production in 1991. The well closures are expected to begin before March 2020 and take 208 days. After the wells are plugged, the well conductors — the pipes that move the oil from the well below the sea floor to the platform — are to be cut 15 feet below the sea floor, with the sonic percussions from the grinding cuts expected to travel and affect marine mammals less than 50 meters away. As the casings are pulled up, they will be cut to fit onto the Harvey Challenger and taken away during the ship’s regularly scheduled trips to and from the platforms. The ships are limited to 10 knots of travel to avoid mammal strikes and take the well casings to San Pedro Harbor for disposal.

As well as noise and ship travel, the environmental assessment looks at spill prevention, produced grinding materials, emissions, and other impacts to the surrounding sea life from the project. The report notes that shellfish, like mussels, were routinely removed from the platform legs to avoid damage to the platform; they formed heaps of shell middens on the sea floor that have become home to small or young fish.

The “Point Arguello Unit Well Conductor Removal” environmental-review documents were released by the Bureau of Safety and Environmental Enforcement (BSEE) and the BOEM, and they are available at boem.gov. A 15-day public comment period began ticking on January 31, and comments are due before midnight on February 14.