While most of California’s 27 offshore oil platforms are expected to be shuttered by 2055, and several have already been closed for good, there’s a looming quandary of what to do with the massive structures themselves once they’re out of commission.

Numerous obstacles stand in the way of taking them apart and hauling them to shore. There’s no clear process for dismantling them and, with some the size of the Empire State Building, the total cost could exceed $2 billion.

What’s more, complete removal would also eliminate the rich marine habitat that has developed around their underwater bases. And while it comes with its own significant hurdles, there’s a growing push to tip the wells over once they are plugged up in order to preserve and expand the artificial reef ecosystem.

That approach, endorsed by state legislation in 2010, would save oil companies money, put more than a half billion dollars in state coffers and possibly turn the environmentally risky platforms into hubs of ecotourism.

“All the (California) platforms having booming ecosystems underwater,” marine scientist Amber Sparks said at an Aquarium of the Pacific lecture in Long Beach on Wednesday, March 2.

“There’s a lot of real estate; a lot of nooks and crannies for marine life,” she said. “Scientists at the National Academy for the Sciences have found California’s platforms are some of the most productive marine habitat in the world.”

Sparks is co-president of the San Diego-based Blue Latitudes Foundation, a non-profit whose mission is to engage industry and government with ocean conservation efforts.

“Rigs-to-reefs is a perfect example of that,” she said.

Uncharted waters

The Gulf of Mexico is the poster child for rigs-to-reefs, with more than 500 decommissioned oil platforms turned into full-time artificial reefs over the past 30 years. It’s bold testament to the habitat potential of the rigs, transforming the relatively sterile, sandy bottom ecosystem there into one with hundreds of prime locations for marine life.

But to find something similar, Californians needn’t look beyond their own existing offshore rigs, the largest of which provide several distinct ecosystems throughout the depth of the platform base. The deepest reach 1,200 feet below the surface.

In shallow waters, strawberry anemone are common. A bit farther down, sea lions feed on small fish — and use the structure as a resting place. More than 79 species of fish are found in the midwaters of the platforms, according to a Blue Latitudes graphic.

Farther down, rockfish and other overfished species are able to reach maturity in greater numbers than they currently can at natural reefs. And on the sea floor, mounds of shells fallen from rock scallops and mussels serve as a nursery for juvenile fish.

A 2010 law signed by Gov. Arnold Schwarzenegger, AB 2503, provided a legislative path for turning platforms into full-time reefs, a process that typically involves tipping the structures on their sides or lopping off the top-most parts to relocate them on the sea floor. The resulting artificial reefs must be at least 85 feet beneath the surface to allow adequate clearance for ocean vessels.

Two of the issues standing in the way of implementation are the absence of start-up funding and liability responsibility, which would fall either to the state or the platform owner.

“None of the parties are stepping up to assume that liability,” Sparks said.

At least not yet.

Big incentives

California’s aging platforms aren’t quite ready to dismantle or tip over, but the time is rapidly approaching. There are 27 platforms in state and federal waters, 16 of which are not currently operating, including three that have been temporarily shut down because of last October’s oil leak in Huntington Beach.

At least eight of those platforms are not expected to reopen and have begun — or will soon begin — the decommissioning process, which includes plugging the wells and dealing with the structures themselves, according to John B. Smith, an offshore oil consultant who previously worked with the Washington, D.C., agency that oversees oil leases in federal waters.

Beside the age of the platforms, their lifespan is nearing the end because offshore oil production in California is declining. In 1995, the most recent peak, platforms in federal waters were producing 72 million barrels a year. But by 2019, annual production was down to just 4.5 million barrels, according to Smith’s analysis of federal data.

“The main reason is that most reservoirs are depleted, especially for the older facilities,” he said.

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It’s been more than 25 years since a platform was last dismantled in the state and there is no equipment or other infrastructure here to take them apart, haul them to shore and recycle or otherwise dispose of the massive remains. There’s also little precedent for removing rigs as large of those in California waters, where the biggest weighs 86,000 tons.

But there are incentives for both platform owners and the state to pursue rigs-to-reefs rather than hauling the structures to shore. Removing the 23 platforms in federal waters would run $1.6 billion, according to federal estimates — and Smith said the price could end up being twice that.

Transforming the structures into reefs could cut the cost in half, saving the owners money. And the 2010 law calls for 65% to 85% of that savings to be paid to the state, amounting to an estimate $650 million to $850 million, Sparks said.