The Lena, a former Exxon Mobil oil rig, is located 50 miles southeast of Grand Isle, Louisiana. The company towed away from the above-water platform after the site began extracting crude. It finished the job in July by disconnecting the structure from the seafloor and toppling it over. It's now a man-made reef.

That's the rule in the United States: when an offshore oil well produces its final barrels, producers must be ready to seal it, uninstall the platform, and return the ocean floor to its original state. If it’s left standing, the rig may pose a threat during hurricanes, prevent future oil exploration, and, in some cases, obstruct wind-power production.

A rig is more than just metal and concrete. The framework becomes home to coral, mussels, and a variety of other marine life over the course of its life. There could be an existing ecosystem down there by the time a company's lease expires.

Around 1,700 rigs in the Gulf of Mexico will have to be dismantled at some stage. They're known as "idle iron" as a group. Since the 1980s, 560 US platforms in the Gulf have been left underwater and transformed into permanent artificial reefs.

Programs like "Rigs to Reefs" make coral, shellfish, fish, and fishing boats happy. Reefing is also less expensive for oil companies: it costs only half as much as a complete decommissioning. Companies donate half of their cost savings to states that assume responsibility for the artificial reefs.

Environmentalists, on the other hand, argue that converting rigs into reefs falls short of the promise companies made when they signed the lease, to begin with. "Nobody would believe the quantity of junk that would be lying around out there if you could pump all the water out of the Gulf of Mexico right now," said Richard Charter, a senior fellow at the Ocean Foundation.

Exxon Mobil tried out an artificial reef for the first time in 1979 but refused to comment for this on this report. The states with a large number of reefing programs are Louisiana and Texas, while Mississippi and California also have programs. According to an overview, Louisiana has received $100 million as a result of this agreement since 1986. Louisiana earned nearly $562,000 per rig between 2012 and 2018.

Texas has already converted at least half of its available rigs, while Louisiana has only converted a third of its potential space. Because of the structural transformation of the oil industry, these states "should begin preparing for a future where the income produced from future projects finishes," the authors of a report confirm.

Decommissioning an offshore project is a massive undertaking. Years of preparation are needed through various federal and state departments, as well as the organization itself. The Lena Compliant Tower, designed by Exxon Mobil, weighed 27,000 tonnes. The entire facility was 50 feet taller than the Empire State Building.

There are three methods for converting a rig to a reef. It can be towed to a specified reef area in the Gulf. If it's 85 feet below the surface, it can be left alone. It can also be "destroyed," as in the case of Lena. According to the US Bureau of Safety and Environmental Enforcement, unmooring a rig's structure and safely pushing it over will damage some existing coral life, but won’t damage the ecosystem.