Wherever an oil and gas platform is installed, most governments require complete removal and site cleanup when production is terminated. In the United States the time is one year in most cases. This can happen when production is no longer economically viable or the lease is terminated for other reasons.
Some bottom-sitting platforms can be repurposed as artificial reefs. This is the “Rigs to Reefs” program. It enhances the immediate marine environment and offers considerable savings in decommissioning costs. The decks where the machinery is located are taken ashore for scrapping. The legs that support the decks are relatively clean. They can be cut off, tipped onto the seafloor, or removed for towing to another reef site.
Water clearance between the sunken legs and the surface has to be great enough to not interfere with shipping traffic. In U.S. waters the Coast Guard requires an 85-foot clearance between the reef top and the surface. This means that the candidate platforms must be sited in at least 100 feet of water. Cutting can be done by divers using mechanical tools or cutting torches, or remotely by explosives.
The Gulf of Mexico was where the world’s first offshore platform was installed in 1947. Since then more than 7,000 have followed. The Rigs to Reefs initiative began there in the mid-1980s. While today less than 3,000 remain, this is still the greatest concentration of rigs in the entire world—in fact, a greater number than all other offshore platforms on the planet.
Between the end of 2012 and the end of 2013, some 350 platforms were scheduled for removal. However, “reefing” will be approved for only 12 percent of them. While this seems like a small number, the absolute numbers since program inception are impressive. The total number of platforms reefed today is a bit over 438, or about 10 percent of all removals in the Gulf. Louisiana is first with 320 reefs, Texas has 103, Mississippi 8, Alabama 4, and Florida 3.
Due to environmental and habitat concerns with the coastal ocean, many federal and state agencies have a stake in this program. The lead federal entity is the Department of the Interior through its Bureau of Ocean Energy Management and Bureau of Safety and Environmental Enforcement. Yet it all seems to work, and the reefs are being created. Perhaps this is because these agencies have been doing this for nearly three decades. Now offshore regulatory agencies in other parts of the world see the U.S. Gulf of Mexico experience as a useful model.
Why are these reefs important? For the platform owner it costs much more to remove platforms than their scrap value can produce. Decommissioning can represent a major cost for the oil companies. Leaving part of the platform in place can result in significant savings.
Oil platforms are de facto reefs. An eight-leg jacket offers about four acres of surface area for attached organisms, and the population of fish will be in the order of 15,000–20,000. Density of fish around a platform has been found to be 20 to 50 times greater than in the nearby open ocean.
This was learned a half-century ago when sport fishermen would get their best catches in the immediate vicinity of platforms. Initially the rig operators did not welcome them around their platforms. But they soon learned that accommodating sport fishermen, sport divers and charter-boat operators was a great “goodwill” activity.
Because existing platforms are such rich habitats, their removal leaves a hole in the local ecosystem. Some environmentalists wanted all rigs to be left standing. So it was in the government’s interest to maintain that biome without the structures being left in place.
To create a reef, the rig operator submits to state and federal authorities a decommissioning plan for use of the jacket as an artificial reef. If the appropriate government agencies agree to the removal plan, then the state will take ownership of the jacket once it is at the reef site. For their part, platform owners are required to hand over 50 percent of their cost savings to the state as an endowment for maintaining the new reef. Savings are calculated from what it would have cost to move the entire platform ashore for conventional scrapping.
Rigs to Reefs may be one of the few areas where petroleum companies and conservationists both agree on the benefits. It is very much a win-win situation for the operator, the state, sport fishermen, divers—and, of course, the fish.