Offshore oil platforms have a huge presence, physically, financially and ecologically. About 6,000 wells pump oil and natural gas around the world. But since they extract hydrocarbons deep under the sea, these structures pass through the transformation invisible above the waves. The ocean claims that the platforms of huge substructures and turn them into vertical ridge, homes of millions of individual plants and animals.
While the decomposition of the platform is a high task, an increasing number of them have found a new purpose as human ore. Now researchers at UC Santa Barbara have published a comprehensive study of history, ecology and pragmatic efforts on reefs in the journal Ocean and Coastal Management.
In addition to collecting information from a large body of work, scientists hope this study will help inform California residents and policy makers while deciding what to do with retirees platforms from its shores.
"California citizens will have to make decisions to continue the existence of a vast marine life under the platform, and they should be informed decisions," said Ann Scarborough Bull, a researcher at the UC Santa Barbara Institute of Marine Sciences (MSI) and the lead author. This issue will be repeatedly returned around the world as a platform and existing oil fields that reduce production.
For nearly 30 years, Scarborough Bull has been working as an environmental analyst and researcher at the Mineral Management Service at the Ministry of the Interior, now in the Ocean Energy Management Bureau. She joined UC Santa Barbara after retiring as head of the environmental protection agency for the West Bank.
In 2017, the organizers of an industrial summit on the decommissioning of oil wells called Scarborough Bull to talk about the science behind the transition of the platform into permanent reefs. Then she discovered that the literature on this topic is rudimentary and fragmented. After joining the university, Bul decided to collect scattered information in a basic article, to which she added the results of her extensive research.
"As far as we know, paper is the first of its kind," said research biologist Milton Love, also in MSI, who is co-author of the Scarborough Bull study.
There is no doubt that the oil coming from these platforms has a negative impact on the environment. The possibility of devastating oil spill always exists when oil and water mix. Risks can be minimized if the job is done appropriately, but the consequences of an accident are still quite high. "Oil spills are terrible events," said Scarborough Bull, "and if you put a platform on and drill and produce oil, you always have some risk."
However, these clumsy structures, which rise hundreds of meters from the bottom of the ocean, provide a unique habitat. A complex form of platform support creates a three-dimensional ridge for animals to colonize and live close to. An open platform design allows the current to pass, bringing nutrients.
"We say," Oh, we will turn these platforms into reefs, "" Love said, "but as far as marine life is concerned, they are already ripped off. "
In 2014, Scarborough Bull and Love co-operate with colleagues at the Occidental College to assess the biological productivity of offshore oil platforms off the coast of California. Using standard models and metrics, the team compared platforms with all other sites where they could find information. The results of the study were astounding. "Platforms outside of California, as far as fish are concerned, were the most productive habitats in the world," Love recalls.
"More productive than coral reefs, more productive than the Chesapeake Bay," he continued. "Does this mean that they are really the most productive? Well, we do not know. But on the basis of world literature at the time, they were the most productive habitat."
Perspectives on the reef effort vary from country to country and ideology. Those who have considerations of conservation want to restore the site to its original state. The European Union is currently following this policy and all dismantled platforms in the EU have to be completely removed. In the meantime, the practice of replenishing old platforms is now a routine in the Gulf of Mexico. Since 2016, more than 11 percent of the decommissioned platforms in the US Gulf have moved into constant reefs, according to Scarborough Bull. The region currently has over 500 rivals, not including those that are still part of the active platforms.
Oil companies benefit from the use of old platforms, but some conservators, fishermen and state governments have also found a reason to support this trend. "In the Gulf of Mexico, when you go fishing, go to the platform and get in touch with it directly," said Scarborough Bull, who spent 12 years in the region. "There is a different social thinking about the use and usefulness of parts of the platform that you do not have in California."
Decommissioning the platform usually implies its complete removal from the seabed, and then pulling for disposal or waste. This is an expensive offer. The latest estimate for removing all platforms from the California coast is $ 8 billion, says Scarborough Bull. Modifying the platform to serve as a permanent ridge greatly reduces these costs, especially those related to the extraction, cleaning and deposition of a supporting structure on the shore, which will have thousands of tons of marine life that are held with it until it recedes.
In order to turn the lower part of the platform into a permanent ridge, the structure must be free of hydrocarbons or other dangerous materials described in any federal, state or local law, rulebook, rule, regulation, decree, decree or request. However, this is still a far cheaper endeavor than complete removal. And the savings are not only used by the oil company, which pays 100 percent of the decommissioning costs. Coastal states that have reef laws require the company to share with the state a portion of the money that will save if the platform is overtaken and not removed; Often 50% savings, explained Scarborough Bull.
Moreover, the ridge and surrounding waters belong to the State and fall under its jurisdiction, even if the platform was in federal waters before being retired. Twenty-three platforms intended for decommissioning outside the California coast are found in federal waters, and one, Platform Holly, is in state waters, but deep enough to be considered for scratching.
The state assumes ownership and responsibility for the site after the ridge has been established, which involves taking appropriate steps to prevent the ridge from becoming a danger to transport. This includes mapping locations on maps and setting up to warn of any navigation hazard, depending on how close the ridge is to the surface. The study examines these practical considerations in detail, important factors in deciding how to retire the old platforms.
"It will be necessary to make decisions about more and more of these structures," says Ljubav. "We want everyone to have the same facts while entering the process, so decisions can be made on a rational basis."