Transition from old oil platforms to permanent reefs – ScienceDaily

Although decommissioning a platform is a difficult task, a growing number of people have found a new goal as artificial reefs. Researchers at UC Santa Barbara have published in the journal a comprehensive study of the history, ecology and pragmatics of efforts to move from reefs to reefs. Oceans and coasts management.

Scientists hope that this study will not only allow California residents and policymakers to decide on the use of retirement platforms off its shores.

"California citizens will have to make decisions about the continued existence of vast marine life under the platforms, and they must make informed decisions," said Ann Scarborough Bull, researcher at Marine Science Institute (MSI) of the University of Santa Barbara, and to the main author newspaper. This question will come back time and again to the world as platforms age and existing oil fields reduce their production.

Scarborough Bull worked for nearly 30 years as an environmental badyst and researcher at the Department of the Interior's Mineral Management Department, now the Bureau of Ocean Energy Management. She joined UC Santa Barbara after retiring as chief of environmental science for the west coast.

In 2017, the organizers of an industry summit on the decommissioning of oil wells invited Scarborough Bull to talk about the scientific underpinnings of the transition from permanent reef platforms. At the time, she discovered that the literature on the subject was rudimentary and fragmented. After joining the university, Bull decided to compile the scattered information into a basic article to which she added the results of her own extensive research.

"As far as we know, this document is the first of its kind," said biologist-researcher Milton Love, also of MSI, who co-authored the study with Scarborough Bull.

An ecological quirk

There is no doubt that oil from these platforms has a negative impact on the environment. And the possibility of destructive oil spills still exists when oil production and water mix. Risks can be minimized if the work is done properly, but the consequences of an accident are still quite high. "Oil spills are terrible events," said Scarborough Bull, "and if you install a rig and you drill and produce oil, you still have a level of risk."

However, these imposing structures, rising hundreds of feet from the bottom of the ocean, provide a unique habitat. The complex shape of the platform support creates a three-dimensional reef that animals can colonize and live nearby. And the open construction of the platform allows the currents to pbad through, bringing nutrients.

"We say," Oh, we're going to turn these platforms into reefs, "said Love, but in marine life, they're already reefs."

In 2014, Scarborough Bull and Love collaborated with colleagues at Occidental College to badess the biological productivity of offshore oil rigs off California. Using standard models and metrics, the team compared the platforms to all the other habitats on which they could find information. The results of the study were staggering. "The offshore platforms around California, with respect to fish, were the most productive habitats in the world," Love said.

"More productive than coral reefs, more productive than Chesapeake Bay," he continued. "Now, does that mean that they are really the most productive? Well, we do not know it. But according to the world literature of the time, they were the only ones in the world. the most productive habitat. "

Views on reef platform efforts vary across countries and ideologies. Those with a preservationist mentality want to restore the site to its original state. The EU is currently following this policy and all platforms decommissioned in the EU must be completely removed. Meanwhile, the practice of picking up old platforms is now common in the Gulf of Mexico. According to Scarborough Bull, in 2016, more than 11% of decommissioned platforms in the US Gulf had been transformed into permanent reefs. The region currently has more than 500 rig reefs, not counting those that are still part of active platforms.

Oil companies have everything to gain from the old platform, but some ecologists, fishermen and state governments have also found reasons to support this trend. "In the Gulf of Mexico, when you go fishing, you go directly to a platform and attach to it directly," said Scarborough Bull, who has spent 12 years in the region. "The company has a different conception of the use and utility of certain parts of the platforms that you do not have in California."

A daunting task

The decommissioning of a platform usually involves its complete removal from the seabed, and then its transport to disposal or disposal. It's a pricy proposition. The latest estimate for the removal of all platforms off the California coast raises to $ 8 billion, said Scarborough Bull. Changing the platforms to permanent reefs significantly reduces these costs, particularly those related to the transportation, cleaning and disposal of the shore support structure, to which thousands of tonnes of marine life have been deposited. will hang at the time of retirement.

To transform the bottom of the platform into a permanent reef, the structure must be free from any hydrocarbon or other hazardous material described in any applicable federal, state or local law, ordinance, rule, regulation, or requirement. Still, this remains a much cheaper venture than total elimination. And the savings do not only benefit the oil company, which bears 100% of dismantling costs. Coastal states that have reefing platform laws require the company to share with the state some of the money that it will save if a platform is scrapped rather than removed. . often 50% of cost savings, explained Scarborough Bull.

In addition, the reef and the surrounding surrounding waters belong to the state and fall within its jurisdiction, even though the platform was in federal waters prior to its retirement. Twenty-three platforms to be decommissioned off the coast of California are in federal waters and one of them, the Holly platform, is in state waters, but enough deep to be taken into account for the reefing.

The State badumes the title and responsibility of the site once the reef is established, which includes taking appropriate measures to prevent the reef from becoming a danger to navigation. This involves registering the position on maps and installing buoys to warn of any danger to navigation, depending on the proximity of the reef to the surface. The study discusses at length these practical considerations, important factors in deciding how the old platforms will be retired.

"Decisions will have to be made regarding more and more of these structures," said Love. "We want everyone to have the same facts as they enter the process so that decisions can be made on a rational basis."