A shipwreck off of Honduras.
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This is a royalty-free image from Pixabay.

Artificial reefs are something we hear about on a regular basis. There is a growing interest in creating artificial reefs for a few reasons: because of the destruction of natural reefs, which is hopefully slowing down, and because of the economic benefits of allowing a structure already in the ocean to remain there rather than having to remove it to dispose of it.

There are companies that specialize in creating artificial reefs where there is no current structure because not only are artificial reefs—at least in theory—good for the environment, but they also can create a boost to a tourism market. The more that artificial reefs attract and become a home for wildlife, the more they also attract tourists and divers. (They also attract fishing folks, who may take advantage of the growing livestock population legally or illegally but I won’t address that here.)

But what about structures that are already in the ocean for other purposes, like drilling. Could they become artificial reefs and stay where they are permanently?

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Very recently, researchers at University of California at Santa Barbara (UCSB) published a detailed study—perhaps the first ever—of the science and pragmatics of turning old offshore drilling rigs into reefs in Ocean and Coastal Management.

An offshore rig.
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This is a royalty-free image from Pixabay.

Decommissioning an oil or gas well on land is an expensive and complex process, although the costs vary significantly depending on where the rig is in the world and the environmental laws and regulatory climate that apply. Decommissioning an offshore drilling (or producing) platform is many times more expensive and complicated—and variable—depending on the distance from shore and the difficulty of getting materials to and from the platform, the depth of the water where the rig is located, and the water conditions and temperature.

The process of decommissioning an offshore well or rig has 10 generally agreed upon components at least in North America and western Europe: “project management, engineering, and planning; permitting and regulatory compliance; platform preparation; well plugging and abandonment; conductor removal; mobilization and demobilization of derrick barges; platform removal; pipeline and power cable decommissioning; materials disposal; and site clearance.”

These steps are the same ones required of on-land rigs, except that now you’re doing all these jobs perhaps miles out in the ocean in open water hundreds or thousands of feet deep. So, if you have to decommission an offshore rig, what may cost $5-$10 million in the Gulf of Mexico close to shore and not that deep can cost hundreds of millions when the rigs are further out to sea where it’s deeper and where large port cities are far away.

There are also several different types of offshore rigs; there is by no means a one-size-fits-all solution.

So, if rigs could be turned into permanent reefs, an oil business can shortcut some of this process. The well A) still has to be capped and plugged, and B) casing removed down to a certain depth dictated by which regulatory body governs, C) and all traces of petroleum and other chemicals have to be removed above and below the water line, etc. etc. etc.

The big difference here is that if there is to be a an artificial reef, the structure itself, the scaffolding, can stay where it is, and in some cases some parts or all of the platform (above water) can stay. That means that immense structure going down to the sea floor and building on the surface doesn’t have to be broken down, transported away and disposed of at enormous cost.

Furthermore, moving these rigs to dispose of them is fraught with the peril of introducing potential pest or invasive species to other areas, miles or hundreds of miles away, if the rig structure is not cleaned of all encrusting organisms before the move.

There are somewhere between 850 to 8000 offshore rigs more or less producing in different parts of the world depending on who you ask. These rigs have a producing life of a few years up to maybe 20 years. They must be decommissioned within a few years of halt in production.

It appears, according to the research paper referenced, that after a few years, rig structures are heavily colonized with marine life including corals and molluscs, alga and microfauna, and are heavily visited by fish. So, the idea of leaving the rig in place, provided all the other requirements are followed, is a win-win for everyone: the livestock gets to stay where it already is, and the oil company saves some money.

Partial rig removal is another option to consider. I don’t mean to give the impression here that I’m pro oil company at any cost. I have no dog in this fight. The fact is by not doing a rig-to-reef project during decommissioning, the oil company could be destroying a sophisticated and mature habitat that already exists beneath the water line. Of course, what damage has already been done to the environment by drilling there in the first place is beyond the scope of this article.

What is beyond question is that within the next 10 years, hundreds of offshore rigs will be decommissioned worldwide. The authors of the UCSB may be primarily preoccupied with the rigs off the coast of California (about 30), but what they have to say applies everywhere.

We all know about how old shipwrecks or sunken ships can turn into artificial reefs and that these structures are attractive to experienced scuba divers. Even the undersides of piers or jetties can become a habitat for marine life.

The underside of a jetty.
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This is a royalty-free image from Pixabay.

So, the big question is should we leave in place these offshore rigs that have an already-established marine ecosystem or have the potential to develop an ecosystem like that? Should we leave them intact or in part? Should the building above the water line stay too--for ease of docking boats or visiting tourists?

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Note from the Editor: This happens to be a topic I know something about because I worked for an oil company for 15 years and participated in the decommissioning of wells no longer in production on land. Canada has a very strict and arduous regulatory environment, and the process of decommissioning or “abandoning” wells is a long, difficult, and Byzantine process.

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References:

https://www.news.ucsb.edu/2019/019327/rigs-reefs

https://www.sciencedirect.com/science/article/pii/S0964569118304484

https://oceanservice.noaa.gov/facts/artificial-reef.html

https://www.offshore-mag.com/articles/print/volume-77/issue-7/departments/data/worldwide-offshore-rig-count-and-utilization-rate.html

https://petrowiki.org/Offshore_decommissioning

http://blogs.discovermagazine.com/d-brief/2018/08/20/oil-rigs-support-coral-reefs/#.XFdFWM9KjOQ

https://daily.jstor.org/can-oil-rigs-grow-into-ocean-reefs/

http://www.esa.org/pdfs/Macreadie.pdf

https://www.rigzone.com/training/insight.asp?insight_id=354

Brooks, J.M., C. Fisher, H. Roberts, E. Cordes, I. Baums, B. Bernard, S. Brooke, R. Church, A. Demopoulos, P. Etnoyer, C. German, E. Goehring, C. Kellogg, I. McDonald, C. Morrison, M. Nizinski, S. Ross, T. Shank, D. Warren, S. Welsh, G. Wolff. 2012. Exploration and research of northern Gulf of Mexico deepwater natural and artificial hard-bottom habitats with emphasis on coral communities: Reefs, rigs, and wrecks—“Lophelia II” Interim report. U.S. Dept. of the Interior, Bureau of Ocean Energy Management, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study BOEM 2012-106. 126 p.

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Author Profile: Cynthia White

Cynthia received her BA in English from NYU a long long time ago. She has been a freelance writer and editor for over 20 years. Now she is a writer and editor on staff at R2R, where her forum nickname is Seawitch.