Frequently Asked Questions

Do the platforms corrode, and thus prove unstable?

Offshore oil and gas platforms are made of various types of steel including carbon, stainless, high strength low alloy, and weathering, which over time corrode, due to the highly corrosive nature of the ocean (MetalsUSA 2024). 

In a 2004 study, Love and Schroeder describe the sacrificial anodes, constructed of aluminum or zinc, that are used to safeguard against corrosion on operational oil and gas platforms.  These anodes  work by oxidizing more quickly than the steel of the platform jacket they are protecting, ensuring the structural integrity and longevity of the platforms. This cathodic protection typically endures for several decades as long as the anodes remain intact. Once a platform is reefed, it's assumed that there won't be any further replacement of sacrificial anodes, although this issue remains unaddressed for California platforms. While corrosion rates in seawater fluctuate based on factors such as water temperature and biofouling, it is estimated that the life span of a cathodically unprotected platform will range from a minimum of 100 to more than 300 years (Love and Schroeder 2004; Quigel and Thorton 1989; Mishael S J. Platform decommissioning corrosion estimate, Chevron Corporation, Unpublished Report,1997).

DO REEFED PLATFORMS POLLUTE THE SURROUNDING ENVIRONMENT?

Pollution around California’s platforms has been studied since the late 1970s. In a study published in 1976, Bascom and colleagues (Bascom et al. 1976) assessed pollution levels around oil platforms in the Santa Barbara Channel, by measuring trace metals such as cadmium, chromium, copper, lead, molybdenum, nickel, silver, vanadium, and zinc in the water near the platforms and the surrounding environment.

Their findings indicated that the levels of most trace metals were similar at both control sites (without platforms) and impact sites (with platforms), with the exception of vanadium, which was slightly higher near the platforms, but still did not occur at harmful levels. The researchers also found no unusual levels of hexane extractable materials, volatile solids, copper, or zinc near the platforms.

With regards to hydrocarbon levels, the researchers discovered that mussels and crabs collected from various locations near the platforms didn't contain any detectable amounts of hydrocarbons. This is notable because mussels typically  absorb petroleum hydrocarbons, yet there were no detectable levels found in their tissue.

Love et al. 2004 discuss a different way to gauge potential contamination, drawing from information provided by the California Department of Health Services. For over ten years, the California Department of Health Services has monitored toxin levels in mussels found on platforms. These mussels are harvested in large quantities and sold to restaurants in southern California for human consumption.

According to a state health official quoted in the LA Times, mussels residing on platforms in the Southern California Bight have ‘‘probably the highest quality of shellfish meat sold in California and may be the entire country’’ (LA Times 1994). This superior quality could be attributed to the offshore location of the platforms, which keeps them away from the pollution often associated with agricultural and urban runoff found in nearshore environments.

What is the establishment and maintenance costs for R2R?

In the Gulf of Mexico, where reefed platforms transition into the responsibility of the state, ongoing maintenance and operations for reefing programs, including Rigs to Reefs conversion and other artificial reefs, entail significant expenditures. States such as Louisiana allocate approximately $5-8 million annually to monitor and maintain over 400 converted platforms along its coastline, as well as other artificial reefs (LDWF 2019).

How do Reefed structures function as fish habitat?

After 30 years of observing and monitoring the marine ecosystems on oil platforms, research has suggested that these structures have evolved into economically and ecologically valuable ecosystems. For example, juvenile rockfish, several species of which are currently recognized as being overfished in the state of California, have been found to live in higher densities at several of the platforms as compared to nearby natural reefs. “In some locations, platforms may provide much or all of the adult fishes of some heavily-fished species and thus contribute disproportionately to those species larval production”(Love et al. 2003).  

Researchers suggest three reasons for the finding: (1), platforms physically occupy more of the water-column than most natural outcrops; (2), because there are fewer large fish in the mid-water habitat where the platforms are located, predation is likely lower; and (3), the location and size of offshore platforms “provide great delivery rates of planktonic food for young fishes”(Love et al. 2003). 

WHAT IS THE OLDEST KNOWN RIGS TO REEFS CONVERSION?

In Louisiana, the Department of Wildlife and Fisheries has been running a Rigs to Reefs program for more than 30 years. This initiative repurposes oil and gas platforms to serve as habitats in Louisiana's artificial reef program (Kasprzak 1998). The oldest known rigs to reefs conversion took place over forty years ago in Florida in 1979 with the relocation of an Exxon experimental subsea template from offshore Louisiana to a permitted artificial reef site off Florida (GulfBase 2024).