Oil and gas platforms are found in oceans globally. The steel giants are found in water depths ranging from less than 50 m to over 1,800 m below the surface—the equivalent height of a 550-story building. The complex platform infrastructure spans the entirety of the water column, offering marine habitat with few natural parallels. In the offshore marine environment, hard substrate, such as rocky outcrops and coral reefs, are comparatively rare, further adding value to the habitat provided by the platform jacket. Over their operational lifespan, the structural steel of the platforms effectively serves as an oasis in the open ocean by providing habitat where none existed before. Over time, offshore oil and gas platforms can transform into thriving artificial reefs, which support diverse marine life communities with varying depth ranges co-existing within one reef.
Inadvertently, the traditional purpose of an oil and gas platform has expanded beyond fossil fuel extraction. In as little as a few weeks after installation, encrusting organisms, like sponges, barnacles, and corals, begin forming colonies that eventually cover the surface of the platform jackets. These pioneering species, in turn, provide habitat and resources to support fish communities of greater than 10,000 individuals. Fish communities can include small cryptic fishes as well as other reef and pelagic fishes. In many regions of the world, platforms provide critical habitat to adult and juvenile commercially valuable fisheries species. As such, oil and gas platforms have been shown to support some of the most diverse and productive ecosystems found in the marine environment.
Numerous studies have documented marine life found inhabiting platform infrastructure as well as the ecosystems services that platforms provide (e.g., fisheries production). For example, in the Gulf of Mexico, the installation of thousands of oil and gas platforms facilitated the Gulf-wide expansion of the red snapper fishery which provided economic growth for regional coastal communities. In the North Sea, platforms have been shown to support large aggregations of Atlantic cod and function as spawning sites for many fish and invertebrate species. In California, platforms located in the Southern California Bight have been described as some of the most productive marine habitats in the world. Globally, offshore oil and gas platforms have provided important ecosystem services for members of the Blue Economy, like divers and fishers, by increasing accessibility to reef habitat. However, as the atmosphere surrounding offshore petroleum-based energy shifts in favor of renewable energy sources, such as wind, decommissioning of the world’s oil and gas platforms is rapidly increasing.
Traditional decommissioning involves complete removal of all platform and subsea infrastructure with the intention of returning the marine environment to its original state. Under a complete removal scenario, the oil wells are capped, and the platform legs are severed at the seafloor for recycling or scrapping onshore. This process results in marine life mortality and the loss of artificial reef habitat. The impending removal of our world’s offshore oil and gas platforms have raised many questions and concerns regarding implications of removing these structures on the marine environment and the impacts to members of the Blue Economy that utilize the resources provided by these structures. In regions like the Gulf of Mexico where natural reef is limited, the widespread removal of platforms is likely to have regional implications for the distribution of marine life and population size of fisheries species. Therefore, in response to concerns from fishers, the US established a National Artificial Reef Plan which recognized the ecological, economic, and social value of oil and gas platforms leading to the establishment of the first Rigs-to-Reefs (RtR) program.
The Partial Removal Method of Reefing a Rig
A Win-Win Solution
Rigs-to-Reefs provides an alternative decommissioning option to complete platform removal. In the Gulf of Mexico, a RtR decommissioning scenario typically involves an oil company making the decision to decommission a platform structure and applying to donate it to the appropriate state artificial reef program. This alternative involves modifying the platform’s infrastructure to preserve the marine life and habitat provided by that platform. To decommission via reefing, the oil well is capped, and the platform jackets are either toppled in place, towed to another location, or severed 85 feet below the surface leaving the remaining portion of the jacket in place.
Decommissioning via a reefing option is typically more cost-effective, and less labor-intensive, for an operating company in comparison to complete removal. By donating a platform to a RtR program, the operating company may potentially save millions of dollars in decommissioning costs. Due to the willingness of operators to participate in the RtR program and with the support of local fishing and diving communities, the Gulf of Mexico’s RtR program has had great success with over 550 offshore oil and gas platforms converted to permanent artificial reefs since the 1980s.
Despite the success enjoyed by the RtR program in the Gulf of Mexico, other regions around the world have shown hesitancy in establishing their own RtR programs. Considerations concerning liability, feasibility, and conflicting stakeholder opinions have kept many regions from moving forward with program establishment. However, as the ecological and economic value of offshore platforms is realized, more and more operators are considering the feasibility of decommissioning their assets via a reefing option.
However, not every platform is a good candidate for a RtR conversion. Considerations for the platform’s location, water depth, stability, structural complexity, and age, among other features must be assessed on a case-by-case basis to determine the reefing viability of any platform candidate. Prior to submitting a decommissioning application, an operator must first prove that the resulting reef would provide an overall net benefit to the marine environment. Therefore, before becoming a reefing candidate, a platform must first undergo extensive ecological evaluations to assess any potential value it might add to the local ecosystem as well as any implications that reefing may have on the various user groups operating in the same finite space.
A federally certified company, Blue Latitudes is a women-owned, marine environmental consulting firm that specializes in identifying viable reefing candidates. We work alongside operators, regulators, fishermen, community stakeholders, and other members of the Blue Economy on reefing projects around the world. The company was recently awarded a National Science Foundation grant to quantify how fisheries use the highly productive artificial reef ecosystems found on offshore oil and gas platforms in the Gulf of Mexico. This project will seek to define the value of offshore platforms structures as a fisheries resource and extrapolate this valuation process as a model for current and future offshore development (e.g., wind installations).
The work that has been done so far is proof that, when appropriate, preserving the thriving ecosystems by reefing a rig can add value not only to the local ecosystems but also to stakeholders in the Blue Economy. RtR is a proven, replicable, and scalable solution that has the potential to transform how the world views the offshore energy industry and catalyze sustainable ocean resource development worldwide.