Rigs-to-Reefs (RTR) is the practice of converting decommissioned offshore oil and petroleum rigs into artificial reefs. Such biotic reefs have been created from oil rigs in the United States, Brunei and Malaysia. In the United States, where the practice started and is most common, Rigs-to-Reefs is a nationwide program developed by the former Minerals Management Service (MMS), now Bureau of Safety and Environmental Enforcement (BSEE), of the U.S. Department of the Interior.

An oil platform is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms will also have facilities to accommodate the workers, although it is also common to have a separate accommodation platform linked by bridge to the production platform. Most commonly, oil platforms engage in activities on the continental shelf, though they can also be used in lakes, inshore waters, and inland seas. Depending on the circumstances, the platform may be fixed to the ocean floor, consist of an artificial island, or float. In some arrangements the main facility may have storage facilities for the processed oil. Remote subsea wells may also be connected to a platform by flow lines and by umbilical connections. These sub-sea facilities may include one or more subsea wells or manifold centres for multiple wells.