Rigs-to-Reefs

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.Brian Twomey
Artificial Reefs
CCOP/EPPM Workshop on End of Concession & Decommissioning, 12–14 June 2012. (PDF) 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.

The program has been generally popular with fishers, the oil industry, and government regulators in the Gulf of Mexico, where offshore platforms develop into coral reefs, and as of September 2012, 420 former oil platforms, about 10 percent of decommissioned platforms, have been converted to permanent reefs.

Opposition in California has prevented a rigs-to-reefs program on the West Coast of the US. Similarly, environmental opposition has prevented implementation of Rigs-to-Reefs in the North Sea.

Overview

Inevitably, marine organisms attach themselves to the underwater portions of oil production platforms, transforming them into artificial reefs.

These platforms continue to function as long as the reservoirs underneath them provide oil at a profitable rate. At the end of their productive lives they must be decommissioned and removed (in the US within one year). An alternative to removal is to turn the rig into a reef through the Rigs-to-Reef (RTR) program. All coastal states in the US have such artificial reef programs in the interest of increasing ocean fisheries but not all participate in RTR. The rig's steel structures are stable and durable. They create shelter for marine life in open waters where there was none.

Note that production platforms are often called "rigs"; that terminology is used occasionally in this article—and indeed in the term Rigs-to-Reefs. Within the industry, "rig" refers to an apparatus with a derrick that can drill and service wells. (Most production platforms do not have such equipment installed.)

Process

Once a rig stops producing at economic rates, the site is usually abandoned. In the United States, the Minerals Management Service (MMS) requires the operator to remove the rig within a year of abandonment (stopped production) and lease end. MMS supports and encourages RTR as an alternative to total removal. RTR recognizes that during a rig's productive years, significant marine life comes to live on and around its structure. RTR preserves much of that marine life and encourages further growth. The operator benefits by avoiding the substantial cost of removal. Cumulative costs of removal had reached an estimated $1 billion by the year 2000. The shape and complexity of the structure may lead to significant species diversity.

Decommissioning a platform

Officially, decommissioning an oil rig is the act of removal according to regulatory requirements and includes flushing, plugging and cementing wells to make them safe. Decommissioning is complicated by factors such as cost, safety, operational duration, environmental issues, risk, experience, and historical relationship between operator and state.

As part of decommissioning, the operator must deal with the shell mound that collects on the bottom surrounding the rig. The mound forms on the pile of cuttings discharged from the original drilling operations, shells that have fallen from the platform's underwater structure, and material that has fallen and/or leaked from the platform, occasionally mixed with well seepage. Mounds can contain significant levels of toxic metals including, arsenic, cadmium, chromium, copper, nickel, PCBs, lead, zinc, and poly-nuclear hydrocarbons. Removing the rig structure does not eliminate the need to address the mound.

The method of decommissioning depends on water depth and structure type and is a three-step process that includes planning, permitting, and implementation. A party other than the operator usually administers the process.

In Louisiana, costs as well as the risk involved are the primary factors in determining how to decommission rigs. If the savings are large enough, the operator typically chooses reefing and donates 1/2 the savings to maintain the reef. Decommissioning a shallow water rig typically costs $10–15 million so the amounts can be substantial. The Louisiana Artificial Reef program from its inception through 1998 received roughly $9.7 million in donations and has not taken taxpayer money.

Methods of reefing

Severing the rig from the bottom using explosives is the easiest approach, but has the potential to harm marine life. This potential is greatly reduced if the explosives are all placed deep below the seafloor. Current requirements place the explosives a minimum of below the seafloor which eliminates the threat to all but the closest sea turtles. National Oceanographic and Atmospheric Administration (NOAA) National Marine Fisheries Service (NMFS) marine observers and helicopter surveys hours preceding the event keep most sea turtles away from the area. Alternatively, commercial divers can use mechanical and abrasive cutters, which preserves marine life, but places the divers at considerable risk.

Reefing involves one of three methods.:

* Tow and Place: Sever the structure from the sea floor and tow it to a state-approved location.
*Partial Removal: Remove the top portion of the submerged platform and either remove to the shore for salvage or place it on the sea floor nearby or at another site. Partial removal can result in a loss of the shell mound community and fish that live in the top section but the rest (the majority) of the habitat remains intact.
* Toppling: Toppling involves uses explosives to sever the base of the structure below the mud line in a matter such that it simply falls over. Toppling eliminates shallow and mid-ocean habitats. These portions of the rig are quickly occupied by other creatures.
* Augmentation and Integration: Augmentation and Integration involves adding additional structure to the reef site to enhance its value as a habitat and deliver additional ecosystem services.

United States

Offshore drilling began in California in the late 1800s from piers built out over the ocean. The United States began extracting oil offshore in the early 20th century and the first offshore oil platform in the Gulf of Mexico was built in 1947 off the Louisiana coast. "Today over 4,500 offshore oil and gas platforms have been installed supplying 25% of the United States' production of natural gas and 10% of its oil."http://www.wlf.louisiana.gov/fishing/programs/habitat/artificialreef.cfm Louisiana Department of Wildlife and Fisheries

The US Congress passed the Outer Continental Shelf Lands Act

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