What is decommissioning of offshore platforms?

What is decommissioning of offshore platforms?

Decommissioning is the process of ending offshore oil and gas operations at an offshore platform and returning the ocean and seafloor to its pre-lease condition. The Outer Continental Shelf Lands Act (OCSLA) and implementing regulations establish decommissioning obligations to which an operator must commit when they sign an offshore lease under the OCSLA, including the requirement to apply for and obtain a permit for subsequent removal of platforms. Outer Continental Shelf (OCS) leases typically require the operator to remove seafloor obstructions, such as offshore platforms, within one year of lease termination, or prior to termination of the lease if either the operator or the Department of the Interior deems the structure unsafe, obsolete, or no longer useful for operations. The OCSLA regulatory and lease requirements for decommissioning offshore platforms are designed to minimize the environmental and safety risks inherent in leaving unused structures in the ocean, and to reduce the potential for conflicts with other users of the Federal OCS (i.e., commercial fishing/aquaculture, military activities, transportation industry, other oil and gas/renewable energy operations, etc.). Decommissioning an offshore platform generally entails: Plugging all wells supported by the platform and severing the well casings 15 feet below the mudline; Cleaning and removing all production and pipeline risers supported by the platform; Removing the platform from its foundation by severing all bottom-founded components at least 15 feet below the mudline; Disposing the platform in a scrap yard or fabrication yard, or placing the platform at an artificial reef site; and Performing site clearance verification at the platform location to ensure that no debris or potential obstructions to other users of the OCS remain. OCSLA regulations administered by the Bureau of Safety and Environmental Enforcement (BSEE) require that operators obtain approval of the platform removal methodology prior to removal of the platform through an application process. To satisfy National Environmental Policy Act obligations, the Bureau of Ocean Energy Management (BOEM) prepares a site-specific environmental assessment for each removal application on behalf of BSEE. BSEE ensures the assessment is adequate and imposes any necessary protective mitigation measures as conditions of permit approval.