SECARB OFFSHORE: UNDERSTANDING THE POTENTIAL FOR SUBSEA CO2 STORAGE IN THE EASTERN GULF OF MEXICO

An estimated 40% of U.S. anthropogenic CO₂ emissions are generated in the Southeast with a large portion of these emissions generated within 100 km of the coastline; this makes offshore geologic carbon dioxide (CO₂) subsea storage in the Gulf of Mexico (GOM) an attractive prospective. The project, “Southeast Regional Carbon Storage Partnership: Offshore Gulf of Mexico” (SECARB Offshore), is assembling the knowledge base required for secure, long-term, large-scale CO₂ subsea storage in the GOM with or without CO₂ enhanced hydrocarbon recovery (CO₂-EOR). SECARB Offshore supports the Department of Energy’s (DOE) long-term objective to ensure a comprehensive assessment of the potential to implement offshore CO₂ subsea storage in all Bureau of Ocean Energy Management (BOEM) Outer Continental Shelf (OCS) Oil and Gas Leasing Program Planning areas in the GOM.

While onshore resources in the southeastern U.S. have been well-quantified, offshore resources are less understood and have different technical challenges. Building on the preliminary work conducted in previous studies, SECARB Offshore is undertaking a comprehensive resource characterization in the eastern GOM with more detailed evaluation of storage opportunities in federal and state waters (exclusive of Texas state waters), in active and depleted oil and gas fields (including those potentially associated with CO₂-EOR) as well as deep saline aquifers. When available, existing data are being utilized, with gaps being identified and addressed when possible.

Quantifying the potential resources is only the first step in understanding the potential for subsea CO₂ storage in the eastern GOM. Monitoring techniques will require modifications to address the unique challenges presented by offshore subsea CO₂ storage. For example, onshore monitoring often utilizes dedicated monitoring wells; this could be prohibitively expensive in an offshore setting. Thus, alternative monitoring methodologies are being evaluated as part of SECARB Offshore.