POTENTIAL FOR CARBON CAPTURE AND STORAGE (CCS) IN THE EASTERN GEORGES BANK BASIN, OFFSHORE MASSACHUSETTS

Carbon capture and storage is a potentially valuable strategy for reducing anthropogenic emissions of carbon dioxide (CO₂). Offshore storage in saline reservoirs may be implemented close to large point-sources of CO₂ while avoiding the land-based storage complications of NUMBY (not under my backyard). A high-level storage resource assessment of the East Georges Bank Basin is being performed as part of the Mid-Atlantic U.S. Offshore Carbon Storage Resource Assessment Project under the U.S. Department of Energy's Carbon Storage Program. The East Georges Bank Basin (EGBB) is ~ 160 km ESE of Cape Cod, MA, 100,000 km² in area, and contains sediments over 6.5 km thick. The average water depth is ~80 m. Ten exploratory wells drilled between 1976 and 1982 provide wireline log data, which we have used to investigate storage potential two middle Cretaceous-age sand units: the Logan Canyon and the Missisauga Formations. Gamma ray logs show general lithologies and are used to correlate formations. Neutron porosity and density porosity log data, coupled with published permeability and porosity data, enable us to evaluate the suitability for storage, including potential capacity and identification of seals. Sand units within both formations vary between 30 and 100 m thick, and have excellent porosity (average 25-35%) and permeability (over 1000 mD). These target intervals are located deep enough to maintain the pressure required to store liquid CO₂, yet shallow enough to be cost-effective drilling targets. Both potential reservoirs also underlie shale units that appear to be sufficiently thick and impermeable seals for containing injected CO₂. All these factors support EGBB as a favorable storage location. We are currently reprocessing 1970’s vintage multichannel seismic profiles to help further evaluate the reservoirs and seals within this subsea basin.