ASSESSING THE POTENTIAL FOR CARBON SEQUESTRATION IN DEPLETED HEAVY OIL RESERVOIRS USING ACOUSTIC LOGGING

Abstract

As global warming due to anthropogenic greenhouse gases, notably carbon dioxide threatens to take a catastrophic dimension, geological storage of carbon dioxide has been widely accepted as a technically and economically viable remediation strategy. Consequently, targeted geological repositories are saline aquifers, salt caverns, deep unmineable coal seams and depleted oil and gas reservoirs. For storage in depleted oil reservoirs, the stratigraphic trapping capability of overlying low permeability shale is the principal motivating factor for long term containment of anthropogenic gas in oil reservoir until its dissolution and final immobilization by mineral carbonation reactions. Consequently, where the development of the oil reservoir by thermal recovery can lead to thermal pressurization of the cap rock layer, the ability of such a depleted reservoir to contain anthropogenic carbon dioxide must be thoroughly investigated to assess its competency as a proposed geological repository. In this study, seismic theory coupled with that of heat transfer has been used to derive interval velocity for a heavy oil reservoir under thermal recovery. The resulting equation has been validated using published works from literature sources.