CO2 Injection and Sequestration in Depleted Oil and Gas Fields and Deep Coal Seams: Worldwide Potential and Costs

Abstract

Three petroleum extraction technologies offer potential for large‐scale, low‐cost, and long‐term sequestration of carbon dioxide. Enhanced oil recovery (EOR) using CO2 injection is a commercially proven process with more than 120 Gt of “value added” CO2 sequestration potential worldwide. Enhanced gas recovery (EGR) using CO2 injection is conceptually feasible but has not yet undergone testing. Depleted natural gas fields offer more than 750 Gt of moderate‐cost CO2 sequestration potential, not including EGR. Enhanced coal‐bed methane (ECBM) recovery using CO2 injection is undergoing pilot testing in the United States, with favorable early results. ECBM could be used to sequester more than 150 Gt of CO2 in coal basins worldwide. Challenges facing large‐scale application of geologic sequestration in hydrocarbon fields include: (1) high capture and processing costs of anthropogenic CO2; (2) inadequate understanding of many petroleum and coal reservoirs, particularly in frontier areas; (3) rigorous monitoring and verification to convince regulators and the public at large that sequestration is secure and long term; (4) achieving recognition and certification from emissions trading systems; and (5) resolving operational conflicts between sequestration and enhanced recovery. These challenges could be overcome by building on existing technologies from the EOR, underground gas storage, and natural CO2 production and transportation industries and by targeted basic and applied R&D.

Scraping the bottom of the barrel: greenhouse gas emission consequences of a transition to low-quality and synthetic petroleum resources

“…The amount of CCS capacity available through EOR projects is highly field-specific and still a matter of debate. Stevens et al (2001) cite CO 2 injection ratios of 0.3 tonne CO 2 per bbl of EOR output. However, much of this CO 2 is recycled in the production process, so all of it does not stay sequestered.…”

A New Coal-Permeability Model: Internal Swelling Stress and Fracture–Matrix Interaction

“…Geological sequestration of CO 2 is widely regarded as an essential component of a portfolio of approaches needed to reduce such emissions (Pacala and Socolow 2004). Because of the high internal surface area of coal, a comparatively large volume of CO 2 can be stored as adsorbed gas in coal seams (Stevens et al 2001;Cui et al 2007). At the same time, the sequestration into coals displaces methane (CH 4 ) from coal and thus gives rise to enhanced production of coalbed methane.…”

The future of Carbon Capture and Storage (CCS) in Nigeria

“…This technique helps to extract an additional 5 to 20 % of the original oil in place from depleted or marginal wells (Tzimas et al, 2005;Stevens et al, 2001). Two processes have been developed for CO2-EOR.…”

“…These are miscible displacement and immiscible displacement (Tzimas et al, 2005). Under favourable reservoir conditions (generally >22 ºAPI oil gravity and >1200 m reservoir depth), injected supercritical CO2 becomes miscible with residual oil (Stevens et al, 2001). When injected, it decreases oil viscosity and improves its mobility, thus increasing oil recovery.…”