A growing concern that increasing levels of greenhouse gases in the atmosphere are contributing to global climate change has led to a search for economical and environmentally sound ways to reduce carbon dioxide (CO 2) emissions. One promising approach is CO 2 capture and permanent storage in deep geologic formations, such as depleted oil and gas reservoirs, unminable coal seams, and deep brine-containing (saline) formations. However, successful implementation of geologic storage projects will require robust monitoring, verification, and accounting (MVA) tools. This article deals with all aspects of MVA activities associated with such geologic CO 2 storage projects, including site characterization, CO 2 plume tracking, CO 2 flow rate and injection pressure monitoring, leak detection, cap-rock integrity analysis, and long-term postinjection monitoring. Improved detailed decision tree diagrams are presented covering the five stages of a geologic storage project. These diagrams provide guidance from the point of site selection through construction and operations to closure and postclosure monitoring. Monitoring, verification, and accounting techniques (both well-established and promising new developments) appropriate for various project stages are discussed. Accomplishments of the Department of Energy (DOE) Regional Carbon Sequestration Partnerships field projects serve as examples of the development and application to geologic storage of MVA tools, such as two-dimensional and three-dimensional seismic and microseismic, as well as the testing of new cost-effective monitoring technologies. Although it is important that MVA and computer simulation efforts be carefully integrated to ensure long-term success of geologic storage projects, this article is limited to a discussion of MVA activities. This article is an extension of a report published in 2009 by the DOE National Energy Technology Laboratory titled, "Best Practices for Monitoring, Verification, and Accounting of CO 2 Stored in Deep Geologic Formations," to which interested readers are referred for
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.