GEOLOGIC CARBON DIOXIDE SEQUESTRATION AND ENHANCED OIL RECOVERY

Based on current projections by the Energy Information Administration (2011, http://www.eia.gov/forecasts/aeo/) electrical power demand in the United States will increase about 30% by the year 2035. The combustion of fossil fuels, which will be used to generate most of the electricity in both industrialized and developing countries for years to come, is a major source of carbon dioxide (CO₂) emissions to the atmosphere. These emissions may potentially contribute to global warming as a greenhouse gas. Overall reduction of CO₂ emissions from the combustion of fossil fuels will likely involve a combination of techniques, ranging from energy conservation to increased fuel efficiency. Sequestration of CO₂ in geological reservoirs is another potential option, and existing knowledge derived from the oil and gas production industries has already helped to solve some of the technological challenges.

Geologic CO₂ sequestration coupled with enhanced oil recovery (EOR), by injecting anthropogenic CO₂ into existing hydrocarbon reservoirs, can increase the U.S. hydrocarbon recoverable resource volume and help prevent CO₂ release to the atmosphere. However, there are many challenges that must be overcome before there is large-scale implementation of geologic CO₂ sequestration projects and use of anthropogenic CO₂ for EOR purposes including limited anthropogenic CO₂ capture facilities, pipeline infrastructure, and unfavorable economic conditions.

In 2007, the Energy Independence and Security Act (Public Law 110–140) authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for CO₂ in consultation with the U.S. Environmental Protection Agency, the U.S. Department of Energy and State geological surveys. A team of USGS geologists working with other State and Federal agencies are currently defining CO₂ storage assessment units (SAUs) and estimating the CO₂ sequestration capacity in buoyant and residual storage traps within major U.S. sedimentary basins. In collaboration with industry, university, and government partners, USGS plans to develop an assessment methodology that can be used to estimate the potential volumes of technically recoverable hydrocarbons using CO₂-EOR and associated CO₂ sequestration in oil and gas fields.