Enhanced Oil Recovery

The DOE and NETL have a long history of conducting research focused on using thermal, chemical and miscible methods to enhance recovery from conventional oil reservoirs. This has included fundamental research on the development of chemical foaming agents for thickening carbon dioxide (CO₂) to improve vertical conformance in CO₂ floods, easy-to-use models that small producers can apply to determine if their reservoirs are good candidates for enhanced oil recovery (EOR), and comprehensive evaluations of incremental EOR production potential across the nation’s major producing reservoirs.

Due to the physics of fluid flow, as much as two-thirds of conventional crude oil discovered in U.S. fields remains unproduced – primary oil recovery produces only about 10 percent of the reservoir’s original oil in place, with secondary recovery techniques extending a field’s production life and increasing original oil in place production to approximately 20 to 40 percent. Tertiary (enhanced) techniques prolong the life of producing fields, ultimately leading to recovery of 30 to 60 percent of the original oil in place. Even with secondary and tertiary techniques, however, large volumes of oil can be left in the reservoir.

Additionally, hydrocarbons reservoirs that have unconventional characteristics (such as oil in fractured shale source rocks, kerogen in oil shale, or bitumen in tar sands) constitute a vast potential domestic supply of energy.

The application of EOR methods to overcome the physical forces holding hydrocarbons underground can turn these accumulations into domestic oil reserves capable of supporting economic growth for decades to come. CO₂ injection for miscible flooding, already the most common EOR method, holds even greater promise if it can be more widely applied to mature oil fields across the country rather than only in fields close to natural sources of CO₂. The re-injection of natural gas associated with oil production is also being investigated as a mechanism for EOR; this not only enables incremental recovery – it also reduces the need for flaring of natural gas during production.

Accelerated development of EOR technologies will allow the U.S. to take advantage of new opportunities to: (1) maintain our growing energy independence by augmenting new sources of tight oil production, (2) economically utilize captured CO₂ while reducing emissions, (3) optimize the use of associated gas, and (4) maximize the lifetime utility of existing infrastructure and wells in mature conventional fields.

Building on DOE’s history of supporting the development of advanced EOR technologies, the current research program has expanded to cover not just conventional reservoir EOR topics but also unconventional reservoir EOR.

At the present time, DOE is funding field-based research focused on:

• Next generation CO₂-EOR technologies that can increase recovery from existing CO₂-EOR projects and accelerate application of the process to other mature oil fields around the country.
• Novel EOR methods that can reduce the environmental risks of onshore oil production and remediate areas that have been impacted by historical production activities.
• Ways to improve the performance and lower the cost of chemical floods, as well as ways to accelerate their application by independent producers, which are the most likely operators of mature U.S. oil fields.
• Methods for enhancing recovery of hydrocarbons locked in unconventional reservoir rocks like the Bakken shale or that have characteristics that make their production difficult (such as heavy oil in Arctic reservoirs).

Reports

Offshore Spill Prevention Research Program

EOR – Unconventional Field Test Sites

CO₂ as a Recovery Agent Overview Brief

NETL implements this effort as part of DOE’s Oil & Gas Program.