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<p>The rising carbon dioxide emissions contributing to climate change has lead to
the examination of potential ways to mitigate the environmental impact. One such method
is through the geological sequestration of carbon (CCS). Although there are several
different forms of geological sequestration (i.e. Saline Aquifers, Oil and Gas Reservoirs,
Unminable Coal Seams) the current projects are just initiating the large scale-testing
phase. The lead entry point into CCS projects is to combine the sequestration with
enhanced oil recovery (EOR) due to the improved economic model as a result of the
oil recovery and the pre-existing knowledge of the geological structures. The potential
scope of CCS-EOR projects throughout the continental United States in terms of a systematic
examination of individual reservoir storage potential has not been examined. Instead
the majority of the research completed has centered on either estimating the total
United States storage potential or the potential of a single specific reservoir.</p><p>The
purpose of this paper is to examine the relationship between oil recovery, carbon
dioxide storage and cost during CCS-EOR. The characteristics of the oil and gas reservoirs
examined in this study from the Nehring Oil and Gas Database were used in the CCS-EOR
model developed by Sean McCoy to estimate the lifting and storage costs of the different
reservoirs throughout the continental United States. This allows for an examination
of both technical and financial viability of CCS-EOR as an intermediate step for future
CCS projects in other geological formations. </p><p>One option for mitigating climate
change is to store industrial CO2 emissions in geologic reservoirs as part of a process
known as carbon capture and storage (CCS). There is general consensus that large-scale
deployment of CCS would best be initiated by combining geologic sequestration with
enhanced oil recovery (EOR), which can use CO2 to improve production from declining
oil fields. Revenues from the produced oil could help offset the current high costs
of CCS. </p><p>The cumulative potential of CCS-EOR in the continental U.S. has been
evaluated in terms of both CO2 storage capacity and additional oil production. This
thesis examines the same potential, but on a reservoir-by-reservoir basis. Reservoir
properties from the Nehring Oil and Gas Database are used as inputs to a CCS-EOR model
developed by McCoy (YR) to estimate the storage capacity, oil production and CCS-EOR
costs for over 10,000 oil reservoirs located throughout the continental United States.
</p><p>We find that 86% of the reservoirs could store ≤1 y or CO2 emissions
from a single 500 MW coal-fired power plant (i.e., 3 Mtons CO2). Less than 1% of the
reservoirs, on the other hand, appear capable of storing ≥30 y of CO2 emissions
from a 500 MW plan. But these larger reservoirs are also estimated to contain 48%
of the predicted additional oil that could be produced through CCS-EOR. The McCoy
model also predicts that the reservoirs will on average produce 4.5 bbl of oil for
each ton of sequestered CO2, a ratio known as the utilization factor. This utilization
factor is 1.5 times higher that arrived at by the U.S. Department of Energy, and leads
to a cumulative production of oil for all the reservoirs examined of ~183 billion
barrels along with a cumulative storage capacity of 41 Mtons CO2. This is equivalent
to 26.5 y of current oil consumption by the nation, and 8.5 y of current coal plant
emissions.</p>
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