Detailed Report on Carbon Dioxide Enhanced Oil Recovery (CO2 EOR)

This report provides a detailed overview of carbon dioxide enhanced oil recovery (CO2 EOR), a technology used to extract crude oil from reservoirs that are otherwise unproductive. It highlights the importance of CO2 EOR in increasing energy security, reducing greenhouse gas emissions through sequestration, and improving oil production compared to primary and secondary recovery methods. The report discusses various EOR techniques, including gas injection, thermal injection (steam and fire flooding), and chemical injection (polymer and microbial flooding), as well as the use of liquid carbon dioxide super fluids and water alternating gas (WAG). It addresses the safety aspects of CO2 EOR, emphasizing its excellent safety record and the existing regulations. Furthermore, it explores the physical properties affecting CO2 EOR, such as gas solubility, oil viscosity, density, and swelling factor. The report also includes a case study, examining oil production, suitable reservoirs, CO2 availability, anthropogenic sources of CO2, and US CO2 EOR demographics, ultimately concluding with recommendations for further development and implementation of CO2 EOR technology.

CARBON DIOXIDE ENHANCED OIL RECOVERY
CARBON DIOXIDE ENHANCED OIL RECOVERY
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CARBON DIOXIDE ENHANCED OIL RECOVERY
Executive Summary
The purpose of this report is to give a detailed illustration of what entails the carbon
dioxide enhanced oil recovery technology. This technology is one of the developments which
have been made in the energy sector. It has accelerated the production and utilization of
petroleum energy. CO2 EOR project is also seen to be a better method as it can ensure that high
amount of carbon dioxide is reused to reduce the emission of greenhouse gases through
sequestration.
The comparison of the oil produced before and after the introduction Carbon Dioxide in
Enhancing Oil Recovery project clearly shows how the CO2 EOR project has improved the
energy sector. The sourcing of carbon dioxide has enabled major companies in the collaboration
with the government to enable the rest of the crew to join in the project to reduce the emission of
carbon dioxide.

CARBON DIOXIDE ENHANCED OIL RECOVERY
Table of Contents
Table of Contents.............................................................................................................................3
List of tables....................................................................................................................................5
List of figures...................................................................................................................................6
1. Introduction..............................................................................................................................1
2. What is Carbon dioxide Enhanced oil Recovery process?.......................................................2
3. Techniques available for EOR process....................................................................................2
3.1. Gas injection.....................................................................................................................2
3.2. Thermal injection..............................................................................................................2
3.2.1. Steam flooding...........................................................................................................2
3.2.2. Fire flooding..............................................................................................................3
3.3. Chemical injection............................................................................................................3
3.3.1. Polymer flooding.......................................................................................................3
3.3.2. Microbial injection.....................................................................................................3
3.3.3. Liquid carbon dioxide super fluids............................................................................3
3.3.4. Water alternating gas (WAG)....................................................................................3
3.3.5. Plasma pulse..............................................................................................................4
4. Safety of CO2 EOR...................................................................................................................4
5. Physical properties affecting Carbon dioxide enhanced oil recovery......................................4
5.1. Carbon dioxide gas solubility...........................................................................................4
5.2. Carbon dioxide oil viscosity.............................................................................................5
5.3. The density of carbon dioxide...........................................................................................6
5.4. Swelling factor of carbon dioxide.....................................................................................6
6. Advantages and disadvantages of carbon dioxide enhanced oil recovery...............................7

CARBON DIOXIDE ENHANCED OIL RECOVERY
6.1. Advantages........................................................................................................................7
6.2. Disadvantages...................................................................................................................8
7. Case study of carbon dioxide EOR..........................................................................................8
7.1. The oil produced...............................................................................................................8
7.2. Suitable Reservoirs for Carbon Dioxide Enhanced Oil Recovery....................................9
7.3. Carbon Dioxide Availability...........................................................................................10
7.4. Anthropogenic sources of CO2.......................................................................................10
7.5. US CO2 EOR Demographics..........................................................................................11
Conclusion.....................................................................................................................................12
Recommendation...........................................................................................................................13
References......................................................................................................................................14

CARBON DIOXIDE ENHANCED OIL RECOVERY
List of tables
Table 1: Criteria for Screening Reservoirs for CO2 EOR Suitability...........................................10
Table 2: Major U.S. CO2 Operators (OGJ Biennial EOR Survey 2008)......................................11

CARBON DIOXIDE ENHANCED OIL RECOVERY
List of figures
Figure 1: Carbon dioxide gas solubility against the gas saturation pressure.................................11
Figure 2: Carbon dioxide oil viscosity against CO2 saturation pressure.......................................12
Figure 3: Carbon dioxide oil density vs carbon dioxide saturation pressure.................................12
Figure 4: Swelling factor against saturation pressure....................................................................13
Figure 5: Overview of how carbon dioxide assist produces trapped oil from a reservoir.............14

CARBON DIOXIDE ENHANCED OIL RECOVERY
1. Introduction
The Carbon Dioxide Enhanced Oil Recovery has received attention majorly in the United
States as they grapple with the situation at hand of depending on the foreign sources of energy
and greenhouse gas emission. The US government wants to reduce the depending on foreign
energy sources and reduce the emission of greenhouse gases. Carbon Dioxide on Enhanced Oil
Recovery has proven beyond doubt that it can simultaneously help the country to address some
priorities which are considered urgent. These include; increasing the energy security of the
nation – by reducing depending on oil from foreign countries which are unstable and hostile,
creation of job support, increasing the revenue through tax collection, US can also reduce the
trade deficit by locally manufactured oil instead of importing it (Pourabdollah, et al., 2013).
Another priority which the government can solve is protecting the environment by capturing and
storing the carbon dioxide from industries and power plants.
To help the situation to be understood the US government through the Department of
Energy has published the physics behind the use of Carbon dioxide to enhance the production
and recovery of the oil and natural gases.
During the extraction of oil from the underground, it is mixed with a solvent which can
extract it from the pores and surfaces of rocks underground. This has made the miners to use
solvents which were deemed expensive making the overall production of oil very expensive.
Fortunately, carbon dioxide has proven to be the best alternative as it is miscible with crude oil
and also less expensive. Carbon dioxide occur in underground deposits which is inexpensive to
extract and where they occur naturally as a gas, can make them to be extracted in very large
quantities. The carbon dioxide can also be produced through human activities and can be
extracted less expensively. These make carbon dioxide the best alternative for extracting oil from
the underground (Kok & Ors, 2012).
With high density, carbon dioxide is injected in the oil reservoirs it dissolves light
hydrocarbons. In areas where the pressure has reduced the oil field operators will now do the
viability of the field as it can increase the cost of extraction if adding pressure will be involved.
Pressure can be increased by injecting water in the oil reservoirs reducing the force between the
crude oil and the rock surface. This gives carbon dioxide easy time cleaning the crude oil from
the surface and the pores of the rocks. Another thing which help crude oil extraction using
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CARBON DIOXIDE ENHANCED OIL RECOVERY
carbon dioxide is that, when it dissolve in oil, the viscosity is reduced when it swells up making
the process even more efficient (Awang & Diyanti, 2010) (Sakthipriya, et al., 2016).
2. What is Carbon dioxide Enhanced oil Recovery process?
The carbon dioxide enhanced oil recovery (EOR) is a process applied to extract crude oil
from an oil field that could not have been extracted using any other technology. The use of the
EOR enables extraction of around 30% to 60% and above of a reservoir, thus is an advantage
over primary and secondary recovery whose application allows for extraction of only between
20% to 40% of a reservoir (Darche & Bourgeois, 2018). Based on the information from the
United States Energy department three primary techniques are available for the EOR process;
that is thermal, gas injection as well as chemical injection.
3. Techniques available for EOR process
3.1. Gas injection
The method referred to as gas injection or in another term miscible flooding is currently
the most popular approach applied in the EOR. Gas injection is a term used to generalize all the
injection processes that apply the introduction of miscible gases into a reservoir. This process
maintains the pressure of the reservoir as well as improve the displacement of oil as it reduces
the interfacial tension between water and oil. The gases that are used in this process includes
natural gas, nitrogen as well as carbon dioxide (Sahimi, et al., 2006). The fluid commonly used
in the displacement process is carbon dioxide as it reduces viscosity of oil and also less
expensive compared to liquified petroleum gas. This technology is dependent on the phase
behaviour of the mixture hence affected by pressure temperature as well as the composition of
crude oil.
3.2. Thermal injection
Under this approach a number of techniques are applied to heat the crude oil in the
reservoir to lower its viscosity and vaporize some of the oil. This reduces the mobility ratio. The
heat increases the permeability of the oil by reducing its surface tension, in addition the heated
oil may vaporize and then condensed creating an improved oil. The methide applied includes;
steam flooding, combustion as well as cyclic steam injection (Elias, 2013). The above methods
optimize the sweep efficiency as well as the displacement efficiency.
3.2.1. Steam flooding.
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CARBON DIOXIDE ENHANCED OIL RECOVERY
This style involved the introduction of heat into the oil reservoir through pumping steam
into the well in a similar manner as water injection criteria. The steam eventually condenses to
form hot water, the steam zone area involves the oil evaporating while in the hot water zone the
oil undergoes expansion. All this leads to expansion of the oil, drop on its viscosity as well as
increased permeability (Oilfield Glossary, 2019). The success of the process demands that it be
done in a cyclical manner.
3.2.2. Fire flooding.
The fire flooding technique is most effective when the saturation of the oil and its
porosity are high. Combustion releases heat within the reservoir which in turn reduces oil
viscosity and assists vaporize the water in the reservoir to steam. Th hot water, steam,
combustion gas as well as distilled solvents do act in unison to drive oil inform of the fire
towards the production wells (Jihong, et al., 2013).
3.3. Chemical injection
Chemicals such as alkaline or caustic solutions have been applied to aid mobility as well
as reduce the surface tension. Several techniques are applied in this process all of whose
efficiency depends on the cost of the chemicals as well as their absorption and loss onto the rock
containing the oil formation (Hakiki, et al., 2016).
3.3.1. Polymer flooding.
This method entails mixing a long chain of polymer molecules together with water so as
to increase the viscosity of water. It thus improves the vertical and areal sweep efficiency due to
the improved water to oil mobility ratio (Zerkalov, 2015).
3.3.2. Microbial injection.
This is part of the microbial enhanced oil recovery; it is rarely used as it is costly due to
unacceptability of its developments across most countries in the globe (Shibulal, et al., 2014).
3.3.3. Liquid carbon dioxide super fluids.
The use of carbon dioxide is very effective when the depth of the reservoirs exceeds 2000
ft. When applied under high pressure with lighter oils, carbon dioxide is miscible with the oil
yielding a resultant swelling of the oil hence reduces viscosity (Doelle & Lukaweski, 2013). Use
of carbon dioxide as a solvent is advantageous as it is economical compared to other miscible
fluids like propane and butane.
3.3.4. Water alternating gas (WAG).
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CARBON DIOXIDE ENHANCED OIL RECOVERY
The injection of WAG is another method that is applied under the EOR where water is used
together with carbon dioxide (Zekri, et al., 2011). When the water used has low salinity greater
oil removal is allowed in addition to greater geochemical interactions.
3.3.5. Plasma pulse.
This is the newest technology that is being applied in the United States as of 2013. Its
origin is in the Russian Federation and was funded by Skolkovo innovation centre. The plasma
pulse involved use of low energy emissions to produce an effect that all the other technologies do
have with minimal environmental consequence (Makarov, 2016).
4. Safety of CO2 EOR
Carbon dioxide is a non-flammable and non-explosive compound which is not defined as
a hazardous substance. It is though highly volatile. The CO2 have operated for over 40 years with
an excellent safety record which has not registered any serious injury or fatalities across the
period. Currently there are over 3900 miles of pipeline designed to ferry CO2 for the purpose of
EOR in the wells which are generating around 281000 barrels of oil in a day. The industry has
been active for decades guided by the existing regulations and policies at the local, state or
federal level. These policies do also regulate the geologic striae if the carbon dioxide. CO2 is
contained by a series of chemical and physical trapping mechanisms, the formations that have
held oil for centuries also have the capability to contain carbon dioxide with research showing no
evidence of the CO2 leakage (MIT Energy Initiative, 2011). Experiences carried out for over a
decade in commercial scale has shown that the use of carbon dioxide enhanced oil recovery can
be conducted in a way that pose no threat to the safety of human and the general environment.
5. Physical properties affecting Carbon dioxide enhanced oil recovery
The use of carbon dioxide miscible flooding has of recent become a very vital strategy in
the enhanced oil recovery method for obtaining residual oil. Additionally, the use of carbon
dioxide is environmentally friendly hence a very important agent in controlling the global
warming menace facing the universe. For this reason, it is important to have a clear
understanding of the relationship between the gas and the reservoir’s crude oil so as to improve
the efficiency of the carbon dioxide enhanced oil recovery technique (Mansoura, et al., 2019).
Below traits gives a more illustration of how carbon interacts with other physical components
and how this can be used to improve the oil obtained from the reservoirs.
5.1. Carbon dioxide gas solubility
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CARBON DIOXIDE ENHANCED OIL RECOVERY
From the figure below w can see the effect of the carbon dioxuide saturation pressure on
the gas solubilityfor the tested oil samples. The solubility if carbon dioxide gas increases
significantly as the gas saturation pressure increases. The incerase in the gas solubility is also
goes up as the temperetaure incerases. This is a s aresult of carbon having a fretare solubility
than all the other convetional gases like methane and nitrigen. The higher dissolution conytents
of the gas increses the natutal drube energy thatis available for the production of the rservoir.
Figure 1: Carbon dioxide gas solubility against the gas saturation pressure (Mansoura, et al.,
2019).
5.2. Carbon dioxide oil viscosity
As visible in the figure below the solid lines represents a sample which assist clarify the
variation that exist in the carbon dioxide oil viscosity with different levels of carbon dioxide. the
figure can be used to conclude that addition of the gas has a reducing effect on the oil sample’s
viscosity. This is because carbon dioxide has a relatively lower viscosity when compared to the
crude oil. As the oil viscosity goes down the total mobility ratio between reservoir oil and the
displaced flued is improved. As a result, the recovery efficiency of the oil is impacted in a
positive way.
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CARBON DIOXIDE ENHANCED OIL RECOVERY
Figure 2: Carbon dioxide oil viscosity against CO2 saturation pressure (Mansoura, et al.,
2019).
5.3. The density of carbon dioxide
The lines in the figure do show that the density of carbon dioxide does increase as the
percentage of carbon dioxide goes up in a sample at a constant temperature. As the carbon
dioxide injection increases the mass of carbon dioxide also increase hence the increased ability
of the gas to extract hydrocarbon components from crude oil.
Figure 3: Carbon dioxide oil density vs carbon dioxide saturation pressure (Mansoura, et al.,
2019)
5.4. Swelling factor of carbon dioxide
12