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U. S. Behera and J. S. Sangwai
for enhanced oil recovery. In this method, fire is ignited in the subsurface with a
fire fed by continuous supply through the injection well. Finally, fire moves toward
the production well from the injection well. With the generation of huge heat in the
reservoir higher hydrocarbon compound decomposes to produce smaller ones which
result in increase in mobility due to mixing the vapor of lighter hydrocarbon with
the reservoir fluid and hence increases fluid flow.
4 Thermal Methods for Enhanced Oil Recovery
Some popular thermal methods have been adopted for heavy oil reservoirs for oil
production in which heat energy is introduced into the formation containing highly
viscous crude oil. These methods are divided into two types: (a) steam injection
methods; (b) in situ combustion methods. Steam injection is most common method
used for shallow heavy oil. Some of the examples of such reservoirs are in the San
Joaquin Valley of California or those that comprise the oil sands of Alberta, Canada.
In steam injection methods, steam is injected into the formation through the injection
well and is driven toward the oil to physically displace it. Steam floods require
continuity in the formation to allow steam to drive oil toward the production well. As
steam carry huge amount of heat along with it, the complex hydrocarbon molecule of
reservoir fluid decomposes producing numbers of lower hydrocarbons. Lowering the
viscosity of the reservoir fluid is due to mixing the vapor of lower hydrocarbon with
the reservoir fluid. The decreased viscosity helps to reduce the interfacial tension,
increase the permeability of oil and improves the reservoir seepage conditions. Steam
injection is usually more environmental friendly than other EOR methods. The steam
itself does not pose a great threat since it just condenses to water, which causes no
pollution.
Similarly, during in situ combustion process, significant amount of heat is generated in the reservoir leading to breaking of complex molecular compounds. In situ
combustion is basically injection of an oxidizing gas (air or oxygen-enriched air) to
generate heat by burning a portion of resident oil. Most of the oil is driven toward
the producers by a combination of the gas, steam, and water. This process is also
called fire flooding to describe the movement of a burning front (forward or reverse)
inside the reservoir. During the process, oil-wet surface of the rocks changes into
water-wet and viscosity of the oil reduced drastically. The decrease in viscosity of
the oil increases the probability of higher oil production. Thermally enhanced oil
recovery method is the best technique for unlocking the heavy oil formation (Sahar
et al. 2018).
The result of recent experiments (Sahar et al. 2018) reported that the application
of iron oxide (Fe 2 O 3 ) nanoparticles (2 wt%) with distilled water as a dispersion
medium on heavy oil reservoir has decreased the viscosity of the oil and increased
the oil recovery. The results also revealed that heavy oil recovery with application
of iron oxide nanofluid also known as magnetic fluid was achieved up to 68.41%.
The investigation report revealed that in the presence of Fe 2 O 3 NPs (30 nm), oil
U. S. Behera and J. S. Sangwai
for enhanced oil recovery. In this method, fire is ignited in the subsurface with a
fire fed by continuous supply through the injection well. Finally, fire moves toward
the production well from the injection well. With the generation of huge heat in the
reservoir higher hydrocarbon compound decomposes to produce smaller ones which
result in increase in mobility due to mixing the vapor of lighter hydrocarbon with
the reservoir fluid and hence increases fluid flow.
4 Thermal Methods for Enhanced Oil Recovery
Some popular thermal methods have been adopted for heavy oil reservoirs for oil
production in which heat energy is introduced into the formation containing highly
viscous crude oil. These methods are divided into two types: (a) steam injection
methods; (b) in situ combustion methods. Steam injection is most common method
used for shallow heavy oil. Some of the examples of such reservoirs are in the San
Joaquin Valley of California or those that comprise the oil sands of Alberta, Canada.
In steam injection methods, steam is injected into the formation through the injection
well and is driven toward the oil to physically displace it. Steam floods require
continuity in the formation to allow steam to drive oil toward the production well. As
steam carry huge amount of heat along with it, the complex hydrocarbon molecule of
reservoir fluid decomposes producing numbers of lower hydrocarbons. Lowering the
viscosity of the reservoir fluid is due to mixing the vapor of lower hydrocarbon with
the reservoir fluid. The decreased viscosity helps to reduce the interfacial tension,
increase the permeability of oil and improves the reservoir seepage conditions. Steam
injection is usually more environmental friendly than other EOR methods. The steam
itself does not pose a great threat since it just condenses to water, which causes no
pollution.
Similarly, during in situ combustion process, significant amount of heat is generated in the reservoir leading to breaking of complex molecular compounds. In situ
combustion is basically injection of an oxidizing gas (air or oxygen-enriched air) to
generate heat by burning a portion of resident oil. Most of the oil is driven toward
the producers by a combination of the gas, steam, and water. This process is also
called fire flooding to describe the movement of a burning front (forward or reverse)
inside the reservoir. During the process, oil-wet surface of the rocks changes into
water-wet and viscosity of the oil reduced drastically. The decrease in viscosity of
the oil increases the probability of higher oil production. Thermally enhanced oil
recovery method is the best technique for unlocking the heavy oil formation (Sahar
et al. 2018).
The result of recent experiments (Sahar et al. 2018) reported that the application
of iron oxide (Fe 2 O 3 ) nanoparticles (2 wt%) with distilled water as a dispersion
medium on heavy oil reservoir has decreased the viscosity of the oil and increased
the oil recovery. The results also revealed that heavy oil recovery with application
of iron oxide nanofluid also known as magnetic fluid was achieved up to 68.41%.
The investigation report revealed that in the presence of Fe 2 O 3 NPs (30 nm), oil