![Oil & gas injection well](https://upload.wikimedia.org/wikipedia/commons/7/76/Oil_%26_gas_injection_well.jpg)
Enhanced oil recovery (abbreviated EOR), also called tertiary recovery, is the extraction of
crude oil from an
oil field that cannot be extracted otherwise. EOR can extract 30% to 60% or more of a reservoir's oil,
compared to 20% to 40% using
primary and
secondary recovery
Petroleum is a fossil fuel that can be drawn from beneath the earth's surface. Reservoirs of petroleum was formed through the mixture of plants, algae, and sediments in shallow seas under high pressure. Petroleum is mostly recovered from oil dri ...
. According to the US Department of Energy,
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
and
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
are injected along with one of three EOR techniques: thermal injection, gas injection, and chemical injection.
More advanced, speculative EOR techniques are sometimes called quaternary recovery.
Methods
There are three primary techniques of EOR: gas injection, thermal injection, and chemical injection. Gas injection, which uses gases such as
natural gas
Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbo ...
,
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
, or
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
(CO
2), accounts for nearly 60 percent of EOR production in the United States.
Thermal injection, which involves the introduction of
heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is ...
, accounts for 40 percent of EOR production in the United States, with most of it occurring in California.
Chemical injection, which can involve the use of long-chained molecules called
polymer
A polymer (; Greek '' poly-'', "many" + ''-mer'', "part")
is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...
s to increase the effectiveness of waterfloods, accounts for about one percent of EOR production in the United States.
In 2013, a technique called
Plasma-Pulse technology was introduced into the United States from Russia. This technique can result in another 50 percent of improvement in existing well production.
Gas injection
Gas injection or miscible flooding is presently the most-commonly used approach in enhanced oil recovery. Miscible flooding is a general term for injection processes that introduce miscible gases into the reservoir. A miscible displacement process maintains reservoir pressure and improves oil displacement because the interfacial tension between oil and gas is reduced. This refers to removing the interface between the two interacting fluids. This allows for total displacement efficiency.
Gases used include CO
2, natural gas or nitrogen. The fluid most commonly used for miscible displacement is carbon dioxide because it reduces the oil
viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
and is less expensive than
liquefied petroleum gas.
Oil displacement by
carbon dioxide injection relies on the phase behavior of the mixtures of that gas and the crude, which are strongly dependent on reservoir temperature, pressure and crude oil composition.
Thermal injection
![Steam eor1](https://upload.wikimedia.org/wikipedia/commons/5/5a/Steam_eor1.jpg)
In this approach, various methods are used to heat the crude oil in the formation to reduce its viscosity and/or vaporize part of the oil and thus decrease the mobility ratio. The increased heat reduces the surface tension and increases the permeability of the oil. The heated oil may also vaporize and then condense forming improved oil. Methods include
cyclic steam injection, steam flooding and combustion. These methods improve the sweep efficiency and the displacement efficiency. Steam injection has been used commercially since the 1960s in California fields. In 2011
solar thermal enhanced oil recovery
Solar thermal enhanced oil recovery (abbreviated solar EOR) is a form of thermal enhanced oil recovery (EOR), a technique applied by oil producers to extract more oil from maturing oil fields. Solar EOR uses solar thermal arrays to concentrate the ...
projects were started in California and
Oman
Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of ...
, this method is similar to thermal EOR but uses a solar array to produce the steam.
In July 2015,
Petroleum Development Oman
Petroleum Development Oman (PDO) is the leading exploration and production company in the Sultanate of Oman. The Company delivers the majority of the country's crude oil production and natural gas supply. The company is owned by the Government of ...
and
GlassPoint Solar announced that they signed a $600 million agreement to build a 1 GWth solar field on the Amal oilfield. The project, named
Miraah
Miraah is a solar thermal energy plant that is under construction in Oman for the production of steam for solar thermal enhanced oil recovery. In July 2015, Petroleum Development Oman and GlassPoint Solar announced that they signed a $600 milli ...
, will be the world's largest solar field measured by peak thermal capacity.
In November 2017, GlassPoint and Petroleum Development Oman (PDO) completed construction on the first block of the Miraah solar plant safely on schedule and on budget, and successfully delivered steam to the Amal West oilfield.
Also in November 2017, GlassPoint and
Aera Energy
Aera Energy LLC (or simply Aera) is a natural gas, oil exploration and production company started as a joint venture between Shell plc (through Shell USA) and Mobil (which later merged to form ExxonMobil). Headquartered in Bakersfield, Californ ...
announced a joint project to create California's largest solar EOR field at the
South Belridge Oil Field
The South Belridge Oil Field is a large oil field in northwestern Kern County, San Joaquin Valley, California, about forty miles west of Bakersfield. Discovered in 1911, and having a cumulative production of over of oil at the end of 2008, i ...
, near
Bakersfield, California. The facility is projected to produce approximately 12 million barrels of steam per year through a 850MW thermal solar steam generator. It will also cut carbon emissions from the facility by 376,000 metric tons per year.
Steam flooding
Steam flooding (see sketch) is one means of introducing heat to the reservoir by pumping steam into the well with a pattern similar to that of water injection. Eventually the steam condenses to hot water; in the steam zone the oil evaporates, and in the hot water zone the oil expands. As a result, the oil expands, the viscosity drops, and the permeability increases. To ensure success the process has to be cyclical. This is the principal enhanced oil recovery program in use today.
* ''
Solar EOR'' is a form of steam flooding that uses
solar arrays
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and c ...
to concentrate the sun's energy to heat water and generate steam. Solar EOR is proving to be a viable alternative to gas-fired steam production for the
oil industry
The petroleum industry, also known as the oil industry or the oil patch, includes the global processes of exploration, extraction, refining, transportation (often by oil tankers and pipelines), and marketing of petroleum products. The larges ...
.
Fire flooding
Fire flooding works best when the oil saturation and porosity are high. Combustion generates the heat within the reservoir itself. Continuous injection of air or other gas mixture with high oxygen content will maintain the flame front. As the fire burns, it moves through the reservoir toward production wells. Heat from the fire reduces oil viscosity and helps vaporize reservoir water to steam. The steam, hot water, combustion gas and a bank of distilled solvent all act to drive oil in front of the fire toward production wells.
There are three methods of combustion: Dry forward, reverse and wet combustion. Dry forward uses an igniter to set fire to the oil. As the fire progresses the oil is pushed away from the fire toward the producing well. In reverse the air injection and the ignition occur from opposite directions. In wet combustion water is injected just behind the front and turned into steam by the hot rock. This quenches the fire and spreads the heat more evenly.
Chemical injection
The injection of various chemicals, usually as dilute solutions, have been used to aid mobility and the reduction in
surface tension.
Injection of
alkaline or
caustic
Caustic most commonly refers to:
* Causticity, a property of various corrosive substances
** Sodium hydroxide, sometimes called ''caustic soda''
** Potassium hydroxide, sometimes called ''caustic potash''
** Calcium oxide, sometimes called ''caus ...
solutions into reservoirs with oil that have
organic acids naturally occurring in the oil will result in the production of
soap
Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are use ...
that may lower the
interfacial tension enough to increase production. Injection of a dilute solution of a
water-soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solub ...
polymer to increase the viscosity of the injected water can increase the amount of oil recovered in some formations. Dilute solutions of
surfactants such as petroleum
sulfonate
In organosulfur chemistry, a sulfonate is a salt or ester of a sulfonic acid. It contains the functional group , where R is an organic group. Sulfonates are the conjugate bases of sulfonic acids. Sulfonates are generally stable in water, non-o ...
s or
biosurfactant Biosurfactant usually refers to surfactants of microbial origin. Most of the biosurfactants produced by microbes are synthesized extracellularly and many microbes are known to produce biosurfactants in large relative quantities. Some are of commerc ...
s such as
rhamnolipid
Rhamnolipids are a class of glycolipid produced by ''Pseudomonas aeruginosa'', amongst other organisms, frequently cited as bacterial surfactants. They have a glycosyl head group, in this case a rhamnose moiety, and a 3-(hydroxyalkanoyloxy)alkanoi ...
s may be injected to lower the
interfacial tension or
capillary pressure that impedes oil droplets from moving through a reservoir, this is analyzed in terms of the
bond number
Bond or bonds may refer to:
Common meanings
* Bond (finance), a type of debt security
* Bail bond, a commercial third-party guarantor of surety bonds in the United States
* Chemical bond, the attraction of atoms, ions or molecules to form chemical ...
, relating capillary forces to gravitational ones. Special formulations of oil, water and surfactant,
microemulsion Microemulsions are clear, thermodynamically stable isotropic liquid mixtures of oil, water and surfactant, frequently in combination with a cosurfactant. The aqueous phase may contain salt(s) and/or other ingredients, and the "oil" may actually be ...
s, can be particularly effective in reducing interfacial tension. Application of these methods is usually limited by the cost of the chemicals and their adsorption and loss onto the rock of the oil containing formation. In all of these methods the chemicals are injected into several wells and the production occurs in other nearby wells.
Polymer flooding
Polymer flooding consists in mixing long chain polymer molecules with the injected water in order to increase the water viscosity. This method improves the vertical and areal sweep efficiency as a consequence of improving the water/oil mobility ratio.
Surfactants may be used in conjunction with polymers and
hyperbranched polyglycerols; they decrease the interfacial tension between the oil and water.
This reduces the residual oil saturation and improves the macroscopic efficiency of the process.
Primary surfactants usually have co-surfactants, activity boosters, and co-solvents added to them to improve stability of the formulation.
Caustic flooding is the addition of
sodium hydroxide to injection water. It does this by lowering the surface tension, reversing the rock wettability,
emulsification
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Altho ...
of the oil, mobilization of the oil and helps in drawing the oil out of the rock.
Low salinity nanofluids
EOR processes can be enhanced with nanoparticles in three ways: nanocatalysts, nanofluids, and nanoemulsions. Nanofluids are base fluids that contain nanoparticles in colloidal suspensions. Nanofluids perform many functions in EOR of oil fields, including pore disjoining pressure, channel plugging, interfacial tension reduction, mobility ratio, wettability alteration, and asphaltene precipitation prevention. Nanofluids facilitates disjoining pressure to remove sediment entrapped oil via aggregation at the interface. Alternatively, wettability alteration and interfacial surface tension reduction are other alternative mechanism of EOR.
Microbial injection
Microbial injection is part of
microbial enhanced oil recovery
Microbial enhanced oil recovery (MEOR) is a biological based technology consisting in manipulating function or structure, or both, of microbial environments existing in Petroleum reservoir, oil reservoirs. The ultimate aim of MEOR is to improve the ...
and is rarely used because of its higher cost and because the
development
Development or developing may refer to:
Arts
*Development hell, when a project is stuck in development
*Filmmaking, development phase, including finance and budgeting
*Development (music), the process thematic material is reshaped
* Photograph ...
is not widely accepted. These
microbes function either by partially digesting long
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...
molecules, by generating
biosurfactant Biosurfactant usually refers to surfactants of microbial origin. Most of the biosurfactants produced by microbes are synthesized extracellularly and many microbes are known to produce biosurfactants in large relative quantities. Some are of commerc ...
s, or by emitting carbon dioxide (which then functions as described in
Gas injection above).
Three approaches have been used to achieve microbial injection. In the first approach, bacterial cultures mixed with a food source (a carbohydrate such as
molasses is commonly used) are injected into the oil field. In the second approach, used since 1985, nutrients are injected into the ground to nurture existing microbial bodies; these nutrients cause the bacteria to increase production of the natural surfactants they normally use to metabolize crude oil underground. After the injected nutrients are consumed, the microbes go into near-shutdown mode, their exteriors become
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are ...
, and they migrate to the oil-water interface area, where they cause oil droplets to form from the larger oil mass, making the droplets more likely to migrate to the wellhead. This approach has been used in oilfields near the
Four Corners and in the
Beverly Hills Oil Field
The Beverly Hills Oil Field is a large and currently active oil field underneath part of the US cities of Beverly Hills, California, and portions of the adjacent city of Los Angeles. Discovered in 1900, and with a cumulative production of over 150 ...
in
Beverly Hills, California.
The third approach is used to address the problem of
paraffin wax
Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to ...
components of the crude oil, which tend to precipitate as the crude flows to the surface, since the Earth's surface is considerably cooler than the petroleum deposits (a temperature drop of 9–10–14 °C per thousand feet of depth is usual).
Liquid carbon dioxide superfluids
Carbon dioxide (CO
2) is particularly effective in reservoirs deeper than 2,000 ft., where CO
2 will be in a
supercritical state. In high pressure applications with lighter oils, CO
2 is miscible with the oil, with resultant swelling of the oil, and reduction in viscosity, and possibly also with a reduction in the surface tension with the reservoir rock. In the case of low pressure reservoirs or heavy oils, CO
2 will form an immiscible fluid, or will only partially mix with the oil. Some oil swelling may occur, and oil viscosity can still be significantly reduced.
In these applications, between one-half and two-thirds of the injected CO
2 returns with the produced oil and is usually re-injected into the reservoir to minimize operating costs. The remainder is trapped in the oil reservoir by various means. Carbon dioxide as a solvent has the benefit of being more economical than other similarly miscible fluids such as
propane and
butane.
Water-alternating-gas (WAG)
Water-alternating-gas (WAG) injection is another technique employed in EOR. Water is used in addition to carbon dioxide. A saline solution is used here so that carbonate formations in oil wells are not disturbed. Water and carbon dioxide are injected into the oil well for larger recovery, as they typically have low miscibility with oil. Use of both water and carbon dioxide also lowers the mobility of carbon dioxide, making the gas more effective at displacing the oil in the well.
According to a study done by Kovscek, using small slugs of both carbon dioxide and water allows for quick recovery of the oil.
Additionally, in a study done by Dang in 2014, using water with a lower salinity allows for greater oil removal, and greater geochemical interactions.
Plasma-pulse
Plasma-pulse technology is a technique used in the US as of 2013. The technology originated in the Russian Federation at the
St. Petersburg State Mining University with funding and assistance from the
Skolkovo Innovation Center
The Skolkovo Innovation Center is a high technology business area at Mozhaysky District in Moscow, Russia. Although historically Russia has been successful with development of science and technology, its lack of entrepreneurial spirit led to g ...
.
The development team in Russia and deployment teams across Russia, Europe and now the USA have tested this technology in vertical wells with nearly 90% of wells showing positive effects.
The Plasma-Pulse Oil Well EOR uses low energy emissions to create the same effect that many other technologies can produce except without negative ecological impact. In nearly every case the volume of water pulled with the oil is actually reduced from pre-EOR treatment instead of increased. Current clients and users of the new technology include
ConocoPhillips,
ONGC,
Gazprom,
Rosneft and
Lukoil.
It is based in the same technology as the Russian
pulsed plasma thruster
A pulsed plasma thruster (PPT), also known as a plasma jet engine, is a form of electric spacecraft propulsion. PPTs are generally considered the simplest form of electric spacecraft propulsion and were the first form of electric propulsion to be ...
which was used on two space ships and is currently being advanced for use in horizontal wells.
Economic costs and benefits
Adding oil recovery methods adds to the cost of oil—in the case of CO
2 typically between 0.5–8.0 US$ per tonne of CO
2. The increased extraction of oil on the other hand, is an economic benefit with the revenue depending on prevailing
oil prices. Onshore EOR has paid in the range of a net 10–16 US$ per tonne of CO
2 injected for oil prices of 15–20 US$/
barrel. Prevailing prices depend on many factors but can determine the economic suitability of any procedure, with more procedures and more expensive procedures being economically viable at higher prices. Example: With oil prices at around 90 US$/barrel, the economic benefit is about 70 US$ per tonne CO
2. The
U.S. Department of Energy estimates that 20 billion tons of captured CO
2 could produce 67 billion barrels of economically recoverable oil.
The oil and gas industry argues that the use of captured,
anthropogenic carbon dioxide, derived from the exploitation of
lignite coal reserves, to drive
electric power generation
Electricity generation is the process of generating electric power from sources of primary energy. For utilities in the electric power industry, it is the stage prior to its delivery (transmission, distribution, etc.) to end users or its storag ...
and support EOR from existing and future oil and gas wells offers a multifaceted solution to U.S. energy, environmental, and economic challenges.
[ There is no doubt that ]coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when ...
and oil resources are finite. The U.S. is in a strong position to leverage such traditional energy sources to supply future power needs while other sources are being explored and developed.[ For the ]coal industry
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal is formed when de ...
, CO2 EOR creates a market for coal gasification byproducts and reduces the costs associated with carbon sequestration and storage.
From 1986 to 2008, the quote oil production deriving from EOR has increased from 0.3% to 5%, thanks to an increasing oil demand and a reduction of oil supply.
EOR projects with CO2 from carbon capture
Boundary Dam Power Station, Canada
SaskPower
Saskatchewan Power Corporation, operating as SaskPower, is the principal electric utility in Saskatchewan, Canada. Established in 1929 by the provincial government, it serves more than 538,000 customers and manages over $11.8 billion in assets. Sa ...
's Boundary Dam Power Station
Boundary Dam Power Station is the largest coal fired station owned by SaskPower, located near Estevan, Saskatchewan, Canada.
Description
The Boundary Dam Power Station consists of two 62 net MW units (commissioned in 1959, shut down and decommis ...
project retrofitted its coal-fired power station in 2014 with carbon capture and sequestration (CCS) technology. The plant will capture 1 million tonnes of annually, which it sold to Cenovus Energy for enhanced oil recovery at its Weyburn Oil Field, prior to the sale of Cenovus's Saskatchewan assets in 2017 to Whitecap Resources. The project is expected to inject a net 18 million ton CO2 and recover an additional of oil, extending the life of the oil field by 25 years. There is a projected 26+ million tonnes (net of production) of to be stored in Weyburn, plus another 8.5 million tonnes (net of production) stored at the Weyburn-Midale Carbon Dioxide Project
The Weyburn-Midale Carbon Dioxide Project (or IEA GHG Weyburn-Midale Monitoring and Storage Project) is, as of 2008, the world's largest carbon capture and storage project.Allan Casey, ''Carbon Cemetery'', Canadian Geographic Magazine, Jan/Feb 2 ...
, resulting in a net reduction in atmospheric CO2 by CO2 storage in the oilfield. That's the equivalent of taking nearly 7 million cars off the road for a year. Since CO2 injection began in late 2000, the EOR project has performed largely as predicted. Currently, some 1600 m3 (10,063 barrels) per day of incremental oil is being produced from the field.
Petra Nova, United States
The Petra Nova
The Petra Nova project is a coal-energy-sector/clean-energy project designed to reduce carbon emissions from one of the boilers of a Fossil fuel power station, coal burning power plant in Thompsons, Texas. It is a multi-million dollar project take ...
project uses post-combustion amine absorption to capture some of the carbon dioxide emissions from one of the boilers at the W.A Parish power plant in Texas, and transports it by pipeline to the West Ranch oil field for use in enhanced oil recovery.
Kemper Project, United States (canceled)
Mississippi Power
Mississippi Power (NYSEMPJ is an investor-owned electric utility and a wholly owned subsidiary of Atlanta-based Southern Company. Mississippi Power Company (MPC) is headquartered in Gulfport, Mississippi.
Mississippi Power has 1,253 employees an ...
's Kemper County energy facility, or Kemper Project
The Kemper Project, also called the Kemper County energy facility or Plant Ratcliffe, is a natural gas-fired electrical generating station currently under construction in Kemper County, Mississippi. Mississippi Power, a subsidiary of Southern Co ...
, was to have been a first-of-its-kind plant in the U.S. that was expected to be online in 2015. Its coal gasification component has since been canceled, and the plant has been converted to a conventional natural gas combined cycle power plant without carbon capture. The Southern Company
Southern Company is an American gas and electric utility holding company based in the southern United States. It is headquartered in Atlanta, Georgia, with executive offices also located in Birmingham, Alabama. The company is the second largest ...
subsidiary worked with the U.S. Department of Energy and other partners with the intention to develop cleaner, less expensive, more reliable methods for producing electricity with coal that also support EOR production. The gasification technology was designated to fuel the integrated gasification combined cycle
integrated gasification combined cycle (IGCC) is a technology using a high pressure gasifier to turn coal and other carbon based fuels into pressurized gas—synthesis gas (syngas). It can then remove impurities from the syngas prior to the electr ...
power plant.[ Additionally, the unique location of the Kemper Project, and its proximity to ]oil reserves
An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...
, made it an ideal candidate for enhanced oil recovery.
Weyburn-Midale, Canada
In 2000, Saskatchewan
Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...
's Weyburn-Midale oil field began to employ EOR as a method of oil extraction. In 2008, the oilfield became the world's largest storage site of carbon dioxide. The Carbon Dioxide comes through 320 km of pipeline from Dakota Gasification facility. It is estimated that the EOR project will store around 20 million tons of Carbon Dioxide, generate about 130 million barrels of oil, and extend the life of the field by over two decades. The site is also notable as it hosted a study on the effects of EOR on nearby seismic activity.
CO2 EOR in the United States
The United States has been using CO2 EOR for several decades. For over 30 years, oil fields in the Permian Basin have implemented EOR using naturally sourced from New Mexico and Colorado.[Logan, Jeffrey and Venezia, John (2007]
"CO2-Enhanced Oil Recovery."
Excerpt from a WRI Policy Note, "Weighing U.S.
Energy Options: The WRI Bubble Chart." World Resources Institute, Washington, DC. The Department of Energy (DOE) has estimated that full use of 'next generation' CO2-EOR in United States could generate an additional of recoverable oil resources. Developing this potential would depend on the availability of commercial CO2 in large volumes, which could be made possible by widespread use of carbon capture and storage. For comparison, the total undeveloped US domestic oil resources still in the ground total more than , most of it remaining unrecoverable. The DOE estimates that if the EOR potential were to be fully realized, state and local treasuries would gain $280 billion in revenues from future royalties, severance tax
Severance taxes are taxes imposed on the removal of natural resources within a taxing jurisdiction. Severance taxes are most commonly imposed in oil producing states within the United States. Resources that typically incur severance taxes when e ...
es, and state income taxes on oil production, aside from other economic benefits.
The main barrier to taking further advantage of CO2 EOR in the United States has been an insufficient supply of affordable CO2. Currently, there is a cost gap between what an oilfield operation could afford to pay for CO2 under normal market conditions and the cost to capture and transport CO2 from power plants and industrial sources, so most CO2 comes from natural sources. However, using CO2 from power plants or industrial sources could reduce the carbon footprint (if the CO2 is stored underground). For some industrial sources, such as natural gas processing or fertilizer and ethanol production, the cost gap is small (potentially $10–20/tonne CO2). For other man-made sources of CO2, including power generation and a variety of industrial processes, capture costs are greater, and the cost gap becomes much larger (potentially $30–50/tonne CO2). The Enhanced Oil Recovery Initiative has brought together leaders from industry, the environmental community, labor, and state governments to advance CO2 EOR in the United States and close the price gap.
In the US, regulations can both assist and slow down the development of EOR for use in carbon capture & utilization, as well as general oil production. One of the primary regulations governing EOR is the Safe Drinking Water Act
The Safe Drinking Water Act (SDWA) is the principal federal law in the United States intended to ensure safe drinking water for the public. Pursuant to the act, the Environmental Protection Agency (EPA) is required to set standards for drinking wa ...
of 1974 (SDWA), which gives most of the regulatory power over EOR and similar oil recovery operations to the EPA
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
. The agency in turn delegated some of this power to its own Underground Injection Control Program, and much of the rest of this regulatory authority to state and tribal governments, making much of EOR regulation a localized affair under the minimum requirements of the SDWA. The EPA then collects information from these local governments and individual wells to ensure they follow overall federal regulation, such as the Clean Air Act, which dictates reporting guidelines for any Carbon Dioxide sequestration operations. Beyond the atmospheric concerns, most of these federal guidelines are to ensure that the Carbon Dioxide injection causes no major damage to America's waterways. Overall, the locality of EOR regulation can make EOR projects more difficult, as different standards in different regions can slow down construction and force separate approaches to utilize the same technology.
In February 2018, Congress passed and the President signed an expansion of the carbon capture tax credits defined in section 45Q of the IRS' Internal Revenue code. Previously, these credits were limited to $10/ton and capped at a total of 75 million tons. Under the expansion, carbon capture and utilization projects like EOR will be eligible for a tax credit of $35/ton, and sequestration projects will receive a $50/ton credit. The expanded tax credit would be available for 12 years to any plant constructed by 2024, with no volume cap. If successful, these credits "could help sequester between 200 million and 2.2 billion metric tons of carbon dioxide" and bring down carbon capture and sequestration costs from a currently estimated $60/ton at Petra Nova to as low as $10/ton.
Environmental impacts
Enhanced oil recovery wells typically pump large quantities of produced water
Produced water is a term used in the oil industry or geothermal industry to describe water that is produced as a byproduct during the extraction of oil and natural gas, or used as a medium for heat extraction. Produced water is the kind of brackis ...
to the surface. This water contains brine and may also contain toxic
Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...
heavy metals and radioactive substances. This can be very damaging to drinking water
Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...
sources and the environment generally if not properly controlled. Disposal wells are used to prevent surface contamination of soil and water by injecting the produced water deep underground.
In the United States, injection well
An injection well is a device that places fluid deep underground into porous rock formations, such as sandstone or limestone, or into or below the shallow soil layer. The fluid may be water, wastewater, brine (salt water), or water mixed with indus ...
activity is regulated by the United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...
(EPA) and state governments under the Safe Drinking Water Act
The Safe Drinking Water Act (SDWA) is the principal federal law in the United States intended to ensure safe drinking water for the public. Pursuant to the act, the Environmental Protection Agency (EPA) is required to set standards for drinking wa ...
. EPA has issued Underground Injection Control (UIC) regulations in order to protect drinking water sources. Enhanced oil recovery wells are regulated as "Class II" wells by the EPA. The regulations require well operators to reinject the brine used for recovery deep underground in Class II disposal wells.
See also
* Gas reinjection
Gas reinjection is the reinjection of natural gas into an underground reservoir, typically one already containing both natural gas and crude oil, in order to increase the pressure within the reservoir and thus induce the flow of crude oil or else ...
* Steam assisted gravity drainage
* Water injection (oil production)
In the oil industry, waterflooding or water injection is where water is injected into the oil reservoir, to maintain the pressure (also known as voidage replacement), or to drive oil towards the wells, and thereby increase production. Water inje ...
* Wikiversity:Enhanced oil recovery
References
IPCC Special Report on Carbon dioxide Capture and Storage
Chapter 5, Underground geological storage. Intergovernmental Panel on Climate Change (IPCC), 2005.
ttps://web.archive.org/web/20090425063318/http://www.fossil.energy.gov/programs/oilgas/publications/eor_co2/Undeveloped_Oil_Document.pdf pdf// US Department of Energy, analysis of EOR potential. Game Changer Improvements Could Dramatically Increase Domestic Oil Resource Recovery. An analysis by Advanced Resources International, Arlington, VA, for the U.S. Department of Energy's Office of Fossil Energy. Advanced Resources International, February 2006. See als
press release
External links
Enhanced Oil Recovery Institute
– University of Wyoming
Licensable Technology: Particle Stabilized Emulsions of Carbon Dioxide & Water for Enhanced Oil Recovery & Extraction Processes
– Massachusetts Technology Portal
Oilfield Glossary: Enhanced Oil Recovery
– Schlumberger, Ltd.
Center for Petroleum and Geosystems Engineering
– University of Texas at Austin
Polymer Flooding, Reservoir Sweep Improvement, New Mexico Tech
{{DEFAULTSORT:Enhanced Oil Recovery
Petroleum production