Injection well
An injection well is a device that places fluid deep underground into
Definition
The
Applications
This section needs expansion. You can help by adding to it. (April 2015) |
Injection wells are used for many purposes.
Waste disposal
Treated wastewater can be injected into the ground between impermeable layers of rocks to avoid polluting surface waters. Injection wells are usually constructed of solid walled pipe to a deep elevation in order to prevent injectate from mixing with the surrounding environment.[1] Injection wells utilize the earth as a filter to treat the wastewater before it reaches the aquifer. This method of wastewater disposal also serves to spread the injectate over a wide area, further decreasing environmental impacts.[citation needed]
In the United States, there are about 800 deep injection waste disposal wells used by industries such as chemical manufacturers, petroleum refineries, food producers and municipal wastewater plants.[2] Most produced water generated by oil and gas extraction wells in the US is also disposed in deep injection wells.[3]
Critics of wastewater injection wells cite concerns about potential groundwater contamination. It is argued that the impacts of some injected wastes in groundwater is not fully understood, and that the science and regulatory agencies have not kept up with the rapid expansion of disposal practices in US, where there are over 680,000 wells as of 2012.[4]
Alternatives to injection wells include direct discharge of treated wastewater to receiving waters, conditioning of oil drilling and fracking produced water for reuse, utilization of treated water for irrigation or livestock watering, or processing of water at industrial wastewater treatment plants.[5] Direct discharge does not disperse the water over a wide area; the environmental impact is focused on a particular segment of a river and its downstream reaches or on a coastal water body. Extensive irrigation is not typical in areas where the produced water tends to be salty,[5] and this practice is often prohibitively expensive and requires ongoing maintenance and large electricity usage.[6]
Since the early 1990s,
Oil and gas production
Another use of injection wells is in natural gas and petroleum production. Steam, carbon dioxide, water, and other substances can be injected into an oil-producing unit in order to maintain reservoir pressure, heat the oil or lower its viscosity, allowing it to flow to a producing well nearby.[9]
Waste site remediation
Yet another use for injection wells is in
Aquifer recharge
Recently the option of
Surface runoff can also be recharged into dry wells, or simply barren wells that have been modified to functions as cisterns.[12] These hybrid stormwater management systems, called recharge wells, have the advantage of aquifer recharge and instantaneous supply of potable water at the same time. They can utilize existing infrastructure and require very little effort for the modification and operation. The activation can be as simple as inserting a polymer cover (foil) into the well shaft. Vertical pipes for conduction of the overflow to the bottom can enhance performance. The area around the well acts as funnel. If this area is maintained well the water will require little purification before it enters the cistern.[13]
Geothermal energy
Injection wells are used to tap geothermal energy in hot, porous rock formations below the surface by injecting fluids into the ground, which is heated in the ground, then extracted from adjacent wells as fluid, steam, or a combination of both. The heated steam and fluid can then be utilized to generate electricity or directly for geothermal heating.[14][15][16]
Regulatory requirements
In the United States, injection well activity is regulated by EPA and state governments under the Safe Drinking Water Act (SDWA).[1] The “State primary enforcement responsibility” section of the SDWA provides for States to submit their proposed UIC program to the EPA to request State assumption of primary enforcement responsibility. [17] Thirty-four states have been granted UIC primacy enforcement authority for Class I, II, III, IV and V wells.[18] For states without an approved UIC program, the EPA administrator prescribes a program to apply.[19] EPA has issued Underground Injection Control (UIC) regulations in order to protect drinking water sources.[20][21]
EPA regulations define six classes of injection wells. Class I wells are used for the injection of municipal and industrial wastes beneath underground sources of drinking water. Class II wells are used for the injection of fluids associated with oil and gas production, including waste from hydraulic fracturing. Class III wells are used for the injection of fluids used in mineral
Injection-induced earthquakes
A July 2013 study by US Geological Survey scientist William Ellsworth links earthquakes to wastewater injection sites. In the four years from 2010-2013 the number of earthquakes of magnitude 3.0 or greater in the central and eastern United States increased dramatically. After decades of a steady earthquake rate (average of 21 events/year), activity increased starting in 2001 and peaked at 188 earthquakes in 2011, including a record-breaking 5.7-magnitude earthquake near Prague, Oklahoma which was the strongest earthquake ever recorded in Oklahoma. USGS scientists have found that at some locations the increase in seismicity coincides with the injection of wastewater in deep disposal wells. Injection-induced earthquakes are thought to be caused by pressure changes due to excess fluid injected deep below the surface and are being dubbed “man-made” earthquakes.[24] On September 3, 2016, a 5.8-magnitude earthquake occurred near Pawnee, Oklahoma, followed by nine aftershocks between magnitudes 2.6 and 3.6 within three and one-half hours. The earthquake broke the previous record set five years earlier. Tremors were felt as far away as Memphis, Tennessee, and Gilbert, Arizona. Mary Fallin, the Oklahoma governor, declared a local emergency and shutdown orders for local disposal wells were ordered by the Oklahoma Corporation Commission.[25][26] Results of ongoing multi-year research on induced earthquakes by the United States Geological Survey (USGS) published in 2015 suggested that most of the significant earthquakes in Oklahoma, such as the 1952 magnitude 5.5 El Reno earthquake may have been induced by deep injection of waste water by the oil industry.[27]
Notes
- ^ a b c d e f "General Information About Injection Wells". Washington, DC: U.S. Environmental Protection Agency (EPA). 2020-04-20.
- ^ "Class I Industrial and Municipal Waste Disposal Wells". Underground Injection Control. EPA. 2016-09-06.
- ^ Summary of Input on Oil and Gas Extraction Wastewater Management Practices Under the Clean Water Act (Report). EPA. May 2020. p. 2. EPA 821-S-19-001.
- ^ Lustgarten, Abrahm (2012-06-21). "Injection Wells: The Poison Beneath Us". ProPublica. New York.
- ^ a b Erickson, Britt E. (2019-11-17). "Wastewater from fracking: Growing disposal challenge or untapped resource?". Chemical & Engineering News. Vol. 97, no. 45.
- ^ Martin, DL; Dorn, TW; Melvin, SR; Corr, AJ; Kranz, WL (February 2011). "Evaluation Energy Use for Pumping Irrigation Water" (PDF). Proceedings of the 23rd Annual Central Plains Irrigation Conference. Burlington, CO.
- ^ "Federal Judge Rejects Maui County Arguments on Lahaina Plant Violations". Civil Beat. 9 July 2014. Retrieved 2014-07-22.
- ^ Stohr, Greg (April 23, 2020). "Supreme Court Gives Environmentalists Partial Win on Water Law". Bloomberg News.
- ^ EPA. "Class II Oil and Gas Related Injection Wells." Updated 2015-10-08.
- ^ EPA. New York, NY (2003-04-17). "EPA Announces Cleanup Plan for Contaminated Soil and Ground Water at Central Islip Superfund Site." Example of use of ozonation wells for remediation in situ.
- ^ H2O magazine (2010-10-16). "Strategic reserve" by Anoop K Menon
- ^ H2O magazine (2011-05-03). "Recharging dry wells." Archived 2020-07-08 at the Wayback Machine by Nicol-André Berdellé
- ^ Prototype-Creation (2011-04-20). "Recharge wells and ASR." by Nicol-André Berdellé
- ^ "Geothermal Technologies Program: Tapping the Earth's energy to meet our heat and power needs" (PDF). U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. April 2004. Retrieved 2 June 2018.
- ^ Fitch, David; Matlick, Skip (2008). "Gold, silver and Other Metals in scale— Puna Geothermal Venture, Hawaii" (PDF). GRC Transactions. 32: 385–388. Archived from the original (PDF) on 1 November 2016. Retrieved 2 June 2018.
- ^ Gill, Andrea T. (2004). "Prospective Direct Use Enterprises in Kapoho, Hawaii" (PDF). Hawaii Dept. of Business, Economic Development and Tourism, Strategic Industries Division. Retrieved 2 June 2018.
- ^ 42 U.S.C. § 300h-1(b)
- ^ "Primary Enforcement Authority for the Underground Injection Control Program". EPA. 2019-04-15.
- ^ 42 U.S.C. § 300h-1(c)
- ^ EPA. "Underground Injection Control Regulations." Updated 2015-10-05.
- ^ EPA. (July 2001). "Technical Program Overview: Underground Injection Control Regulations." Document no. EPA 816-R-02-025.
- ^ "Class IV Shallow Hazardous and Radioactive Injection Wells". Underground Injection Control. EPA. 2016-09-06.
- ^ Philip K. Lau and Nadav C. Klugman (2022-06-22). ""CARBON CAPTURE, UTILIZATION, AND STORAGE: CLASS VI WELLS AND US STATE PRIMACY",".
- ^ USGS. "Man-Made Earthquakes Update" Archived 2014-03-29 at the Wayback Machine Updated January 17, 2014.
- ^ Record tying Oklahoma earthquake felt as far away as Arizona, Associated Press, Ken Miller, September 3, 2016. Retrieved 4 September 2016.
- ^ USGS calls for shut down of wells, governor declares emergency in wake of 5.6 quake in Oklahoma, Enid News & Eagle, Sally Asher & Violet Hassler, September 3, 2016. Retrieved 4 September 2016.
- ^ Hough, Susan E.; Page, Morgan (October 20, 2015). "A Century of Induced Earthquakes in Oklahoma?". U.S. Geological Survey. Retrieved November 8, 2015.
Several lines of evidence further suggest that most of the significant earthquakes in Oklahoma during the 20th century may also have been induced by oil production activities. Deep injection of waste water, now recognized to potentially induce earthquakes, in fact began in the state in the 1930s.
References
- US Army Environmental Center. Aberdeen Proving Ground, MD (2002). "Deep Well Injection." Remediation Technologies Screening Matrix and Reference Guide. 4th ed. Report no. SFIM-AEC-ET-CR-97053.