Flaring gas
Flaring gas refers to the practice of burning off excess natural gas that is released during the extraction of crude oil and other fossil fuels. This gas, often called casinghead or associated gas, is typically a mixture of methane and higher hydrocarbons. Flaring produces a bright fireball and has historically been used for safety reasons, particularly during well start-up and testing phases, or when drilling fluids become contaminated. Despite its longstanding use, flaring has come under scrutiny due to its environmental impacts, notably contributing to carbon dioxide emissions and other pollutants that can harm human health and the environment.
Globally, flaring has increased since the 1990s, driven by rising oil demand and extraction in remote areas, with significant flaring occurring in countries such as Russia, Nigeria, and Iran. Efforts to reduce flaring include the Global Gas Flaring Reduction Program, which promotes regulatory policies and encourages the utilization of associated gas for energy production. Alternatives to flaring, such as gas reinjection or conversion into liquid fuels, are being explored to mitigate its environmental impact and provide economic benefits to local communities. As regulations tighten, particularly in places like the United States, a shift toward more sustainable practices in gas management is gaining momentum.
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Flaring gas
Summary: The traditional practice of flaring natural gas at oil production sites is giving way to more environmentally sound measures that also benefit local communities and markets.
Flaring is the open-air burning of natural gas resulting from production of crude oil or other fossil fuel sources such as oil sands, oil shale, or coal. Natural gas associated with an oil field is also called casinghead gas or associated gas, whereas nonassociated gas comes from an isolated natural gas field. Gas flares can be located at oil wells and ocean rigs, gas wells, refineries, landfills, natural gas plants, or chemical plants.
When oil is brought to the surface at an extraction site, the more volatile components bubble out of the liquid upon depressurization. The gas is a colorless and mostly odorless mixture of methane and up to 20 percent of higher hydrocarbons, primarily ethane. In a process that has been around for decades, excess gas is ignited, producing a bright fireball. Flaring is employed during well start-up and testing in order to provide data for the selection of proper equipment. Also, when drilling mud or fracturing liquids become contaminated with gas, flaring can be used to dispose of the volatile component.
Historically, flaring was permitted for safety reasons, since natural gas is easily ignited. Unless there was a market near the wellhead, gas was considered of little value and was cheaply disposed of by combustion. Moreover, the sight of a flare high above the ground signaled success in oil production.
A flaring device or stack consists of an elevated vertical metal pipe capped by a nozzle or burner tip. Gas is conveyed up the stack to the tip, where it exits and burns in the presence of oxygen in the air. When combustion is efficient, no smoke is produced. When combustion is inefficient because of poor air mixing, wind, or impurities, black smoke is produced. However, when an enclosed ground flare design is employed, the flame is confined within the stack, resulting in reduced smoke. Some flares are equipped with a safety release system that is activated in the event of a pressure buildup. When the flare is not in use, a pilot light may be kept burning at the tip so that any released gas will immediately be ignited; remote ignition is also an option.
There are several alternatives to gas flaring. Unwanted oil production gas (stranded gas), which has no market, is often injected back into wells to repressurize the producing formation. Stranded gas can also be made into liquid fuels such as synthetic gasoline, diesel, or jet fuel. When local gas markets exist, the cost of building the necessary pipelines and related infrastructure may be worthwhile.
Globally, oil industry flaring has increased since the 1990s, in part because of increased demand for oil and the fact that oil extraction is now taking place in more remote locations. The World Bank estimates that flares burn 492 billion cubic feet (150 billion cubic meters) of natural gas annually. The top 10 flaring countries are Russia, Nigeria, Iran, Iraq, Kazakhstan, Algeria, Angola, Libya, Saudi Arabia, and Qatar. The United States has several flaring sites but makes use of more than 99 percent of gas from oil production.
Flaring involves a chemical transformation that produces carbon dioxide (CO2), water vapor, and energy. Around 400 million tons of CO2 are released into the atmosphere every year at flaring installations. According to the World Bank, flaring accounts for 2 percent of global carbon emissions annually. Besides CO2, flare emissions typically contain nitrogen and sulfur oxides, carbon monoxide, polyaromatic hydrocarbons, volatile organic compounds, and soot. The negative impacts of untreated flare stack emissions on human health can include skin and vision problems, cancer, and respiratory problems. Damage to crops and forests can also result from acid deposition due to stack emissions.
In 2007, the National Oceanic and Atmospheric Administration began using satellite imagery for estimating global volumes of flare gas. The technique is based on the detection of nighttime light pollution, or points of light on Earth’s surface. Measurement of flare gas volumes also permits the calculation of CO2 emissions.
The Global Gas Flaring Reduction Program (GGFR) is a public-private partnership launched by the World Bank in 2002. This program aids countries striving to establish regulatory policies and meet flared-out targets; it also promotes the commercialization of associated gas. Flaring reduction projects are currently under way in high-impact regions such as the Middle East and North Africa. Some countries have begun instituting fines if oil companies fail to come up with a workable flaring reduction plan. Another aim of the GGFR is to alleviate poverty by encouraging use of available gas as a source of fuel for heating and electricity generation.
The benefits of reduced flaring include decreased local air and ground pollution and the availability of a fuel source to power local industry and power plants. Hurdles to flaring reduction include the need to develop effective regulations, prudent financing, and flexible fuel choices. Regions facing the biggest challenges to reduction are West Africa, south and east Asia, Latin America, and transition economies such as Russia and China. In 2024, the US Interior Department's Bureau of Land Management issued a final rule to curb methane leaks from oil and gas drilling on federal and tribal lands. Part of the rule tightened to the limits on gas flaring.
Bibliography
Daly, Matthew. "Interior Department Rule Aims to Crack Down on Methane Leaks from Oil, Gas Drilling on Public Lands." PBS, 27 Mar. 2024, www.pbs.org/newshour/politics/interior-department-rule-aims-to-crack-down-on-methane-leaks-from-oil-gas-drilling-on-public-lands. Accessed 1 Aug. 2024.
National Oceanic and Atmospheric Administration. “Global Gas Flaring Estimates.” http://www.ngdc.noaa.gov/dmsp/interest/gas‗flares.html.
Sadek, Nicole, Zola Tunio, and Sarah Hunt. "Oil and Gas Companies ‘Flare’ or ‘Vent’ Excess Natural Gas. It’s Like Burning Money—And It’s Bad for the Environment." Inside Climate News, 25 Feb. 2022, insideclimatenews.org/news/25022022/flaring-venting-natural-gas-economics/. Accessed 1 Aug. 2024.
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Suykens, C. “Gas Flaring in Developing Countries: Need for Kyoto Mechanisms or Sectoral Crediting Mechanisms?” Carbon and Climate Law Review 4, no. 1 (2010).
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