Published on 30th September 2022
Gas flaring refers to the combustion of excess natural gas under controlled conditions at oil wells and oil production and processing facilities. Generally, natural gas that is brought to the surface but cannot easily be used is “flared” (burned for disposal).
A majority of natural gas flaring is observed in upstream production areas where flaring is used during new well drilling and at refineries to prevent an explosive buildup of gases. The lack of direct market access and insufficient gas gathering and transportation infrastructure are other major reasons for ongoing flaring across global regions.
Gas flaring is considered a wasteful practice as the amount of natural gas burned can either be used productively or conserved for future use. Furthermore, natural gas flaring poses a serious threat to the environment globally because it creates noise and air pollution.
Instead of wasting gas through flaring each year, using the flared gas responsibly will benefit local communities, reduce an operator’s carbon footprint, and turn a wasted by-product into a revenue stream.
Often, flaring results from economic limitations but has potential for economic gain—improved utilization of associated gas enhances environmental stability and reduces lost market opportunities.
Overcoming the barriers to flaring reduction is essential for improving energy access and increasing energy security.
Why is gas flaring significant? How can we mitigate the challenges of gas flaring? What does the future hold for gas flaring? Keep reading to explore gas flaring in detail.
Also known as a “flare boom,” “flare pit,” “flare stack,” or “ground flare,” a gas flare is a gas combustion device (an elevated vertical chimney) used at places, such as:
While an air-assist mechanism at the tip of the “boom” or “stack” combines free air with the generated gases to improve combustion efficiency, a thermal oxidizer is used to combust gases, which require oxidation due to low heating value.
Gas plant flares: These flares are used to dispose of unusable gas or burn off the gas in an emergency or unsafe situation. The flares remove water, CO2, and natural gas liquids (NGLs) from raw natural gas.
Solution gas flares: These flares are used at facilities with multiple oil- and gas-producing wells. The flares dispose of natural gas, which is recovered and transported to a processing facility via pipelines.
Well test flares: These flares are used to identify the kinds of fluid during the drilling and testing of oil and gas wells.
Gas flaring refers to burning off by-products of associated gas generated during different processes, such as oil and gas production, coal bed methane (CBM) production, landfill gas extraction, and petrochemical processes.
In addition to eliminating unwanted gas, gas flaring is practiced for economical, operational, and safety reasons.
Also known as “associated gas” or “flare gas,” natural gas from oil wells exists separately as “free gas” or dissolved in crude oil. A common practice is to flare natural gas that contains measurable amounts of hydrogen sulfide gas (“H2S” or “sour gas”) to reduce the H2S gas’s high toxicity.
A global survey of natural gas used data that was collected by the National Aeronautics and Space Administration (NASA)/National Oceanic and Atmospheric Administration (NOAA) Visible Infrared Imaging Radiometer Suite (VIIRS). The survey results showed that the upstream production areas accounted for the bulk (90%) of the flared gas volume, with 8% at refineries and 2% at LNG terminals.
According to the World Bank, the annual amount of gas flared (around 144 billion cubic meters (BCM)) could power entire sub-Saharan Africa. The World Bank’s 2022 Global Gas Flaring Tracker Report shows the top 10 flaring countries accounting for 75% of all gas flaring (listed in alphabetical order):
In recent years, the growing crude oil production in the Eagle Ford Shale (EFS) play and the Permian Basin has contributed to a rapid increase in natural gas flaring in Texas. In the U.S., the flaring limits vary with specific flaring and venting regulations for every oil- and gas-producing state.
The report further describes Syria, Yemen, and Venezuela as the countries with the lowest performance with respect to flaring intensity (the volume of gas flared per barrel of oil produced).
The Global Gas Flaring Reduction Partnership (GGFR) defines the main types of gas flaring observed at oil production facilities:
Routine gas flaring occurs during normal oil production operations. In the absence of suitable geology or adequate facilities, it is not possible to reinject the produced gas, utilize it on site, or send it to a market. Such situations require routine flaring that does not include safety flaring.
Examples of routine flaring:
Other than routine flaring and safety flaring, non-routine flaring is intermittent flaring (planned or unplanned) of short duration. Sometimes, non-routine flaring is required for stabilization when process parameters are outside the allowable design or operating limits.
Non-routine flaring is possible during:
Oilfield operators use gas flaring to de-pressurize equipment and manage large pressure variations to prevent potentially destructive and long-lasting fires. Burning excess gas helps control changeable pressures during crude oil extraction—this is where safety flaring helps to ensure safe facility operations.
Examples include flaring of:
The gas flaring system includes components, such as:
While natural gas flaring involves the controlled combustion of natural gas, venting refers to the direct release of natural gas into the atmosphere without burning the gas.
Venting is considered more harmful than gas flaring as unburnt methane emissions carry a global warming potential as high as over 80 times the same mass of CO2 emissions over a 20-year period.
Venting occurs at various stages of the oil and gas development process, including pipeline maintenance, tank maintenance, well completion, and well maintenance. Gas is also vented during liquids unloading on low-pressure gas wells and routine emissions from natural gas-driven pneumatic pumps.
Here are some key differences between gas flaring and venting:
Gas flaring for operational and safety reasons involves the diversion and disposal of:
Natural gas is also disposed of due to maintenance operations, pressure release emergencies, or system upset conditions. Furthermore, disposal of small volumes of waste gas from routine operation equipment at an oil or gas processing facility is common in the oil and natural gas industry.
Flaring for economic reasons stems from the need for early oil production before natural gas capture and the lack of gathering, compression, and sales infrastructure due to financial or operable non-viability. Such flaring is related to associated gas (also known as “casinghead gas”) produced with crude oil.
Another important factor for flaring is a local market that is underdeveloped and/or pays low prices for the gas. For example, remote oil fields, dysfunctional pricing, and limited financial incentives lead to appreciable flaring and reduce the possibility of bringing associated gas to market.
Pipeline shutdown and road restrictions preventing the transportation of liquids also contribute to an increase in flaring.
Bans on gas flaring have been practically ineffective. Potential flaring solutions include developing economically viable gas markets and smaller-scale uses of gas at/near the source, such as building local gas-fired power plants and mobile CNG (Compressed Natural Gas) fueling stations.
Also known as “natural gas venting” or “methane venting,” gas venting is possible due to many factors, including:
In “green” or “flareless” completions, heavy-duty separators (also known as “flowback units”) separate the gas from fluids and solids. The sand is transported to a reserve pit during the process, and the water is discharged to tanks for reuse. Moreover, the gas is pumped down the wellbore or sent to a pipeline to be sold instead of flaring or venting.
Natural gas is a gaseous combination of hydrocarbon compounds and non-hydrocarbon gases. Methane is the primary component of natural gas that contains other hydrocarbons, such as butane, ethane, propane, and pentanes.
Additionally, raw natural gas may contain carbon dioxide, helium, hydrogen sulfide, nitrogen, water vapor, and other compounds.
Gas flaring is considered hazardous to the environment due to the release of global-warming gases, such as methane, which has a significant impact on climate change.
Gas flaring is supposedly necessitated by the absence of gas gathering lines or processing capacity. Moreover, the lack of incentives to sell natural gas promotes gas flaring—a known contributor to greenhouse gas emissions. For example, even a low-producing oil well can generate a large amount of hazardous methane emissions.
Flaring results in the release of various pollutants—depending on the gas’s chemical composition and the flare’s efficiency and temperature.
While one of these pollutants is methane that is more potent than carbon dioxide (CO2), the other climate pollutant released due to incomplete flaring is black carbon (soot or particulate matter).
Black carbon particles can impair lung function and cause health problems like respiratory diseases. Furthermore, black carbon emissions contribute to climate change in various ways, such as by absorbing solar radiation in the atmosphere and accelerating snow and ice melt.
Other air pollutants released from natural gas flares include acetaldehyde, acrolein, benzene, formaldehyde, hexane, and polycyclic aromatic hydrocarbons (PAHs) like naphthalene.
According to a Rice University-led research study, the air quality associated with gas flares from oil and gas fields, primarily in North Dakota and Texas, was attributed to many premature deaths in 2019.
It is estimated that 2 million people live within 2.5 miles of a gas flare in the Niger Delta region of Nigeria—there are serious consequences of staying close to a gas-flaring location.
Worldwide, gas flaring is regarded as a major hazard, which requires mitigation measures in existing or new facilities. Some options to better utilize flared gas and reduce global carbon emissions are:
In addition, commercial solutions for routine flaring facilitate mitigation at new or existing facilities.
On a large scale, flare mitigation opportunities are meant to reduce the environmental impact of gas flaring and put flared gas to better use. Let us explore ways of curbing gas flaring in detail.
Apart from posing a threat to agriculture, public health, and wildlife, gas flaring results in a loss of billions of dollars worldwide. The equivalent of the wasted natural gas is enough to heat millions of homes, and the harmful effect of flaring equals the CO2 emissions of thousands of cars.
One of the main reasons for flaring is that it is cheaper to burn natural gas off than to recover it. Effective, inexpensive, and technologically advanced ways to end flaring are vital to capture and convert natural gas into environmentally safer and marketable materials.
A transparent data collection and disclosure system goes a long way in addressing the challenge of poor or non-existent data collection, as well as auditing venting and flaring volumes. Moreover, investing in pipeline infrastructure reduces the need for routine flaring.
When the potential reward is greater than the challenge, it is also worth investing in flare gas recovery systems that minimize hydrocarbon loss and recover gases for reuse.
Here are some measures, which are crucial to curb current and future flaring volumes (listed in alphabetical order):
In addition, flare tips with more modern designs aid in adequate fuel-air mixing to reduce emissions resulting from poor combustion efficiency.
According to the U.S. Energy Information Administration (EIA), “flaring provides a means for handling the associated natural gas, especially when processing and transportation capacities are unavailable.”
An oil company may flare or vent the gas if it is not economically feasible to market it. However, it is still technically and politically feasible to reduce, and ultimately, eliminate routine gas flaring that results in a waste of precious resources.
What are the viable alternatives to gas flaring?
Here are some promising alternatives with good potential to reduce associated natural gas flaring and venting and convert the gas into marketable/usable products:
The following illustrates the use of gas that would otherwise be burned as a local energy source:
Source: EUA – BCA (EU Action on Black Carbon in the Arctic)
In 2015, the World Bank and the UN Secretary-General launched the “Zero Routine Flaring by 2030 (ZRF) Initiative,” which aims to end a long-standing oil industry practice of gas flaring no later than 2030.
The initiative requires governments and oil companies to end existing (legacy) routine flaring that is reported to result in 400 million tons of CO2-equivalent emissions annually.
Source: IEA, Upstream flaring CO2 emissions by region in the Net Zero Scenario, 1985-2030, IEA, Paris. NZE = Net Zero Emissions by 2050 Scenario.
Until now, we have seen mixed progress towards zero routine flaring.
According to the non-profit advocacy group Environmental Defense Fund, several public companies have approved plans to eliminate routine flaring by 2030.
The initiative has the buy-in from development institutions, energy companies, governments, and oil producers/oil companies. Nevertheless, the ambitious goal of zero routine flaring requires more targeted efforts to treat associated gas as an asset, rather than a waste product.
Despite reporting flared gas volume being a requirement for federally designated top-flaring states, satellite data is hardly used to confirm company-reported flaring totals. Without the wide deployment of specialized infrared imaging technology, it is not possible to measure the invisible emissions from venting.
Although there are established policies on gas flaring, adherence to flaring protocols has largely been ignored in some areas with lax monitoring and enforcement of regulations.
Economically and logistically challenging gas processing is one of the key reasons for gas flaring. Furthermore, processing and utilizing associated gas produced from small and dispersed oil production sites is extremely expensive.
An underdeveloped gas market or insufficient infrastructure prevents the utilization of associated gas—economically capturing and selling gas that would otherwise be flared requires the expansion of gas processing and gas pipeline capacities.
For example, converting flared natural gas into energy can generate power for on-site operations and support electric grids as a source of clean and cheap energy in areas with limited access to electricity.
A decarbonized future is possible only through rigorous regulations and well-rounded gas flaring reduction strategies, encouraging the oil and gas industry to adopt more environmentally conscious practices and limit natural gas flaring.
Gas flaring is a necessary component of oil and gas operations, especially in the upstream sector. Gas is typically flared to prevent explosion risk (by venting large amounts of reactive gases), remove waste products from chemical production processes, and ensure the safe combustion of volatile organic compounds.
Flaring or venting natural gas has a specific purpose at several stages of the oil and gas extraction and production processes—from providing information about the oil or gas composition during well testing to preventing fires or explosions by flaring or venting excess gas at gas-processing plants.
The lack of gas-to-liquid conversion technology for transport, pipeline capacity issues, undermeasuring or ineffective tracking, and weak regulations are further responsible for continued gas flaring and venting.
It may not be possible to eliminate the flaring and venting of natural gas during the routine activities of oil and gas development, including drilling, production, gathering, processing, and transportation operations.
However, there is potential value in limiting both practices and economically recovering natural gas for various applications.
In recent times, gas flaring reductions in countries with high gas flaring levels have been contributing to global efforts to utilize gas rather than waste it without any public benefit.
Although a reduction in global flare volumes is encouraging, we can limit or prevent the polluting, undermeasured, and wasteful practice of routine gas flaring for better utilization of natural gas. Now is the time to move forward for a cleaner, greener, and more sustainable future.