Gas Flaring: What Is It and Why Is It Done?
Flare gas is a natural by-product of industries such as oil and gas recovery, landfill gas production and wastewater treatment. For safety and regulatory reasons, this gas needs to be monitored, managed and removed, which is often done by gas flaring. This process began over 160 years ago with the very start of oil production and is a way of eliminating unwanted gas that has been brought to the surface via combustion.
What is gas flaring?
Gas flaring is the burning of natural gases often associated with oil extraction. It is a relatively safe way to dispose of excess gas, but it is often considered to be wasteful and polluting. Gas flaring can be a major environmental concern as the process generates a large amount of greenhouse gases such as carbon dioxide and methane which can contribute to global warming. Worldwide, it results in over 350 million tons of CO2 emissions each year and can be a waste of a very valuable resource.
How does gas flaring work?
Gas flaring in the oil and gas industry is done using a flare made up of a boom or stack which collects the unwanted gases for flaring. The tip of the flare is comprised of an air-assist mechanism which combines free air with generated gases to improve the combustion efficiency. Depending on the gases in question, they may require oxidation and are combusted using a thermal oxidizer.
Why does gas flaring take place?
Gas flaring takes place due to a range of reasons, often when it is not economically viable or there are certain regulations in place that prevents the gases from being stored and utilized.
Routine gas flaring
On oil extraction sites, gas flaring may take place on a routine basis. This can be the result of there not being sufficient facilities available to utilize the natural gases or dispatch it to a market. Amenable geology may not be available to reinject the produced gas either.
Gas flaring may be carried out due to safety reasons. Extracting and processing oils and gases often involves dealing with very high and changeable pressures, particularly in industries such as crude oil extraction. When a sudden increase in pressure occurs it can cause an explosion, leading to destructive and long-lasting fires which are difficult to contain and control. Carrying out gas flaring will allow the operators to depressurize their equipment and manage any large pressure changes by burning the excess gases.
Certain oil extraction sites may be too remote or inaccessible which makes it very difficult to collect and transport gases. Additionally, these sites may not produce consistent quantities of gas, or the sites may be smaller or spread out over large areas. In these instances, it is not logistically or economically viable to transport these gases to locations where they can be processed and used.
In certain countries, it may be difficult or even forbidden to sell natural gases that have been obtained as a result of oil extraction. The local regulations may specify how gases can be handled commercially or may strict the rights of companies to sell the gases. When this occurs, gas flaring is one of the only safe and suitable solutions.
Alternatives to gas flaring
In recent years gas flaring has fallen out of favor as it is seen as a waste of valuable natural resources which can be otherwise used for productive purposes. Some of the common alternatives to gas flaring today include:
Recycling natural gases for heating or electricity
One way to mitigate the environmental impact of the oil extraction industry is to collect these natural gases and use them to generate power for heating or electricity or even conserve it for future use. According to World Bank, 144 billion cubic meters of gas is flared each year which if used, could power the whole of sub-Saharan Africa.
Re-injection of gases
When amenable geology is available, the natural gases may be able to be reinjected back into the ground or aged wells. This will restore the dwindling natural formation of pressure and maintain production outputs, resulting in a self-sustaining cycle which is very economical and with minimal waste.
Feedstock for petrochemical plants
Natural gases are used in petrochemical production processes and flare can be channeled into producing ammonia, syngas, hydrogen fuel for cars or even used in manufacturing rubber, glass, steel and paint.
Liquefying and storing
Liquefying and storing gases is a safer and more economical solution to flaring. After purification processes take place, the gases can be stored and used on both an industrial and domestic scale.
Methane that has been collected from landfills or oil wells can be compressed and stored at high pressure in cylinders. This gas can then be used to power vehicles that run on natural gas engines.
Now you know what gas flaring is, why it is carried out and the suitable alternatives available. Next up, find out more about our gas flare monitoring solutions.