Glossary:Flaring

Controlled burning of hydrocarbons mainly for safety reasons.

(Note 1 - Flaring also reduces hydrocarbons to CO2 and water, thus lowering the global warming impact of the released gases.

Note 2 - A definition for “routine flaring” will be included later)

Flares, including open-tip and enclosed combustion systems, are a safety device at many oil and gas operations that are used to control emissions of gas that would otherwise be emitted to atmosphere. Flaring is the controlled burning of natural gas including associated gas in the course of oil and gas operations. An intentional, controlled burning of natural gas that takes place during production and processing. Gas is ignited at the top of a flare stack, creating a characteristic flame. A gas flare, also known as a flare stack, is a gas combustion device used in industrial plants (i.e. petroleum refineries), chemical plants, natural gas processing plants, landfills and at oil and gas production sites, both offshore and onshore. Combustible gases are flared most often due to emergency relief, overpressure, process upsets, startups, shutdowns, and other operational safety reasons. Unplanned flaring happens when an unexpected gas volume has to be addressed as a safety issue. Planned flaring happens when the pipeline infrastructure to economically transport the natural gas to market doesn’t exist. Natural gas that is uneconomical for sale is also flared. Often natural gas is flared as a result of the unavailability of a method for transporting such gas to markets. The gases are piped to a remote, usually elevated, location and burned in an open flame in the open air using a specially designed burner tip, auxiliary fuel, and steam or air. https://www.eia.gov/tools/glossary/index.php?id=F

In many cases, the volume of gas sent to flares is metered or can be calculated from known production parameters, like gas-to-oil ratio. The combustion efficiency of a well-designed and operated flare is generally assumed to be greater than 98%, meaning less than 2% of the gas passes through the flare stack unburnt. This is referred to as slip. For an unlit flare, parametric information about the pilot light status, such as a thermocouple or flame scanner, or other operational data like a visual report from the last site inspection can be used to determine the duration of an unlit flare event. At the individual flare level, local parameters, such as gas content and quality, flare-design, flow rates, exit velocities and steam use contribute to the overall combustion efficiency. There are currently no straightforward methods to continuously measure or monitor the actual combustion efficiency or destruction and removal efficiency of a flare.

The practice of flaring has resulted in the burning of large quantities of gas with the release of large amounts of carbon dioxide together with sulfur dioxide and nitrous oxide, which have contributed substantially to atmospheric pollution. In order to better understand the scale of the problem, it is sufficient to observe nocturnal images of Earth from space: the gas flaring activity in regions corresponding to the major petroleum producing areas are a proof that cannot go unnoticed.

Routine flaring is the flaring of gas during normal oil production operations in the absence of sufficient facilities or amenable geology to reinject the produced gas, utilize it onsite or dispatch it to a market.

Routine venting - Routine venting refers to the intentional release of natural gas into the atmosphere from oil and natural gas equipment. This equipment includes (but is not limited to) pneumatic devices, glycol dehydrators, compressor seals, casing vents, and atmospheric tanks.