The extraction of highly flammable liquids and gases from the earth is a precise and potentially dangerous operation.
Unplanned over-pressuring of plant equipment can occur during start-ups and shutdowns in production on oil and gas sites, when the volume of extracted gas is uncertain. Flares are used to burn off flammable gas, avoiding a significant build-up of pressure and risk of explosion. It is a critical part of ensuring safety, especially in remote locations.
Unnecessary flaring – known as routine flaring – occurs when gas is flared for reasons other than safety. When crude oil is extracted and produced from onshore or offshore oil wells, raw natural gas also reaches the surface. In areas of the world lacking pipelines and other gas transportation infrastructure, this gas is commonly flared, wasting a valuable energy. In 2015, research found flares accounted for 3.5 per cent of the world’s natural gas consumption.
The alternatives
Researchers are searching for an alternative to gas flaring. Methane, the primary component of natural gas, is a greenhouse gas 34 times more potent than CO2. Without flaring, methane is released into the atmosphere with negative effects on the environment and public health. Ordinarily, methane is a tightly bonded molecule and breaking it apart requires large quantities of water and temperatures close to 1,000°C. This process is costly, with researchers needing to find an economically viable alternative to flaring.
The main solution is Liquefied Natural Gas (LNG). Instead of raising the temperature of natural gas, it lowers it to -160°C, liquefying the product. The condensed liquid form takes up 1/600th of the volume of natural gas, making it easier to transport to markets. When delivered, the stored LNG is regasified and distributed as pipeline natural gas.
LNG reduces the wastage of natural gas resulting from flaring. However, it still has a relatively high cost of production. Combined with storage requiring expensive cryogenic tanks, LNG has been unable to attain widespread use in commercial applications. Additionally, LNG is not a viable method of accounting for fluctuations in natural gas pressures, meaning it will be unable to eliminate safety flaring.
A solution in sight?
Unless new alternatives are found that adapt to uncertain levels of natural gas, flaring will remain the least bad solution in the Oil & Gas Industry. Methods like LNG helps eliminate routine flaring, but high production and storage costs are holding it back. To completely eliminate flaring on oil and gas sites, researchers need to find an economically viable alternative to routine flaring that has the ability to capture and store unexpected levels of natural gas.
