What is associated gas?
It is the natural gas that comes out of an oil well together with the crude. What the operator does with it decides whether it becomes revenue or smoke.
Crude oil rarely sits alone in a reservoir. Natural gas is dissolved in it, or trapped above it as a gas cap, and when the oil reaches the surface the pressure drops and the gas separates. That gas is called associated gas because nobody drilled for it. It arrived with the oil.
An operator has four things it can do with it. It can pipe the gas to a buyer. It can push it back underground to keep reservoir pressure up and squeeze out more oil. It can burn it on site in turbines or engines to power the field. Or it can flare it, which means burning it at the tip of a stack with no use at all.
Which option wins depends on distance and money. A field close to a pipeline sells the gas. A remote field with no pipeline often flares, because building one costs more than the gas would earn. That gap is why small gas-to-power units, mini-LNG plants and on-site data centres keep getting pitched to oil producers.
- Gas flared worldwide each year
- Roughly 150 billion cubic metres, according to the World Bank's Global Gas Flaring Tracker
- Four uses
- Sell it, reinject it, burn it for power, or flare it
Explainers describe how things generally work. They are not advice for a specific project or country. See our editorial policy.