Associated Free Gas
Definition - What does Associated Free Gas mean?
Associated Free Gas is the gas that is present in a reservoir either dissolved in crude oil or freely available in the reservoir on top of the crude oil. It is usually natural gas or methane. Natural gas which is produced along with crude oil is known as associated gas while natural gas which is produced alone is known as dry gas. Associated free gas may be produced freely or as associated petroleum gas (APG).
Petropedia explains Associated Free Gas
Natural Gas is a fossil fuel which is used as a source of energy. It is the safest, cleanest and most environment friendly source of energy. Reservoirs that contain hydrocarbons usually contain liquids such as crude oil, natural gas and water. In a reservoir, natural gas being the lightest of all, is present freely on top of crude oil or dissolved in the crude oil and thus, referred to as associated free gas. A hydrocarbon reservoir is a primary source of hydrocarbons production. In case of natural gas, the reservoir can be either classified as associated gas reserve or non-associated gas reserve.
Associated gas reserve is responsible for producing associated gas. This is the associated free natural gas which is produced as an alternate substitute along with crude oil production. In the 19th century when natural gas was not that predominant, associated natural gas was considered as a byproduct of crude oil. It was flared and vented into the atmosphere or injected back into the reservoir. However, with increased demand of natural gas these days, E&P organizations make sure that they separate the associated gas from crude so that it can be processed and sold to natural gas marketers.
In a non-associated gas reservoir, only natural gas is produced which is called dry gas.