I introduction of natural gas

Natural gas refers to the combustible gas buried underground, and its main component is methane (CH4). There are four main forms of natural gas:

1. Gas field gas

Combustible gas produced by gas wells is called pure natural gas or gas field gas. Its main component is methane (CH4), accounting for more than 90%. In addition, it also contains a small amount of ethane (C2H6), propane (C3H8), hydrogen sulfide (H2S), carbon monoxide (CO), carbon dioxide (CO2) and so on. Its calorific value is about 38MJ/Nm? .

2. Condensed gas field gas

The condensate gas field means that natural gas contains more C5 and above petroleum light hydrocarbon fractions, which can be condensed out in the production process, but it does not produce heavier crude oil at the same time. Its main component contains not only a large amount of methane (CH4), but also 2%-5% C5 and above hydrocarbons, with a calorific value of about 46MJ/Nm? .

3. There is a connection between oil and natural gas

Petroleum associated gas refers to the natural gas produced together with liquid oil in the process of exploitation, which is a by-product of petroleum production. Its main component is also methane, accounting for about 70%-80%, and it also contains some other alkanes, as well as CO2, H2, N2 and so on. The calorific value is about 42MJ/Nm? .

4. Coal mine gas

Coal mine gas refers to coal mine gas extracted from underground coal seams and is a by-product of coal mining. It is actually a mixture of coalbed methane and air. Its main components are methane (CH4) and nitrogen (N2), in addition to O2 and CO, etc. It is worth noting that mine gas can be used as fuel gas only when the CH4 content is above 40%. When the volume composition of CH4 is between 40% and 50%, the calorific value of mine gas is about 17MJ/Nm? .