A more thorough explanation:

CASINGHEAD GAS

Casinghead gas is a type of natural gas that is found in a liquid form along with crude oil. It is produced at the top of an oil well, which is called the casinghead. When the oil is extracted, the casinghead gas separates from the oil either during or shortly after production.

When oil is extracted from a well, casinghead gas is often produced along with it. This gas can be used as a fuel source or processed to remove impurities and used for other purposes.

For example, some oil companies use casinghead gas to power their drilling equipment or to generate electricity for their operations. Others may sell the gas to third-party companies for use in industrial processes or as a fuel for vehicles.

Casinghead gas is a natural byproduct of oil production that can be used as a valuable resource. Its separation from the oil during production makes it easier to extract and process, and its availability at the wellhead can make it a cost-effective fuel source for oil companies and other industries.