Oil & Gas Terms in Category G

Gas cutting

A process in which gas becomes entrained in a liquid.

Galvanic corrosion

A type of corrosion that occurs when a small electric current flows from one piece of metal equipment to another.

It is particularly prevalent when two dissimilar metals are present in an environment in which electricity can flow (as two dissimilar joints of tubing in an oil or gas well).

Gas cap

A free-gas phase overlying an oil zone and occurring within the same producing formation as the oil.

Gas input well

A well into which gas in injected for the purpose of maintaining or supplementing pressure in an oil reservoir.

More commonly called a gas injection well.

Gas anchor

A tubular, perforated device attached to the bottom of sucker-rod pump that helps to prevent gas lock.

The device works on the principle that gas, being lighter than oil, rises.

As well fluids enter the anchor, the gas breaks out of the fluid and exits from the anchor through perforations near the top.

The remaining fluids enter the pump through a mosquito bill (a tube with the anchor), which has an opening near the bottom.

In this way, all or most of the gas escapes before the fluids enter the pump.

Gas lift

The process of raising or lifting fluid from a well by injecting gas down the well through tubing or through the tubing-casing annulus.

Injected gas aerates the fluid to make it exert less pressure than the formation does; consequently, the higher formation pressure forces the fluid out of the wellbore.

Gas may be injected continuously or intermittently, depending on the producing characteristics of the well and the arrangement of the gas-lift equipment.