Light hydrocarbon material, gaseous at atmospheric temperature and pressure, held in the liquid state by pressure to facilitate storage, transport and handling. Commercial liquefied gas consists essentially of either propane or butane, or mixtures thereof.

This describes the process of gathering and recording information about the surface formation. 

A term sometimes used to refer to those industry activities that fall between exploration and production (upstream) and refining and marketing (downstream). The term is most often applied to pipeline transportation of crude oil and natural gas.

A solid and naturally occurring inorganic substance. Minerals are distinguished from one another by careful observation or measurement of physical properties such as density, crystal form and hardness.

MODU stands for Mobile Offshore Drilling Unit. The term is used to categorise self-contained floatable drilling machines.

This measures the fluid pressure and collects small samples in a well.

A term that is generally synonymous with drilling fluid and that encompasses most fluids used in hydrocarbon drilling operations, especially fluids that contain significant amounts of suspended solids, emulsified water or oil. Mud includes all types of water-base, oil-base and synthetic-base drilling fluids.

A naturally occurring mixture of hydrocarbon gases that is highly compressible and expansible. Natural gas is often found in association with crude petroleum. 

The portions of gas from a reservoir that are liquified at the surface in separators, field facilities, or gas processing plants. NGL from gas processing plants is also called liquified petroleum gas (LPG). Natural gas liquids include propane, butane, pentane, hexane and heptane, but not methane and ethane, since these hydrocarbons need refrigeration to be liquefied. 

This is a well in which the formation pressure is sufficient to produce oil at a commercial rate without requiring a pump.

This is a chemical reaction between an acid and a base to form a salt and water. The process involves removing acidic contaminants from muds and formation of emulsifiers in oil mud. 

Natural gas produced from a reservoir that does not contain significant quantities of crude oil.

A mixture of liquid hydrocarbons of different molecular weights.

Drilling mud with which crude oil has been unintentionally mixed. 

An oil field is a geographic area under which an oil reservoir lies. An oil field consists of a reservoir in a shape that will trap hydrocarbons and that is covered by an impermeable or sealing rock.