Unit of volume; one acre of producing formation one foot thick. One acre foot equals 7,758 barrels, 325,829 gallons or 43,560 cubic feet.

One stock tank barrel, or 42 U.S. gallons liquid volume, used herein in reference to crude oil or other liquid hydrocarbons.

Billion cubic feet of natural gas.

Billion cubic feet of natural gas equivalent.

The abbreviation for barrels of oil per day.

The amount of heat required to raise the temperature of one pound of water one degree Fahrenheit under standard conditions of pressure and temperature.

Pipe cemented in the well to seal off formation fluids or keep the hole from caving in.

The system of pipes, valves, gauges and related equipment that is located on the well at ground level and that controls the flow of gas and other petroleum products produced from the well.

The number of acres which are allocated or assignable to producing wells or wells capable of production.

A well drilled to a known producing formation in a previously discovered field.