Standard cubic foot

A standard cubic foot (abbreviated as scf) is a measure of quantity of gas, equal to a cubic foot of volume at 60 degrees Fahrenheit (15.6 degrees Celsius) and either 14.696 psi (1 atm or 101.325 kPa) or 14.73 psi (30 inHg or 101.6 kPa) of pressure.^[1]

A standard cubic foot is thus not a unit of volume but of quantity, and the conversion to normal cubic metres is not the same as converting cubic feet to cubic metres (multiplying by 0.0283...), since the standard temperature and pressure used are different. Assuming an ideal gas, a standard cubic foot using the convention of 14.73 psi represents 1.19804 moles (0.0026412 pound moles), equivalent to 0.026853 normal cubic meters.

Common oilfield units of gas volumes include ccf (hundred cubic feet), Mcf (thousand cubic feet),^[2] MMcf (million cubic feet), Bcf (billion cubic feet), Tcf (trillion cubic feet), Qcf (quadrillion cubic feet), etc. The M refers to the Roman numeral for thousand. Two M's would be one thousand thousand, or one million. The s for "standard" is sometimes included, but often omitted and implied.

Trillion cubic feet, commonly abbreviated as Tcf, is used in the oil and gas industry. The term trillion here refers to 1×10¹², the short scale definition.

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