Oil Field unit for natural gas volume: 1 boe = 6,000 bbl = 170 m3
The above is the USGS convention.
The alternative convention is provided by U.S. Internal Revenue Service as : 1 boe = 5.8 · 106 btu in energy terms which is equivalent to 1 boe = 5,800 bbl in volumetric terms.
See also
Natural Science / Engineering / Measurement / Unit
[ Tonne (oil) ]
6,000 cubic feet (170 cubic metres