The gas/oil ratio (GOR) is the ratio of the volume of gas that comes out of solution, to the volume of oil at standard conditions.
The GOR is a dimensionless ratio (volume per volume) in metric units, but in field units, it is usually measured in cubic feet of gas per barrel of oil or condensate.
In the States of Texas and Pennsylvania, the statutory definition of a gas well is one where the GOR is greater than 100,000 ft3/bbl or 100 Mcf/bbl.