Engineers love to speak in terms of ratios – dimensionless, if possible.
Some of the ratios mentioned most often are:
GOR = gas/oil ratio
SOR = steam/oil ratio
WOR = water/oil ratio
Note that a backslash (/) is used – not a hyphen – without any spaces between the words.
The same sort of construction is used for the various fluid interfaces in a reservoir:
GOC = gas/oil contact
OWC = oil/water contact
I like to tell people that my technical writing has a high beef/bologna ratio. That usually makes them smile.