Reservoir Fluid
Reservoir Fluid : A natural underground accumulation consisting primarily of hydrocarbon compounds. The reservoir fluid may be either a liquid or a gas and may contain certain non-hydrocarbon compounds. The non-hydrocompounds which are of greatest importance in sampling are nitrogen, carbon dioxide, hydrogen sulfide, helium, and water. Free water (brine) which flows into the well with the reservoir fluid is not considered here to be a part of the reservoir fluid. (RP 44)