is the fluid
mixture of oil
in formation fluid
that flows to the surface of an oil well
from a reservoir
. Its consistency
and composition varies.
Fluids may be described by a multitude of characteristics including:
- Water cut - the proportion of the fluid, which is water rather than hydrocarbons.
- API gravity - the oilfield measurement of the weight of the hydrocarbons.
- GOR - Gas to oil ratio describing how many standard cubic feet of gas can be obtained for every stock tank barrel of oil.
- H2S - the concentration of this gas. Fluids with a high concentration of H2S are described as "sour".