A fluid mixture of mid-density and/or high-density alkanes that stays mostly liquid or semi-solid at Normal Surface Conditions (NTP).
The usual composition ranges from C1 to C32 and API gravity is between 4° and 42° (Specific Gravity is 0.816 ÷ 1.0).).
It may also include minor organic and inorganic chemical substances (usually < 7% in weight).
The total range of oil densities is often classified in the following sub-ranges:
Fig. 1 – A range of different gravity oil compositions from heavy at left to the light at right ( Dubost et al (2007) in SPE-108494 ). One can see how the colour is changing from dark brown for Black Oil (at left) to the light yellow for Volatile Oil(at right). |
In case Oil does not contain dissolved gas it is called Dead Oil otherwise it is called Live Oil.
See also
Natural Science / Physics / Chemistry / Chemical Substance
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petroleum Geology / Petroleum fluids