- Oil Density
Oil density is required at various pressures and temperatures for reservoir and production engineering calculations. The oil density is defined as the mass per unit volume at a specified pressure and temperature.
The relative density of oil is defined as the ratio of the density of the oil to that of water usually at 60 oF.
The relative density of oil at any other temperature T can be calculated using
In the petroleum industry, it is common to express oil density in terms of oil API gravity, or:
An equation for oil relative density at bubblepoint pressure (Pb) is expressed as
Above bubblepoint pressure, increased pressure will compress the liquid and increase its density. For the case of P > Pb, the oil relative density at P is calculated from
Correlation for calculating average oil compressibility Co at various conditions is presented later.