Variations in crude oil density are shown as function of temperatur, together with volume correction factors.
Correlations for crude oil density and temperature are found by use of tools based on ASTM D 1250-04 and IP 200/04 (API Manual of Petroleum Measurement Standards, Chapter 11- physical properties Data, Section 1:Temperature and pressure volume correction factors for generalised crude oils, refined products and lubricating oils). Each colored line represents a crude oil with a given density at a given temperature. If the temperature changes, the density of the crude oil changes along the colored line.
Examples of the use of the figures are given below the figures.
If you have the crude density given in °API, use the API-to-gravity converter.
See also similar correlations for lubricating oil, fuel oils and jet fuel.
Volume correction factors can be used to calculate the volume of a crude at base temperature (15°C/59°F) if you know the density and volume at another temperature. Or, if you know the base volume and density, you can use the volume correction factor to calculate the volume at another temperature. To be sure you have used the correct figure for correction factors, the easy rule is that the volume increases with increasing temperature.
You have 100 liters of a light crude oil with a density of 761 kg/m3 at 50°C. What is the volume at 15°C?
In the Density vs temperature figure(°C), you se that the light grey line represent this crude oil.
Then, use the light grey line in the Crude oil volume correction figure (Density@Observed T/Density@15°C). At 50°C the correction factor is 0.965.
The volume of your crude oil at 15°C is 100liters*0.965 = 97 liters. (Easy check: Lowest volume at the lowest temperature)
You have 1000 m3 of a heavy crude oil with a density of 970 kg/m3 at 15°C. How will the volume change if you heat it to 250°C?
In the Density vs temperature figure (°C), you see that the dark grey line represent this crude oil.
Then use the dark grey line in the Crude oil volume correction figure (Density@15°C/Density@observed T). At 250°C the correction factor is 1.188.
The volume of your crude oil at 250°C is 1000m3*1.188 = 1188 m3. (Easy check: Lowest volume at the lowest temperature)