Properties
- Last UpdatedAug 14, 2026
- 7 minute read
A property is any quantity, expressible as a single number, which can be measured for a crude oil or product stream. For example:
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Density at 15°C measured in g/cc.
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The 90% point of a D86 distillation measured in °F.
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The Cetane Index using method D4737-90.
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The aromatics content by volume, in %.
Notice that in some cases, information additional to the property name itself is necessary to fully define the property:
|
Additional information |
Example property |
Explanation |
|---|---|---|
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Measurement temperature |
Density at 15°C |
The measurement temperature corresponds to the physical temperature for measurement of the property. It applies to properties such as density, viscosity, refractive index, where the ambient temperature affects the value measured. |
|
Measurement percentage |
D86 at 90% |
This information is only needed for distillation properties, which return a temperature value. For such a property to be complete, it is necessary to specify the percentage, so that a unique temperature value can be defined. |
|
Weight or volume basis |
Aromatics by volume |
This information is needed for measurements of the amounts of pure compounds (such as benzene) or groups of compounds (such as aromatics). |
Additionally, note that some properties can also be categorised in terms of those which can be used to generate cut values (for example to configure columns), and those which can be plotted as profiles (as seen in the graph)
The following list indicates the list of basic properties available in the product, together with their extra information requirements, their unit categories, and their suitability for column configuration and graphing.
Note: your version of the product may be configured to have more than this standard set of properties.
|
Type |
Property Name |
Unit Category (example) |
T? |
%? |
Wgt/Vol? |
Cuts? |
Graph? |
|---|---|---|---|---|---|---|---|
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Yields |
Yield |
Proportion (%) |
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Cumulative Yield |
Proportion (%) |
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True Boiling Point |
Temperature (°C) |
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Densities |
Density |
Density (g/cc) |
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API |
Dimensionless |
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Specific Gravity |
Dimensionless |
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Viscosities |
Viscosity |
Viscosity (cSt) |
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Viscosity Index |
Dimensionless |
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Cold properties |
Pour Point |
Temperature (°C) |
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Cloud Point |
Temperature (°C) |
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Freeze Point |
Temperature (°C) |
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Sulphurs |
Total Sulphur |
Proportion (%) |
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Mercaptan Sulphur |
Proportion (%) |
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Hydrogen Sulphide |
Proportion (%) |
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Nitrogens |
Total Nitrogen |
Proportion (%) |
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Basic Nitrogen |
Proportion (%) |
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Other elements |
Carbon |
Proportion (%) |
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Hydrogen |
Proportion (%) |
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Nickel |
Proportion (ppm) |
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Vanadium |
Proportion (ppm) |
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Groups |
Aromatics |
Proportion (%) |
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Paraffins |
Proportion (%) |
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Naphthenes |
Proportion (%) |
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Naphthalenes |
Proportion (%) |
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Hydrocarbons |
Methane |
Proportion (%) |
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Ethane |
Proportion (%) |
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Propane |
Proportion (%) |
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N-Butane |
Proportion (%) |
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Isobutane |
Proportion (%) |
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N-Pentane |
Proportion (%) |
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Isopentane |
Proportion (%) |
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Residue |
Carbon Residue |
Proportion (%) |
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Asphaltenes |
Proportion (%) |
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Fuels |
Research Octane No. |
Dimensionless |
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Cetane Index |
Dimensionless |
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Flash Point |
Temperature (°C) |
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Smoke Point |
Length (mm) |
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Aniline Point |
Temperature (°C) |
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Other |
Refractive Index |
Dimensionless |
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Acid Number |
Acidity (mgKOH/g) |
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Watson K |
Dimensionless |
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Wax |
Proportion (%) |
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Basic properties available in Assay (T=Temperature, %=Percentage, Wgt/Vol=Weight or Volume)