physical properties of petroleum

1. Physical properties of petroleum
Shahab Ud Din
SP18-Ers-005

2. Petroleum
 A latin word “petra” means rock and “oleum” means oil
therefore “rock oil”

3. Physical properties
The physical properties are most
commonly used in petroleum are as
under:
 Density
 Volume
 Viscosity
 Refractive index
 Fluorescence
 Optical activity
 Color
 Odor
 Coefficient of expansion

4. Density
 Its define as weight of a given volume such as pound per
cubic foot.
 density is measured in degrees (°) API (American
Petroleum Institute) gravity.
 Degrees API gravity is calculated by dividing the
specific gravity of the crude oil at 60° F into 141.5.
 It is symbolically represented by the Greek letter rho ρ.

5. Volume
 Oil in the reservoir contains dissolved gas.
 The volume of the solution depends upon the formation
gas-oil ratio and the reservoir pressure.
 Gas may be dissolved in oils by increasing pressure and
increase the volume in solution.

6. Viscosity
 It is define as the internal friction of a moving fluid.
 viscosity is symbolically represented by a Greek letter
eta, η.
 Greater the viscosity of a fluid the less readily it flow.
 Its generally depend on the amount of gas dissolved in it
on the definite temperature .

7. Refractive index
 Absolute refractive index (RI) of a substance is the inverse
ratio of the speed of light.
 The range of refractive indices for petroleum is from1.42 to
1.48.
 The refractive index is dependent on the density of the oils.
 The lower indices are the lighter oils.
 The heavy (lower API Gravity) oils have the higher indicies

8. Fluorescence
 The all oils show more or less fluorescence, also called
bloom.
 The aromatic oils being the most fluorescent.
 Fluorescence is observed under ultraviolet radiation.
 The fluorescent colors of crude oils range from Yellow
through Green to Blue.

9. Optical activity
 Most petroleum has optical activity.
 It is the power to rotate the plane of polarization of polarized
light.
 It is measure with a device called polariscope.
 Its average range is from 0-1.2 degrees
 If the plane is rotated to right the substance is said to be
dextrorotary,
 While if it rotate to left it is called levorotary.

10. Color
 paraffinic oils are light color, yellow to Brown by
transmitted light.
 Asphalt-base oils are commonly brown to black.
 Many of them are known as “Black oils”.
 Color is commonly determined with the Saybolt
Colorimeter.

11. Odor
 Due to the light hydrocarbons some oils is agreeable like
gasoline odor.
 Aromatics impart pleasant odors.
 Oils containing sulphur and certain nitrogen compounds
usually a disagreeable odor.

12. Coefficient of expansion
 It is define as the rate change in the size of an object
with the rate change in the temperature.
 For an increase in temperature of 1˚F varies foe crude
oil from 0.00036-0.00096
 The average coefficient for pennsylvania crude oil is
0.000840.

13. THANK YOU…..!!!!