The gaseous components of crude oil are mainly methane, ethane, propane and butane.
When these gaseous and volatile components are lost or absent from crude oil, then that oil is in a dead state.
This crude oil is very thick, viscous and looks like residue.
Dead oil is treated at a lower market value as compare to other petroleum products.
Examples of dead oil are Tar, heavy oil and bitumen.
After being produced to the surface, if all the gases and volatile components get stripped out of the crude oil eventually, then the remaining oil is termed dead oil.
Under reservoir conditions, oil existing in a dead state will be difficult to produce from the reservoir.
Although oil can be made dead at the surface by mechanically stripping it of all gases and volatile components; some oils are found in a dead oil state right in the reservoir; for example bitumen or tar sands.
These crude oil types flow with difficulty due to their very high viscosity.
One way to lighten the oil is by re-injecting gases and volatile compounds into the reservoir.
This will make the oil less viscous and more pumpable.
Another popular method is by steam injection which makes use of heat to reduce the oil viscosity leading to an increase in oil production.
1519
Dead oil
An oil sample is pronounced dead when it has lost all its dissolved gases and volatile components