Page 54 - 5010

LABORATORY EXPERIMENT № 8

DEMULSIFICATION OF OIL AND DETERMINATION OF
THE AMOUNT OF WATER AND MUD IN OIL BY MEANS

OF THE CENTRIFUGATION METHOD

8.1 The objective of the experiment is: to study devices
for mechanical destruction of emulsions and to determine the
amount of water and mud in oil by means of the centrifugation
method.

8.2 Definitions

In formations oil is very often together with water. At strong
shaking these unmixed liquids break into drops and form emulsions.

As a rule intermixing takes place not in the formation, where filtration
is quiet, but in the well and in pipelines on the surface during

the process of oil recovery.

The formation of emulsion is influenced by the well operation

method.
Under stormy flowing (flowing well operation method) there is

strong interfusion of oil, water, gas and sand. It increases at pushing
the mixture through the narrow choke opening. Thus there are
favourable conditions for formation of the emulsion in this case.

On the contrary the amount of emulsion diminishes sharply at

quiet flowing under hydrostatic pressure.

In gas-lift well operation method the mixture of oil, water, gas

and mechanical admixtures quickly goes up through the bore hole
mixing constantly.

When instead of gas, air is used the amount of emulsion

increases and its stability grows up.

There are no rapid motions of mixtures during the downhole

sucker-rod pump well operation method and interfusion is less strong.

Therefore in this case conditions for formation of emulsion are not so
favourable as in flowing and gas-lift methods.

Physical and chemical properties of oil and water influence
the formation and stability of emulsion and they depend considerably

53