Question

Crude oil is rarely produced alone as it is generally commingled with water that creates a number of problems during oil production. Emulsion is a dispersion of droplets of one immisicible liquid into another. Evaluate the factors influencing the stability of emulsions

Answer 1

In crude oil there are impulsion between water and oil which are often very stable. There are some factors who play important roles in the formation and stability of water and oil emulsion like asphaltenes and resin. Asphaltenes are defined as the fraction of the crude oil precipitating in pentane, hexane, or heptane, but soluble in benzene.resins are molecules defined as a being soluble in a light alkanes( pentane , hexane or heptane) but insoluble in a liquid propane they consist mainly of a napthenic aromatic hydrocarbons; Generally aromatic ring system with alicylic chains. Reoins are effective as dispersants of asphaltens in crude oil.

Emulsions: It is defined as the celloiddal system in which fine droplets of one liquid are dispersed in another liquid where two liquids otherwise being mutually immiscible.

Oil and water produce emulsion by stiring; However, The emulsion start to break down immediatly after stirring is stoped.

The Emulsion are classified as , oil and water emulsion or oil and droplet in water, And water oil imulsion or water droplet in oil.

Emulsion formation:

There are some necessary criteria for formation of crude oil emulsion.

1. Two immiscible liquids must be brought in contact.
2. Surface active component must present as the emulifying agent.

Sufficient mixing or agitating effect must be in order.

Stabilization of the emulsion:

There are many factor that usually favour emulsion such as low interfacial tension , high viscosity of the bulk phase and relatively small volume of dispersed phase.

• Surface tension depend on the cohesive force. If the cohesive force of crude oil will be greater than the cohesive force of water molecule then there will be of emulsion water droplet in crude oil.
• Viscosity also depends on the emulsion because it is internal resistance offered by the layer of the fluid it should be high for stability of emulsion.

The volume should be low of dispersed phase for stable emulsion.​​​​​​​​​​​​​​