22 Nov

A demulsifier is a type of chemical additive used in various industries, particularly in oil and gas production, to separate emulsions. Emulsions are stable mixtures of two immiscible liquids, such as oil and water, where small droplets of one liquid are dispersed within the other. In the case of oil and water emulsions, demulsifiers are specifically designed to break down these mixtures and facilitate the separation of the oil and water phases.

Demulsifiers work by destabilizing the emulsion and causing the droplets to coalesce, allowing them to separate more easily. They typically act by reducing the surface tension between the oil and water phases or by disrupting the protective films around the droplets, promoting their coalescence. Once the emulsion is destabilized, the oil and water phases can be separated through physical methods such as gravity settling, centrifugation, or using separation equipment.

Demulsifiers are important in the oil and gas industry as they help improve the efficiency of oil production processes, allowing for easier separation of oil and water. This separation is crucial for the proper handling, transportation, and processing of crude oil. Demulsifiers can also be used in other industries where emulsions need to be broken, such as in wastewater treatment, chemical manufacturing, and food processing.

Why are demulsifiers important?

They are frequently employed in extracting crude oil, commonly produced in conjunction with sizable amounts of saline water. It is essential that the water (and salt) is removed to avoid corrosion issues during the refining process. A demulsifier is also known as an emulsion breaker or emulsion inhibitor.

The crude produced from early oil fields contained little to no water when they were first developed, allowing operators to ship the crude oil directly to the refinery with minimal specialised emulsion-breaking machinery and chemical technology. But today, water is a by-product of oil production that cannot be avoided. Oil and water emulsions are present in around 90% of produced crude oil. To dissolve this emulsion, it is necessary to remove or neutralise the natural emulsifying ingredient, causing droplets of water to clump together into bigger ones.

Demulsifiers commonly utilise the following chemistry:

  • Acid or base-catalysed phenol-formaldehyde resins
  • Polyamines
  • Di-epoxides
  • Polyols

To achieve the necessary level of water/oil solubility, they are usually modified. Ethylene oxide enhances water solubility when added, and propylene oxide decreases it. Demulsifier formulations often combine two to four distinct chemistries in one or more carrier solvents, such as HAN, IPA, methanol or xylene.

Demulsifier Measurement

Measured by Litre Meter’s VFF product range in numerous oil fields worldwide, including Jack & St. Malo, Lucius, Gulfstar, P52, Stampede, Skarv, Nawara, Montrose, Sarsang, Culzean, Clair, Triton, Chim Sao, Baobab, West Nile Delta, Jasmine, Ichthys and Armada. Viscosities can range from 2.5 to 111cP. Injection rates vary with production, and we have seen rates from 0.08 l/hr to 70 l/hr. Out of the 30 demulsifier projects we keep track of, we can reveal that 20 are Exd and 10 are Exi installations. Litre Meter usually offers the flameproof FlowPod for Exd areas.

Call us for your next demulsifier application.