As water generally exists with oil in the reservoir, the oil is in most cases produced in the form of an oil/water emulsion. During extraction, the shearing effect of flow in formations pores, pumps and completion restrictions leads to build up more or less stable emulsions.

Emulsion stability is increased by native or added surfactants. Finely, divided solids like iron sulfide, asphaltenes, paraffins, clays and silts could also participate to emulsion stabilisation. Those different products concentrate at oil and water interfaces and enable even low shear rate to fragment dispersed water droplets and form a more or less rigid film at the interface, preventing dispersed phase coalescence. Electric charges of those elements create repulsive strength between droplets, leading to more stable emulsion.

In oil production today, water is an inevitable byproduct. In fact, nearly 90% of crude contains oil and water emulsions. The gradual encroachment of water into oil-bearing formations and the advent of secondary and tertiary recovery methods has led to the development of new technologies to break crude oil and water emulsions.

Dew emulsion breakers are designed to resolve emulsions caused by the process of extraction and production of crude oil. The result is substantially anhydrous crude petroleum at minimum cost to the operator. Operators attain exceptionally rapid oil-water separations with Dew’s demulsifiers, which treat virtually all types of emulsions.

Dew continues to develop new emulsion breakers for the oil and gas industry today. New areas of research include production enhancement through downhole viscosity reduction and improved separation of heavy crude emulsions such as those found in the recovery processes.

Our emulsion breakers offer the benefits below, including:

• Rapid, sharp separation
• No heavy metals or organic halides added
• Versatility in treating all types of emulsions
• Convenient to handle, easily dispersed

In an emulsion, the speed of droplets settling depends on their radius, mass difference between the phases and viscosity.

Demulsifiers (emulsions breaker) act to increase water droplets radius and decrease viscosity. This is achieved by reducing the repulsive forces and interfacial tension, dewatering, neutralising zeta potential and reducing viscosity of interfacial film. Due to diversity of oil and productions parameters demulsifiers must be designed specifically for each oilfield. Aging of emulsions leads to changes in their characteristics.

Formulated emulsion breaker comprises several different active substances carefully balanced:

• The type and amount of non ionic surfactants for interfacial film destruction
• The type and amount of ionic surfactants for electric forces neutralisation
• Final tuning of demulsifier, taking in account production specificities and other chemicals in the stream

Localization of injection point is also a key factor.It must be located as upstream as possible, to allow longer contact time and shear of emulsion in the facilities. The resulting decrease of fluids viscosity reduces production costs and enable higher flow rate.

Dew has exclusive chemicals for asphaltenes and paraffins treatments. Those specifics products are very efficient to control hard to break emulsions generated by paraffinic or asphaltenic crudes.