A new family of demulsifiers is introduced that very effectively destabilizes water-in-oil emulsions such as those encountered in produced crude oil, particularly oil produced by steam injection or waterflooding. The demulsifiers are unique in their high solubility in water and can, therefore, be effectively used in acid formulations in which demulsifiers are used to prevent sludge formation downhole.

Experimental results are presented on emulsion stability for crude oil-water systems. Such emulsion stability tests allow us to compare the new demulsifier with existing demulsifier formulations such as nonylphenol formaldehyde resins that are extensively used today. Drop coalescence tests are presented to confirm the results of the emulsion stability tests. Dynamic surface tension measurements are used to measure the surface dilational properties of oil water interfaces containing the new demulsifier. It is clearly shown that low characteristic relaxation times and high dilational elastic moduli correlate well with emulsion stability and can be used as a criteria for selecting demulsifier formulations. The variation of interfacial tension with surfactant concentration is presented to measure interfacial areas of the demulsifier molecules adsorbed at the oil/water interface using the Gibbs equation. This also allows us to compute the CMC of the new formulations.

A wide range of surfactant properties can be obtained by changing the degree of functionalization of the base molecule. When used in combination with other demulsifiers it is extremely effective at breaking water-in-oil emulsions. It's water solubility makes it particularly attractive for use in aqueous formulations that are used for well treatment, such as acidizing formulations.