Formation of fluid heavy oil-in-water emulsions for pipeline transportation

The diverse factors affecting the viscosity of a surfactant stabilized visc ous crude oil-in-water emulsion for pipeline transportation were studied. T he study discloses that the stability of the oil-in-water emulsion stabiliz ed by a nonionic surfactant Nonyl Phenol Ethoxylate increases as the surfac tant concentration increases with a subsequent decrease in the crude-oil-wa ter interfacial tension (IFT). Increasing the oil content and the speed of mixing of the emulsion resulted in an increased emulsion stability. Fresh water and synthetic formation water were used to study the effect of aqueous phase salinity on the stability and viscosity of the emulsion. Surf actant dissolved in synthetic formation water was utilized to find out the possibility of injecting the surfactant into a well bore to effect emulsifi cation in the pump or tubing for the production of heavy crude oils as oil- in-water emulsion. The effective viscosity of a viscous Egyptian crude oil (Geisum crude oil) decreased when it was emulsified with water in the presence of a nonionic s urfactant in the form of an oil-in-water emulsion. It was possible to form stable emulsions with synthetic formation water characterized by a low dyna mic shear viscosity. This will enhance the production of viscous crude oils by injecting surfactant dissolved in formation water to affect downhole em ulsification. Further, the produced crude oil-in-water emulsion is characte rized by its low effective viscosity which will facilitate its pipeline tra nsportation to the refiner. (C) 1999 Elsevier Science Ltd. All rights reser ved.