Rheological properties of crude oil emulsion

Abstract

Emulsion either water-in-oil or oil-in-water emulsion can be important in almost all stages of upstream activities in petroleum industry such as drilling, completion, production, transportation and separation of emulsified crude oil. For instances heavy crude oil have become increasingly important sources of hydrocarbons in many part of the world which transportation of these heavy crude to the refinery can be a problem, and the formation of crude oil emulsion due to high paraffinic compound existed in the crude causes problem in dewatering stage of the crude emulsion. Production of stable emulsion at high temperature and pressure has lead to the design of many new fracturing fluid systems and new drilling fluid systems. The inversion of the type emulsion at higher concentrations of dispersed phase has been utilized as a helpful process for transporting crude oil for long distances through pipeline. Therefore, a knowledge of the rheological behaviour of these emulsions, under both laboratory and field conditions, is important to choose the right approach in designing the required facilities. In order to get better understanding the effect of various influencing parameters on rheological properties of crude oil emulsion, the synthetic crude oil emulsion prepared by using crude oil sample and Triton X-100 was studied at various temperature and water concentration. Brookfield Digital Rheometer was used to measure the rheology of the emulsion. The results showed that at low water concentration the emulsion behaves as a Newtonian fluid, however, at high water concentration it behaves as a non-Newtonian fluid. It was also observed that the viscosity decreases with temperature and the highest velocity was observed at the point close to phase invasion.