Characterization and Stability Analysis of Crude Oil-in-Water Emulsions

Abstract

Abstract

Produced water in the form of oil-in-water emulsion is the largest waste stream generated during the oil and gas production. Characterizations of oil-in-water emulsion in terms of stability study with respect to oil droplet size distribution, oil content, total dissolved solids, salinity with respect to time and rheological property have been investigated in the present work. Particle size distributions of freshly prepared oil-in-water emulsion of different crude oil concentration and equilibrated emulsion after regular time intervals have been studied for stability. The results show that with increasing settling time the average droplet size decreases slightly for low oil concentration emulsion but decreases more rapidly for high oil concentration emulsions. Consequently, oil content decreases slightly for low oil concentration and more for high oil concentration emulsion with time. The results indicate that the effects of droplet size and oil concentration in emulsions on the stability and viscosity of oil-in-water emulsions are important. The emulsions show shear thinning behavior when the oil content higher than 400 ppm and average oil droplet size less than 1000 nm.

Keywords: Produced water, Emulsion, Particles size, Total dissolved solids, Rheology