Experimental Investigation of Emulsion Stability in GOSPs, Part II: Emulsion Behavior

This paper presents an experimental study performed jointly by IFP and Saudi Aramco to characterize the stability of emulsion samples collected from different Saudi Aramco Gas Oil Separation Plants (GOSPs). The first part of the study 1 (SPE 106128) focused on the analyses of separated phases. Many techniques (differential scanning calorimeter, Karl Fisher coulometer, rheology, optical microscopy, cryoscanning electron microscope) were applied to analyze and characterize the separated phases: crude oil, emulsion and free water. In the second part of this study, the stability of residual emulsions was investigated against several chemical demulsifiers by using classical bottle tests and an automated, vertical-scan, macroscopic analyzer (Turbiscan). This instrument is used to obtain kinetics of separation of concentrated and opaque dispersed systems such as emulsions, suspensions and foams. Interfacial tension measurements were also made to obtain information about the interfacial behavior of samples including viscoelasticity properties of the film. The results of transient emulsion separation experiments provide some useful insights into their behavior, stability and tightness. The study highlights the main physicochemical parameters responsible for the varying tightness of these emulsions, and provides recommendations to optimize their treatment costs and resolve emulsion issues in the GOSPs.