Improvement of coalescence probability model based on dilational interfacial rheology: effect of formulation, composition and drop size dependence

Abstract

Crude oil remains the most important source of energy in the world. Electrical Submersible Pumps (ESP) are commonly used as artificial lifting system of crude oil, and the shear produced by the ESP causes the emulsion formation, and the phase inversion phenomenon, which is considered one of the most challenging ESP operation in oil production. Emulsions are kinetically stable systems due to the self-formed interfacial film consisted of surface-active molecules (surfactants), and its destabilization occurs through countless steps of droplets coalescence. Over the last years, studies have been conducted to understand the coalescence process, however, many questions regarding this phenomenon remain unanswered. Hence, the improvement of knowledge is mandatory, once the coalescence process is the key to understand emulsion stability, making possible the prediction of emulsions lifetime through models. Studying coalescence based on water/oil interface properties is highly relevant for several technological processes, including the oil industry. The knowledge about the coalescence process may help to improve the efficiency of water/oil emulsions separation, the prediction of phase inversion, and the emulsion breaker efficiency in oilfield. Thus, this project aims to improve coalescence probability model through dilational interfacial rheology properties to obtain a practical and accurate prediction of emulsion stability, besides that the improvement of the coalescence process knowledge. For that, we will evaluate the coalescence probability in different emulsion model systems by monitoring bottle test experiments, and correlate these observations with dilational interfacial rheology properties. Emulsion formulations will be planned by using different surface-active molecules (ionic, nonionic, low weight polymers and asphaltenes), organic phases and aqueous phases. As it is known, the emulsion lifetime depends also on the average droplet size, then the effect of droplet size dependence on the coalescence process will be evaluated by different emulsification methods, as well as the water/oil ratios. In this way, this project will focus on understanding the coalescence process in different formulations to enhance the control of the emulsion stability in several technological applications, where the academic research is applied into technological processes. (AU)