Effect of Rheology Properties of Oil/Water Interface on Demulsification of Crude Oil Emulsions

Abstract

Chemical demulsification is widely used in the petroleum industry to remove water from crude oil all over the world. In this work, the relationship between the rheological properties of oil/water interfacial film and demulsification of crude oil emulsions was investigated. The results showed that the elastic modulus was the critical factor for the dehydration ratio, the emulsions showed high dehydration ratio when demulsifiers reduced the elastic modulus of oil–water film to a certain extent (below 5 mN/m). Correlations between dehydration ratio and equilibrium interfacial tension, dynamic interfacial tension, and loss modulus were also investigated. The results showed no correlation between the interfacial tension (IFT), the loss modulus, and the dehydration ratio. However, correlations were observed between dynamic IFT, loss modulus, and demulsification speed when the demulsifier could reduce the elastic modulus of the oil–water film to <5 mN/m. The loss modulus was directly proportional to the surface viscosity and could influence the demulsification speed, but it was not the critical factor. The dynamic interfacial tension was decisive factor to influence the demulsification speed. Dynamic Interfacial tension could be used to characterize the adsorption time (τ1) and the reorganization time (τ2) of demulsifier molecules at the interface, with the decrease of the τ (τ = τ1 + τ2), the demulsification speed increased. The rupture rate constant (k) of interfacial film increased with the decrease of τ, which accelerated the thinning and rupture of the film, thus increasing the demulsification speed.

Synthesis and Application of New Amphiphilic Asphaltene Ionic Liquid Polymers to Demulsify Arabic Heavy Petroleum Crude Oil Emulsions

“…M5 showed a greater reduction in the IFT values using the W:O (50:50). These data showed the ability of the demulsifier blends to penetrate into the rigid asphaltene layer on the dispersed water or oil droplets to demulsify the dispersed phase [46]. The great reduction of IFT values in short times from 5 to 20 min showed the formation of mixed interfacial films with asphaltene at the oil-water or water-oil interfaces.…”

Novel Star Polymeric Nonionic Surfactants as Crude Oil Emulsion Breakers

“…where C o is the magnitude of water within the origin sample without demulsifier and C d is the volume of water detached when integrating the demulsifier (Wang et al, ; Tao et al, , pp. 4851–4860).…”

A critical review of development and demulsification mechanisms of crude oil emulsion in the petroleum industry

“…To date, many researchers (Yang et al 2018;Adewunmi and Kamal 2019;Biniaz et al 2016) had demonstrated the demulsification mechanisms of water-in-crude-oil emulsion as well as of crude-oil-in-water emulsions (Martínez-Palou et al 2013;Tao et al 2015). The studies of both types of emulsions are in mutual understanding of the emulsion stability formation and future needs to break the emulsion.…”