Rheological properties of water-oil emulsions of Archinskoe oil deposit

Abstract

Relevance. The development of new methods for regulating the rheological properties of water-oil emulsion using thermal and chemical methods will allow reducing the viscosity of oil well products and energy consumption for pumping hydrocarbon mixtures. Aim. To determine the activation energy of viscous flow and particle sizes of the internal phase of the initial emulsion of the Archinskoe deposit and the emulsion with an introduced demulsifier. Methods. All experiments required to investigate the rheological properties of colloidal disperse systems were performed using HAAKE Viscotester iQ rotational viscometer. Results. Comparative experimental studies were carried out on the effect of the introduced demulsifier on the effective viscosity of the water-oil emulsion of the Archinskoe deposit. Laboratory-scale experiments were performed using the rotational viscometry, which allows one to evaluate the dependence of viscosity on shear rate and temperature. It was established that the studied samples are liquids with pronounced non-Newtonian properties, which are a consequence of the paraffinic nature of oil and its water-oil emulsion. The structure of nanoparticles of the dispersed phase of dehydrated oil and its emulsion is discussed and justified. Using the analytical Arrhenius–Frenkel–Eyring expression, which describes the dependence of viscosity on temperature and the physical and chemical nature of the liquid system, the results of viscometrical experiments were processed and the activation energies of viscous flow and the particle size of the inverse emulsion were calculated in the absence of a demulsifier and in its presence. Laboratory experiments have confirmed that for complete dehydration of oil well products, it is not enough to introduce only a demulsifier, but it also requires heating the emulsion to a temperature sufficient to melt and dissolve paraffin particles, which form a structural and mechanical barrier situated on the surface of the emulsion droplets.

Keywords

• oil
• water-oil emulsion
• viscosity
• viscometer
• asphaltenes
• resins