Influence of halite particles on the stability and physical properties of inverse olefin emulsions

Abstract

The study of synthetic drilling fluids, consisting of inverse emulsions, became essential to the routine of the oil industry in Brazil, due to the discovery of the pre-salt carbonate reservoirs. This work aimed to analyze the incorporation of halite in the physical properties and stability of inverse olefin emulsions, which composes synthetic drilling fluids formulation. Therefore, halite was characterized in relation to its wettability, chemical and mineralogical composition. The properties of the emulsions added with halite, in the contents of 5, 10 and 15% by volume, were monitored by microscopic images, rheological tests and gravitational separation, performed before and after dynamic aging of the emulsion. The results showed that the presence of the halite particles promotes an increase in the consistency index, interfering in the viscous nature of the emulsion. In addition, dynamic aging provide changes in the flow behavior of the emulsified system, once there are increases in the behavior index, proportional to the halite content, bringing it closer to Newtonian behavior. It is also noticed that, under these conditions, the addition of this mineral intensifies the separation of the continuous phase of the emulsion, together with the emulsifying agents, especially for the contents of 10 and 15%.