Emulsion-based drilling fluids: Rheological properties preservation facing changes on the temperature, pressure and dispersed phase

Abstract

The biodiesel transesterification reaction generates crude glycerol as a by-product, which has been excessively generated due to the growing production of this biofuel. The possibility of allocating this low value-added waste to applications would solve several problems, especially regarding the need to dispose of this material. In this sense, the use of crude glycerol in olefin-based inverse emulsion fluids is something new in the literature. However, its performance in drilling fluids must ensure that the fluid's rheological properties are achieved. For this purpose, the plastic viscosity, yield stress and thixotropy of olefin-based fluids were studied, varying the temperature, pressure and the composition of the dispersed phase (sodium chloride brine (NaCl), crude glycerol and pure glycerol). A 23 factorial design was also carried out to assess whether the dispersed phase type, pressure and temperature variables affect the rheological properties of these fluids. The results showed that crude glycerol maintains the rheological properties of the conventional NaCl brine fluid even with changes in temperature and pressure, enabling the use of this industry waste for this type of application.