New Holistic Approach to Prevent Emulsion Formation from Fracturing Fluids

Abstract One of the significant challenges faced by the oil industry in shale formations is the excessive production of emulsified fluids during the load recovery of the fracturing fluids. These emulsion-related problems create substantial difficulties in the treatment and transportation of crude oil. In certain shale regions today, the use of non-emulsifiers when used in the fracturing fluids was initially intended for crude oils characterized by high concentrations of resins and asphaltenes. However, recent findings indicate that managing emulsion problems has become more difficult in crude oils with elevated levels of paraffins and condensates. Conducted under both ambient and elevated temperature conditions, this study aims to examine the influence of over 21 non-emulsifiers, along with surfactant and nano-surfactant formulations, on the emulsion separation between fracturing fluids and high paraffin crude oils sourced from the Permian basin and condensates from the Haynesville. This investigation focuses on the load recovery of completion fluids formulated with anionic and cationic friction reducers (copolymers and terpolymers of polyacrylamides), in either Emulsion Polyacrylamide (EPAM) or as a slurry of dry friction reducers (either oil or water-based) forms. Additionally, the study assesses how interfacial tension (IFT), viscosity, and viscoelastic properties can enhance emulsion separation. The impact of surfactants employed as non-emulsifiers is often quite restricted, particularly when used in conjunction with Anionic EPAM at low salinity levels (less than 5000 mg/L). However, efficiency can be significantly enhanced when these non-emulsifiers are paired with slurry-based friction reducers, depending on their specific formulation. Interfacial tension measurements for surfactants interacting with these oils indicate that a higher IFT value correlates with improved emulsion separation in Paraffinic Permian oil. Unlike conventional approaches for assessing the effects on non-emulsifiers, this Holistic approach has enabled a reduction or complete removal of de-emulsifiers as proven in the field during the load recovery process of frac fluids in the separators of upstream crude oil production equipment.