An Introduction of Novel Additive to Enhance the Performance of the Slick Water Formulation to Improve Phase Behavior and Regain Permeability

Slick water fracturing fluid is characterized by the incorporation of a specified quantity of proppants and other additives, including surfactants, friction-reducing agents, and anti-swelling agents in the aqueous medium. Since the early 1950s, slickwater has been employed in the development of oil and gas reservoirs. The primary method for hydraulic fracturing of unconventional shale reservoirs involves the use of slick water formulations. The efficacy of slick water is evaluated based on the concentration of friction reducers and other chemicals, and their influence on viscosity, surface tension, aging tests, and regain permeability tests. It is essential to ensure a clean and clear phase behavior of high viscosity friction reducers (HVFR) formulations to reduce damage to regain permeability. A typical high viscosity friction reducer (HVFR) formulation consists of friction reducer polymer, surfactant, biocide, clay stabilizer, and breaker, all incorporated into water to achieve the desired viscosity, surface tension, and regain permeability specifications. In certain brine compositions that contains significant amounts of divalent cations HVFR formulations may become unstable in high temperature applications. In such cases, adjustments to the formulations are necessary, and new additives may need to be introduced to maintain a clean and effective breaking of the slick water. Key variables affecting the performance of the system include surface tension, viscosity, mixed micellar formation, rate of polymer scission, and deflocculation of polymer particles. In this study, we propose a novel additive that preferentially migrates to the interface, effectively reducing the surface tension below 25 mN/m. The conventional system, composed of a friction reducer, surfactant, clay stabilizer, biocide, and breaker, demonstrated unstable phase behavior after aging the sample for 24 hours at 270°F. Root cause analysis, screening, and elimination methodologies were employed to identify the performance issue in the HVFR slurry. The inclusion of the novel additive enhanced the performance of primary surfactants and prevented the broken friction reducer polymer from flocculating, thereby keeping it well suspended. Additionally, the surface tension of the entire formulation was reduced by up to 5 mN/m with the addition of one-tenth of the novel additive concentration compared to the primary surfactant. The reduced surface tension enhances the penetration of the HVFR in the formation as well as retrieval of the fluid during the flow back, in turn giving less permeability damage. This study introduced a novel additive to enhance mixed micelle formation, improving polymer phase behavior and HVFR flowability in porous media. The additive reduced permeability damage and increased regain permeability by up to 7% compared to conventional HVFR formulations. This high-temperature HVFR formulation minimized phase separation of the friction reducer polymer after 24-hour aging and kept broken polymer particles suspended. Overall, the novel additive significantly improved HVFR performance for high-temperature and high-salinity slick water applications.