Preparation and Application of Superhydrophobic Multifunctional Drag Reducing Agents for Slickwater Fracturing Fluids

At present, conventional smooth hydraulic fracturing fluid systems generally have various functions such as drag reduction, sand carrying, salt resistance, and temperature resistance, but none of them have considered achieving reservoir protection by changing the surface wettability of the reservoir. Therefore, in this paper, a superhydrophobic multifunctional fracturing fluid drag reducing agent, named SHJZ-1, was synthesized using acrylic acid, acrylamide, self-made material 2-acrylamido-2-phenylethanesulfonic acid, and hydrophobic modifier as raw materials. The structure of the synthesized drag reducing agent was characterized by infrared spectroscopy, and its performance was comprehensively evaluated through various methods such as high-temperature and high-pressure core dynamic damage evaluation system, contact angle measurement instrument, Hack rheometer, and closed pipeline friction tester. The results show that the drag reducing agent SHJZ-1 had a short dissolution time and rapid adhesion. When the salinity of saline water reaches 40000 mg/L, the drag reduction rate of 0.5% SHJZ-1 solution was about 68%. The 0.15% SHJZ-1 solution can still achieve a drag reduction rate of over 70% after high-temperature aging at 140 ℃. Furthermore, the core treated with 1.3% SHJZ-1 solution exhibited superhydrophobic effect, with a core contact angle of 151.21°. Additionally, the average permeability damage rate of the core caused by this drag reducing agent solution was only 11.6%. The super hydrophobic multifunctional smooth hydraulic fracturing fluid system has been successfully applied on site in the HX-1 well. In fracturing engineering, the performance of smooth hydraulic fracturing fluid is relatively stable, and the production after fracturing is increased by more than 10% compared to the adjacent well. The effect is significant, achieving the goal of improving quality and efficiency.