Development and Drag Reduction Behaviors of a Water-in-Water Emulsion Polymer Drag Reducer

As a key component of slickwater fracturing fluids, drag reducers play a critical role. Water-in-water (W/W) emulsion polymer drag reducers with the characteristics of rapid dissolution and the ability to increase viscosity are attracting substantial attention. In this work, a W/W emulsion polymer drag reducer P(AM-DMC) was synthesized via dispersion polymerization. The material P(AM-DMC) was characterized using Fourier transform infrared spectrometry, hydrogen nuclear magnetic resonance spectrometry, and environmental scanning electron microscopy. The results showed that the aqueous P(AM-DMC) solution was a pseudoplastic fluid with appreciable viscosity enhancement and shear resistance. The dissolution time of 0.1 wt % P(AM-DMC) was only 29 s. The drag-reduction rate of P(AM-DMC) reached 71.75%. The drag reducer also exhibited good temperature and salt resistance. Finally, a drag reduction mechanism was proposed. We hope that this study can broaden the application of W/W drag reducers in shale reservoir development.