Acrylamide-Based Fracturing Fluid With Adjustable Viscosity Prepared by Two-Phase Dispersion Polymerization for Shale Gas Development

Slickwater fracturing technology as a key means of the efficient shale gas development, relies on polymer molecular chains to reduce turbulent vortices and suppress radial flow fluctuations, thereby lowering fluid frictional drag and enhancing axial transport efficiency. However, conventional linear polymers fail to achieve the “shear thinning-static thickening” of the rheological response, still facing technical bottlenecks such as insufficient viscosity and poor flexibility in flow state transition during deep applications, which limits their fracturing effectiveness in deep shale gas reservoirs. Herein, we developed a tetrameric acrylamide-based polymer, polygamas (AM/AMPS/AA/SMA), via two-phase dispersion polymerization for deep shale gas development. Its hydrophobic groups form a dynamic physical crosslinking network, significantly enhancing tackifying ability. By adjusting the concentration, polyAMAS can freely switch between low-viscosity slickwater and high-viscosity gel fluid, effectively resolving the conflict between friction reduction and proppant-carrying performance. Static proppant-suspension tests showed that under high sand ratio conditions, the solution's settling rate was 0.174 mm/s, meeting the requirements of real-time mixing fracturing operations. The developed acrylamide-based emulsion, integrating friction reduction, proppant transport, and viscosity enhancement, effectively overcomes the key technical challenge of balancing high-efficiency friction reduction and stable proppant-carrying in conventional fracturing fluids, demonstrating significant potential for deep shale gas development.