A rapidly dissolving W/O polymer emulsion system for integrated acid thickening and drag reduction

An instant dissolving W/O polymer prepared via reverse-phase emulsion polymerization. • An ultra-high acid resistance polymer formed from water-soluble hydrophobic monomers. • Integrated application for drag reducing and acidic thickening. • Quantum chemistry is used to clarify the mechanisms of dissolution and acid tolerance. Despite the considerable potential of multistage alternating acid fracturing Technique for unconventional tight reservoir stimulation, the integration of acid-thickening and drag-reduction functions within a single additive remains challenging due to the slow dissolution of gelling agents, poor acid resistance of drag reducers, and compatibility issues among multiple chemical additives. Herein, a multifunctional polymer emulsion (PAADT) was rationally designed using a hydrophobic monomer (AT-100) and a high-charge-density symmetric cationic monomer (Dimethyl Diallyl Ammonium Chloride, DMDAAC) to overcome these limitations. PAADT completely dissolved in water and concentrated HCl within 120 s and 330 s, respectively, while retaining viscosity stability for over 120 h and demonstrating exceptional tolerance to multivalent ions. Quantum chemical calculations, including LogP, independent gradient model based on Hirshfeld partition (IGMH), and electrostatic potential (ESP) analysis, revealed that the synergistic effect of polymer-water interactions and electrostatic repulsion governs the dissolution behavior and acid-salt resistance of PAADT. This work establishes a structure–property relationship between monomer architecture and macroscopic performance, providing a molecular design strategy for developing multifunctional polymers for complex environments. Download: Download high-res image (246KB) Download: Download full-size image