Enhancing the Viscoelasticity and Proppant-Carrying Ability of Viscous Slickwater via Hydrophobic Association by Dispersed Microemulsions

To improve the proppant-carrying ability of fracturing fluid without sacrificing its friction reduction performance, a microemulsion-aided viscous slickwater is developed with various concentrations of hydrophobically modified polyacrylamide (HAPAM) and 0.1 wt % dispersed microemulsion (DME). Electrostatic repulsion between the anionic–nonionic interfaces in DME and the negatively charged hydrophobic side chains of HAPAM promotes the formation of a stable three-dimensional network structure under low shear rates. This structure enhances elasticity and enables an effective proppant suspension. At high shear rates, the fluid maintains sufficient viscoelasticity for effective proppant transportation. The friction reduction tests show a synergistic friction reduction effect of DME and HAPAM under low Reynolds numbers. Rheological tests show that the crossover point (G′ = G″) shifts to the lower shear rate region with the DME addition, indicating enhanced elasticity favorable for proppant suspension. Dynamic proppant transport experiments further confirm that the presence of DME can significantly reduce the proppant bank area, indicating an enhanced proppant-carrying ability. Laboratory results reveal that the new DME-aided viscous slickwater performs both promising friction reduction and proppant transport abilities, successfully combining the advantages of conventional slickwater–water and cross-linked gel.