Synthesis and analysis of drag reduction performance of the temperature-resistant polymer slickwater for high temperature reservoirs

Abstract

Slickwater has been extensively utilised in deep reservoir fracturing owing to its excellent drag reduction performance, and the polymer drag reducer is the core of slickwater. However, polymer drag reducers may degrade at high temperatures, which limits the application of slickwater in high temperature reservoirs. To increase the temperature resistance of slickwater, a novel temperature-resistant polymer drag reducer was chemically synthesised through free-radical polymerisation using acrylamide (AM), acrylic acid (AA), 2-acrylamide-2-methylpropyl sulfonic acid (AMPS) and N,N-dimethylacrylamide (DMAA). The introduction of temperature-resistant monomers substantially increased the thermal stability of the drag reducer. The rheological measurements revealed that the aqueous polymer solution was a pseudoplastic fluid with good viscoelasticity and thickening properties. At 110 °C, the drag reduction rate of 0.03 wt% polymer aqueous solution could reach 72.57 %, and the drag reduction retention rate was 96.69 % when compared with that at 25 °C. The drag reduction performance was evaluated in relation to displacement, concentration, temperature, pipe diameter, and salinity. Simultaneously, the proportion of factors influencing the drag reduction performance was analysed. Finally, a drag reduction mechanism was proposed. This study is expected to extend the application of slickwater in high-temperature reservoir development.