Preparation and Properties of a Novel Multi-Functional Viscous Friction Reducer Suspension for Fracturing in Unconventional Reservoirs.

Aiming at the problem that conventional friction reducers used in fracturing cannot simultaneously possess properties such as temperature resistance, salt resistance, shear resistance, rapid dissolution, and low damage. Under the design concept of "medium-low molecular weight, salt-resistant functional monomer, supramolecular physical crosslinking aggregation, and enhanced chain mechanical strength", acrylamide, sulfonic acid salt-resistant monomer 2-acrylamide-2-methylpropanesulfonic acid, hydrophobic association monomer, and rigid skeleton functional monomer acryloyl morpholine were introduced into the friction reducer molecular chain by free radical polymerization, and combined with the compound suspension technology to develop a new type of multi-functional viscous friction reducer suspension (SAMD), the comprehensive performance of SAMD was investigated. The results indicated that the critical micelle concentration of SAMD was 0.33 wt%, SAMD could be dissolved in 80,000 mg/L brine within 3.0 min, and the viscosity loss of 0.5 wt% SAMD solution was 24.1% after 10 min of dissolution in 80,000 mg/L brine compared with that in deionized water, the drag reduction rate of 0.1 wt% SAMD solution could exceed 70% at 120 °C and still maintained good drag reduction performance in brine with a salinity of 100,000 mg/L. After three cycles of 170 s