Preparation of adaptive bifunctional reconfigurable polymers and their sand carrying and drag reduction behaviour

Abstract

In order to solve the problem of drag reduction at the front end of shale fractures and sand carrying at the tail end with increased viscosity, the molecular dynamics simulation (MD) method was used to design polymer molecules and simulate the steric resistance, interaction potential energy, mean square displacement, and radial distribution function of the polymer. The polymer AM-AMPS-LMA-DiC₁₂AM (ASLC12) with better solubility, diffusion, and resistance reduction potential was obtained and synthesized. By scanning electron microscope (SEM) and viscoelastic analysis, ASLC12 has a stable mesh structure, good viscoelasticity, and shear resistance, and the mesh structure formed by it is in a dynamic equilibrium state of fracture-reorganization under shear. We then analyzed the drag reduction, sand carrying, and salt resistance of ASLC12. When the concentration of ASLC12 is 0.09%, the sand-carrying requirement is satisfied. When the concentration is 0.05%, the drag reduction rate can reach 74.1%, and the resistance reduction rate of ASLC12 in salt ion solution can still reach more than 62%. This shows that the polymer ASLC12 has better sand carrying, drag reduction, and salt resistance.