Solution properties and seepage characteristics of a dendritic hydrophobically associating polymer.

This study provides guidance for the effective application of dendritic hydrophobically associating polymer (DHAP) solutions to establish flow resistance in porous media. The solution properties (viscoelasticity, rheological properties, hydrodynamic size, and static adsorption capacity) of a DHAP were evaluated. The seepage characteristics of the porous medium were also studied. The effects of solution concentration, the permeability of the porous medium, and the injection rate of the polymer solution on the establishment of flow resistance were analyzed. The results showed that the elastic modulus of DHAP was dominant over the viscosity modulus, and the rheological behavior and hydrodynamic size were not greatly affected by the solution concentration. The adsorption characteristics of DHAP on the porous medium indicated multimolecular-layer adsorption. The equilibrium adsorption capacity was approximately 1100 μg/g. When DHAP at a concentration of 2000 mg/L passed through a 2500-mD porous medium at a flow rate of 0.1 mL/min, the injection pressure increased with cumulative injection volume, and it was difficult to achieve injection equilibrium. Increasing the injection rate caused the injection pressure to increase more quickly, making it easier to reach injection equilibrium. As the injection velocity increased, the resistance factor of the polymer solution in the porous medium first decreased and then became stable. Thus, high-speed DHAP injection reduced the resistance factor in the porous medium, while low-speed DHAP injection resulted in higher flow resistance. [ABSTRACT FROM AUTHOR]