Experimental Exploration on the Adsorption Law of Polyacrylamide Derivatives on Quartz Surface

Polymer adsorption has become a key factor of permeability damage in tight reservoirs. Understanding the adsorption law of polymer on rock surface is helpful to reduce the permeability damage caused by polymer adsorption in hydraulic fracturing. In this work, the adsorption law and influencing factors of polyacrylamide derivatives on formation rock were studied in detail. Quartz is used to replace real formation rocks. The static adsorption capacity of acrylamide copolymers on quartz surfaces under different conditions was tested. First, the phenomenon of saturated adsorption of polymer was found in the experiment. Second, monomer type greatly affects the adsorption capacity of the copolymer. Experimental results showed that the adsorption capacity of polymer is P‐MPS < PAA < P‐NVP < P‐MAA < P‐EMA. Thirdly, temperature increases can inhibit the adsorption capacity of different polymers. Real rock samples will increase the adsorption capacity of polymers, but the adsorption law remains unchanged. This showed that it is feasible to use quartz instead of real rock in this study. Besides, hydrolysis is also a critical factor affecting polymer adsorption. It can inhibit the adsorption of polymer on quartz, but the viscosity reduction caused by hydrolysis must be considered in the practical application. Therefore, it should fully combine the formation conditions and the molecular structure of the polymer when we study permeability damage caused by polymer adsorption, according to the experimental study.