Behavior of partially hydrolyzed polyacrylamide/polyethyleneimine reinforced with coal fly ash for preformed particle hydrogels

High water production and low oil recovery are attributable to reservoir heterogeneity, making extraction economically inefficient. To improve oil production, it is important to solve permeability issues, to allow a more uniform and efficient sweep. In recent years, several studies of preformed particle gel (PPG) have been performed reduce reservoir heterogeneity and enhance oil recovery. In this work, the effect of coal fly ash (CFA) on hydrolyzed polyacrylamide (PHPA) crosslinked with polyethyleneimine PPG were evaluated regarding thermal, rheological, and structural properties. The rheological results showed an increase in elastic behavior with the presence of CFA. Thermal analysis revealed degradation resistance of 271% with only 1.0% CFA. The swelling test proved that the presence of CFA supports the absorption of a brine solution. The results suggest a significant increase in properties assessed with small CFA contents due to a strong interaction between CFA and three-dimensional polymer networks.