Experimental research of high strength thermally stable organic composite polymer gel

Abstract

Polymer gel has been successfully applied for enhanced oil recovery (EOR) in heterogeneous reservoirs. A novel composite polymer gel was developed based on amphiphilic polymer, resorsinol/hexamethylenetetramine, silica dioxide (SiO2) and surfactant under the conditions of temperature from 60 °C to 100 °C and total salinity of 51,984 mg/L, Ca2+ 3308 mg/L and Mg2+ of 1820 mg/L. It was characterized in terms of gelation time, gel strength, morphology, long term thermal stability and effect of pH. The effect of different component concentrations in the properties of bulk gelation was investigated. The microstructure of the conventional (organic) gel and novel composite gel were studied by electron scanning microscopy (SEM), which provides insight into the mechanism of gel strength. The organic polymer gel was compared with the composite gel. The gelation time and gel strength was studied varying the concentration of nanoparticles, cross linker and polymer. The gel strength was evaluated by vacuum pump method. The composite gel was prepared by using organic cross linker and addition of SiO2with surfactant, showed prominent results and proved to be of good strength with optimum concentration of SiO2. The composite gel also showed good thermal stability with negligible syneresis at 60 °C for 90 days at pH = 8.0–8.5,which showed that composite polymer gel results in better thermal stability than conventional polymer gel and can be successfully injected into heterogeneous reservoirs for EOR.