Experimental Investigation on a Novel Organic-Inorganic Crosslinked Polymer Gel for Water Control in Ultra-High Temperature Reservoirs

摘要

This article presents a novel organic-inorganic crosslinked polymer gel, which uses resin-silicate as the organic-inorganic crosslinker, to extend the temperature limitations of currently used polymer gels for water control in mature oilfields. The gelation performances, including gelation time, gel strength and thermal stability, were studied, and the optimum composition was selected by study of gelation performances. Results show that with increase of the concentrations of components, gelation time became shorter and gel strength was improved. And the gel system was stable after 90 days at 140 °C. The optimum composition of the gel system was selected as: 4~7 wt% resin and 2~5 wt% silicate with 0.1~0.3 wt% polymer. Meanwhile, differential scanning calorimetry (DSC) measurement was used to investigate the maximum tolerated temperature of the gel. The results showed that the chemical bonds of the gel began to break at 156 °C, which indicated that the gel can resist high temperature up to 156 °C. At last, environmental scanning electron microscopy (ESEM) microstructure and fourier transform infrared spectroscopy (FTIR) spectrum of the gel were studied to analyze the gelation process and investigate the mechanism for temperature resistance. The three-dimensional network microstructure of the resin-silicate crosslinked polymer gel was more compact and more uniform than the gel prepared without silicate. The formation of silicon-oxygen bonds (Si-O) increased the crosslinking density and temperature tolerance of the gel system.