Polyacrylamide (PAM)/polyethyleneimine (PEI) gels doped with graphene oxide (GO) were prepared. Their structure and properties were systematically studied by X-ray diffraction (XRD), Fourier transition infrared spectrum (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and rheological experiments. The results showed that the graphene oxide (GO) nanosheets were significantly involved in the cross-linking reaction between the main agent (PAM) and the cross-linker (PEI), serving as multi-functional cross-linker and effective reinforcing nanofillers. Increasing the main agent and cross-linker content, the strength of gels was enhanced effectively. The GO could effectively adjust the strength and the gelation time to exhibit characteristics of weak gel, thanks to the improved three-dimensional honeycombed structure with controllable pore size. The DSC confirmed that the PAM/PEI/GO gel exhibited excellent thermal stability and did not dehydrate above 170 °C. This work provides theoretical support for further optimization of polyacrylamide gel used in ultra-deep and high-temperature reservoirs for water control.
