Abstract
To tackle the challenges of high viscosity, poor fluidity, and low recovery rates in heavy oil, a novel comb-like polymer viscosity reducer (GO-Z) based on nanographene oxide (GO) was developed. GO was first functionalized with a silane coupling agent and then grafted with long-chain alkyl (C16DMAAC) and polyether (APEG-8) groups. The results show that GO-Z exhibited superior emulsification, dispersion, and viscosity reduction properties under microagitation conditions (simulating the low-shear conditions of real reservoirs), achieving over 94% viscosity reduction at a concentration of 0.3 wt %. Physical simulation flooding experiments further demonstrated that GO-Z effectively improved heavy oil recovery at various injection rates, with the highest increase reaching 11.61%. This study opens up a clear and promising path for the application of functionalized GO in the emulsification and viscosity reduction of heavy oil cold production.