Polymer gel has been established as a water shut-off control agent for improved oil recovery. The role of the polymer gel in conformance control is to divert injected water from high permeability to low permeability zones of the reservoir. This paper presents a series of core flooding tests performed to investigate the propagation, blocking capability, permeability reduction and diverting performance of various mixtures of polymer gels at simulated reservoir condition. In this particular study, a core flooding scheme with crossflow effect using composite core has permeability contrast. Core flooding test with crossflow effect simulates reservoirs with communication between reservoir permeability layers. Experimental results show that PAM/PEI polymer gel reinforced with solid silica NP has been proven to provide satisfactory gel strength to divert water flow, thus recovering an additional 24 of oil. This reinforced PAM/PEI polymer gel tends to recover more trapped oil compared to weakened PAM/PEI polymer gel without solid particles. These results give better understanding and provide additional knowledge of strengthening gel by addition of solid particles, which could be the remedy for the weakened polymer gel. © 2022, The Korean Institute of Chemical Engineers.