Chemical enhanced oil recovery (EOR) methods are alternatives to increase oil production in mature reservoirs. However, the presence of EOR chemicals in the produced water may impact the separation of gas-water systems in oil platforms. The present work aims to evaluate the impact of polymers, surfactants, inorganic salts, and their interactions on gas holdup in a 32.1-cm-diameter semi-batch bubble column over a range of superficial gas velocities ranging from 0 to 19 cm/s. It has been confirmed through physical-chemical analysis that synthetic produced water containing salts, polymers and organic surfactants is non-Newtonian with low surface tension. Results have shown that both salt and surfactants increase gas holdup regardless of superficial gas velocity, while the effect of polymers depends on superficial gas velocity. This work also innovates by showing how interactions between EOR chemicals and salinity affect transition gas holdup and superficial gas velocity between different flow regimes. Overall results shed some light on how the chemical composition of EOR effluents affect gas holdup and flow regime as a function of a wide range of superficial gas velocities and therefore contributes to the development of gas-liquid systems.