Abstract: Aiming at the difficulty of oil lifting caused by the formation of multi-phase mixed fluid in deep heavy oil during wellbore lifting, the calculation model of oil-gas-water three-phase pressure drop is derived and revised based on the experimental data of high temperature and high pressure by using high temperature and high pressure wellbore simulation device. The fitting degree between experimental data and the model is over 0.98, and the gas-liquid distribution under different gas-liquid ratios is obtained, which is C_og value. The experimental results show that the C_og value of bubbly flow is the smallest, the degree of gas dispersion is high, and the gas-liquid mixture is evenly distributed, which has the most significant effect on reducing the total pressure drop of gas-liquid. Therefore, keeping the gas-liquid flow pattern in the bubble flow zone is more conducive to production. The study on the influence of flow pattern on gas-liquid total pressure drop provides a new idea for accurate prediction of lift-up pressure drop in heavy oil recovery.