Flashing is a new problem in heavy oil production technology with steam flooding. It can cause pump air locks, pump and pump tubing damage, reduced production, and other problems. A difficulty in predicting flashing parameters involves accurate calculation of the bottomhole temperature and pressure. Based on the principles of heat transfer and fluid dynamics, we have proposed the following models: a model for the wellbore temperature distribution, a model for the stress distribution, a model for calculating the partial loss of pressure when the fluid flows through a fixed valve, and also a model for calculating the parameters for steam flooding of heavy oil, taking into account corrections for the influence of the parameters of the oil — water mixture on the steam critical temperature vs. pressure curve. Taking into account the nature of the fluid, the moisture content, the temperature and other wellbore parameters, the model permits real-time monitoring of flashing in the pump. Experiments were conducted on Jin 45-22-K281 wells. We performed a comparative analysis of the calculated and experimentally measured values. We have shown that the model for calculating flashing parameters is sufficiently accurate for the bottomhole fluid conditions. Analysis of the factors influencing the flashing effect may be useful for providing a theoretical basis for steam flooding parameters.