The development of gas deposits at the final stage is usually complicated by watering production wells. With the advent of water in the formation product, the gas production rate decreases due to the decrease in the gassaturated thickness of the reservoirs and the increase in pressure loss during movement of the liquid-gas mixture in the wellbore and flow lines as compared to the movement of gas only. Well operation is gradually becoming unstable, periodic with the subsequent cessation of natural flowing. The methods of operation of flooded wells are characterized. The use of the gas-lift method for the operation of flooded gas wells in depleted gas fields is justified. The effect of tubing diameter, wellhead pressure and water factor on the parameters of gas-lift operation of flooded wells is investigated. The research is carried out using the improved technique proposed by the authors and the PipeSim program for hypothetical (simulated) well conditions. The studies performed are presented in the form of graphical dependences of the production rate of reservoir gas, the minimum required gas production rate for the liquid to be taken from the bottom of the well to the surface, lift gas flow rate and bottomhole pressure on wellhead pressure, diameter of tubing and water factor. The research results indicate a significant coincidence of the values of the calculated parameters of the gas-lift operation of the watered well according to the proposed methods and the PipeSim program. Using the research results, it is possible to select the optimal diameter of the tubing string and evaluate the value of formation gas flow rate and gas-lift flow rates for various values of water factor and wellhead pressure