An approach to predictions of position and size of hydrate plugs inside gas wells has been proposed. It is based on the mathematical model of steady non-isothermal flow of real gas in tubes and an algorithm of calculation of equilibrium conditions of hydrate formation. The proposed approach includes the following steps. 1) Numerically solve the system of ordinary differential equations to find the distributions of pressure and temperature along a particular well. 2) Represent the results of calculations as connection between pressure and temperature. 3) Find the intersection of this function with the calculated or experimental equilibrium curve for a particular natural gas. 4) Find the depth of well from the results of numerical solution.