Simulator of Thermodynamics During Washing and Cementing ﷯ The simulator allows computing temperature changes in drilling tubes, annular space and surrounding rock during washing and cementing. It accounts for varied geometry of drilling tubes and borehole, mud properties and volumetric rate, thermophysical properties and geothermal coefficient of rock surrounding the borehole, presence of formation with different thermophysical parameters of the rock. The simulator allows quick and precise determination of the temperature distribution in the system vs. time, depending on a number of system parameters. It can prevent a number of dangerous complications during washing and cementing and takes into account the influence of temperature on mud and cement.