ИСТИНА

The effect of temperature changes on the velocity of longitudinal and shear waves of water-saturated sandstone samples is considered. The presence of water affects only the velocity of the longitudinal waves and does not affect the velocity of the shear waves, which caused a different nature of their change when the temperature increases at various effective pressures. All elastic modules decrease with increasing temperature, only the Poisson's ratio tends to increase with increasing temperature. A decrease in rock strength can be expected with increasing temperature and in particular a decrease in shear strength, which may look like an increase in the plasticity of rocks, which is often accompanied by an increase in Poisson's rate. Obtained dependencies of elastic velocities and modules on temperature can be used both for estimation of changes of stress-strain state of formation, and for estimation of its temperature during geodynamic monitoring at thermal effect on oil and gas fields.