Slow Kinetics of viscoelastic properties of oil at low-frequency shear vibrations

The results of experiments on the observation of the slow evolution of viscoelasticity moduli of crude oil are presented. Measurements were carried out continuously for 72 h at frequencies of 0.5, 5, and 50 Hz at different temperatures. Based on the Boltzmann statistical approach to determination of the velocity of transition into an equilibrium state, a model differential equation describing slow kinetics of variations in the internal medium parameters is derived. As distinct from the accepted exponential time dependence, the slow kinetics is shown to yield a logarithmic time dependence of perturbation damping.