Pyrite has been treated in an autoclave with the use of different reducing media (CO, CO/H-2, CO/H2O) at 673 K and an initial gas pressure of 4.0 MPa. Equations of the temperature dependence of the specific heat have been derived, and the thermodynamic functions S-0(T), H-0(T)-H-0(298.15) and Theta**(T) of pyrrhotines have been calculated. The Gibbs free energy, enthalpy, entropy and equilibrium constant of pyrite reduction have been determined. An investigation has been made of the kinetics of hydrogenation of high-viscosity crude oil of the Karazhambas field (Kazakhstan) in the presence of Write. Effective values of the reaction rate coefficients and the apparent activation energies have been determined.