Abstract

Studying the data derived from oil and gas wells showed an increase in absorption and phase velocity dispersion of seismic waves  in the oil and gas reservoirs. This is explained by  the fact that an oil and/or gas-charged layer often demonstrates heterogeneous lithology and is called nonlinear elastic medium . Addition, there are other causes which are thermodynamic instability of complex mixtures and the phase transition (Gas/liquid) of fluid when seismic waves pass through. These effects are related to the nonlinear seismic elasticity and can be used in various stages of oil and gas exploration.