The method of seismic attenuation and energy compensation

The energy in seismic waves will be absorbed when the waves travel in the earth,because the medium in the earth is viscoelastic. There are many kinds of energy absorption,such as geometric spreading,intrinsic attenuation,transmission losses,and energy conversion. Such energy absorptions will decrease the signal-to-noise ratio and the resolution of seismic data. In order to realize the energy compensation,many scholars both in China and abroad have tried their best to do a lot of work. In this paper,the seismic attenuation mechanism and the main factors affecting the seismic wave absorption were reviewed. Several kinds of methods of energy compensation for seismic absorption attenuation including inverse Q filtering,time-frequency analysis and inverse Q migration were emphasized. An analysis shows that these methods have their own advantages and disadvantages. The authors implement the viscoacoustic wave equation for the forward and backward wave propagation to correct the attenuation effects in reverse time migration. A numerical test demonstrates that the attenuation effects in reverse time migration can be properly compensated and the attenuation compensation can enhance the high-wavenumber components in complex geological structures. Finally,the development trend of seismic wave energy compensation is forecasted.