MULTI-COMPONENT GAUSSIAN BEAM MIGRATION BASED ON ATTENUATION COMPENSATION

Elastic waves are affected by viscoelasticity during the propagation through the Earth, especially in highly attenuated areas with hydrocarbon reservoirs, resulting in energy attenuation and phase distortion, in turn resulting in low seismic imaging accuracy. To address the negative effects of attenuation, we propose a multi-component Gaussian beam migration method based on attenuation compensation. This method can restore energy decay and correct phase distortion and ultimately improve imaging resolution. This paper uses the source-normalized cross-correlation imaging condition to obtain the imaging equations for elastic media based on Gaussian beams and Green's functions in elastic media. Then we derive the complex-valued traveltimes of Gaussian beam in viscoelastic media by using the complex-valued velocity of Gaussian beam in viscoelastic media. Finally, we obtain the multi-component Gaussian beam migration imaging method based on attenuation compensation by replacing the traveltimes of the elastic wave Gaussian beam with complex-valued traveltimes and reversing the sign of these terms. Compared with conventional acoustic migration methods, the method in this paper makes full use of S-wave, which is more sensitive to oil and gas reservoirs. In addition, compared with isotropic elastic Gaussian-beam migration, the amplitude recovery of this method is more advantageous. Therefore, the method in this paper is eminently suitable for imaging high attenuation areas with fluid, which aids in investigating oil and gas reservoirs.