Utilizing attenuation characteristic of seismic wave in dual-phase medium to detect oil and gas
Zhang Hui-xing1,2, He Bin-shou1, Jiang Xiao-dian1, Zhang Jin-chang1
1. Ministry of Education Key Lab of Submarine Geosciences and Prospecting Techniques,Ocean University of China,Qingdao City,Shandong,Province,266100,China;
2. State Key Lab of Coal Resources and Safe Mining,China University of Mining and Technology,Beijing City,100083,China
Abstract：In this paper under the assumption of plane wave,by solving seismic wave equation the attenuation coefficient formula in dual-phase medium was derived,and the change relationship of the attenuation coefficient with frequency was analyzed,the results show that when seismic wave propagated in the frequency range of conventional seismic exploration in dual-phase medium,the medium absorption effect existed,and the attenuation coefficient was approximately proportional to circular frequency.The attenuation coefficient was affected by seismic wave and dissipation coefficient at the same time,showing that the higher the frequency,the greater the attenuation coefficient,and the greater the dissipation coefficient,the greater the attenuation coefficient changes with frequency,the results above shows that when seismic waves passed through the dual-phase medium the corresponding energy for the different frequency component changed,with a small low-frequency energy attenuation and a large high-frequency energy attenuation,resulting in low-frequency energy enhanced and high frequency energy relatively attenuated on the energy spectrum,therefore a method by which the dual-phase characteristic or oil-gas possibility in subsurface media were inverted by utilizing the information in both the low-frequency range and the high-frequency range was proposed,the theoretical model and actual data inversion results all verified the feasibility of the method.
