Research On Methods Of Quality Factor Extraction And Compensation For The Attenuation Based On VSP Seismic Data

the viscosity of medium call the attenuation of amplitude, decrease the apparent frequency,at last cause dissipate energy of seismic wave in subsurface spread. This is detrimental to the subsequent processing. Because it is hard to obtain high resolution image directly. Considering the properties of seismic wave propagation in viscoelastic media, research on the corresponding processing method can effectively improve the quality of seismic data. In this paper, the numerical simulation method of viscoelastic model and the methods of Quality factor extraction and compensation for the attenuation were mainly researched and studied.The analysis of the factors affecting the seismic wave attenuation fromtheory, the viscoelastic medium model and seismic wave attenuation dispersion models were analyzed and compared. On the basis of derivation of the Zoeppritz equations of viscoelastic medium, analyzes the propagation and the reflection characteristics of seismic wave. This paper studies the viscoelastic medium ray method and finite difference forward simulation method, simulation of a viscoelastic VSP shot record.Through the analysis of the forward characteristics of wave field, to verify the reliability of the quality factor extraction method. Design of the quality factor Q of the improved spectral ratio method, write the procedure for the method of extracting quality factor Q based on VSP data. Then based on the principle of inverse Q filtering compensation method, compiled the seismic data compensation program. Analysis and processing of model and real data show that, the improved spectral ratio method can calculate the equivalent quality factor, through inverse Q filtering method can effectively compensate for the seismic data. The effective band width seismic data has been extended, amplitude compensated, events become clearer, resolution is significantly improved.