The approximation of P waves reflection and transmission coefficient in viscoelastic medium and comparative analysis

With the development of oil and gas exploration,the focus of seismic exploration has been transferred gradually to lithologic and subtle oil and gas reservoir.Ideal elastic media sometimes does not explain many complex practical problems.Therefor,this article based on precision Zoeppritz equation of viscoelastic medium,according to the decomposition theory of medium,the homogeneous isotropic medium as a background,and the elastic parameters transformation and viscoelastic parameters(quality factor and decay angle) as disturbance,has derived the approximation formula of reflection and transmission coefficient of P waves to the viscoelastic interface.And using the four types of typical AVO interface model for analysis and comparison of the approximation formula of reflection coefficient,which firstly proves the correctness of the approximation formula of reflection coefficient,secondly further understands the seismic wave reflection characteristics in viscoelastic medium,thirdly provides a theoretical basis of the future application of the approximation formula.