从纵波资料中提取转换横波反射系数的方法

本文提出从纵波资料中提取转换横波反射系数的方法，其理论基础为Zoeppritz方程和郑晓东AVO简化式。即利用郑氏简化式纵波和转换横波反射系数分别为偶奇函数的特点，首先对纵波反射系数沿入射角正弦方向求导，获得初步的转换横波反射系数；然后针对一次项和三次项进行“双系数校正”；最后，因郑氏简化式转换横波反射系数精度与Zoeppritz方程精度有差距，需做剩余误差补偿以获得拟转换横波反射系数，若已知速度比和转换横波子波，就可获得最终拟转换横波记录。从模型数据测试结果可知，利用该方法提取的拟转换横波反射系数与Zoeppritz精确解的拟合程度超过0.95，充分表明了该方法的有效性。

Converted S-wave reflection coefficient extraction from the longitudinal wave data

We propose in this paper a method to extract converted S-wave wave information from P-wave data.The theoretical basis of this method is Zoeppritz equation and Zheng Xiaodong AVO simplification equation.First, taking respectively reflection coefficients of P-wave and converted S-wave as even and odd functions characteristics in Zheng AVO simplification equation, the derivative of P-wave reflection coefficient along the sinusoidal direction of the incident angle is used to calculate an initial converted S-wave reflection coefficient.Then, the first and third terms are corrected by double coefficients.Finally, due to the accuracy difference between the Zheng's simplification and the Zoeppritz equation, a residual error compensation is applied to obtain quasi-converted S-wave reflection coefficient.The final quasi-converted S-wave is obtained if the velocity ratio and wavelet of the converted S-wave are known.The proposed method is validated by model data.It is satisfactory that the fitting degree of the quasi-converted S-wave and the exact solution of Zoeppritz is more than 0.95, which indicates that the proposed method is strongly feasible.