含倾斜定向排列裂隙介质纵波特征

STUDY ON THE P-WAVE CHARACTERS OF MEDIA WITH TILTED ALIGNED FRACTURE

根据Schoenberg的含裂隙介质的线性滑移模型在弱各向异性近似条件下根据Bond变换获得了含倾斜定向排列裂隙介质的弹性系数矩阵。在将含倾斜定向排列裂隙介质视为倾斜横向各项同性(TTI)介质的基础上根据弱各向异性近似条件下TTI介质纵波相速度、弹性波阻抗以及反射系数的近似解析解,研究了裂隙倾斜角对含倾斜定向排列裂隙介质中纵波相速度、反射系数以及波阻抗的影响。研究发现含倾斜裂隙介质的纵波相速度、各向异性弹性波阻抗、反射系数三个参数具有类似方位各向异性特征:入射角大的时候,显示较强方位各向异性,但是这三个参数对入射角的依赖程度却不完全相同,反射系数对入射角的依赖程度最大。

According to Schoenberg＇s linear-slip model and Bond transform,the elatica tensor of tilted transform isotropic（TTI） media is getted.Consider the media that contains tilted aligned fracture as TTI media,and then the P-wave phase velocity,PP-wave reflection coefficients and anisotropic elastic impedance of the media with fracture are studied based on the approximate analysis formula of the P-wave phase velocity,PP-wave reflection coefficients and anisotropic elastic impedance of TTI media.P-wave phase velocity,PP-wave reflection coefficients and elastic impedance of the media with fracture are all display stronger anisotropy with bigger incidence angle,but PP-wave reflection coefficients is more sensitive to the incidence angle.