摘要
本文从各向异性介质的弹性波波动方程出发，推导出各向异性介质界面上36个反射和透射系数的计算公式。裂隙介质中P－P波反射系数的计算结果表明：在垂直裂隙与方位各向同性介质所构成的界面上，P－P波反射系数（绝对值）在平行于裂隙方向达到极大值，在垂直干裂隙方向出现极小值。裂隙倾角会影响P－P波的方位AVO特征，倾角越小，AVO随方位的变化越小。在由非水平裂隙构成的界面上，P－P波反射系数会出现更多的极值而变得较为复杂，且不能直接指示裂隙走向。纵波方位AVO特征与裂隙方位、倾角以及密度密切相关。
36 formulae of reflection and transmission coefficients on anisotropic interface are derived from elastic wave equation in anisotropic medium.The computation result of P-P wave reflection coefficients in fractured mediumsays that on an interface consisting of vertical fractures and azimuthal isotropic medium, P-P wave reflection coefficient (absolute value ) comes up to maximum in direction paralleling fracture, but gets minimum in direction perpendicular to frac-ture. Dip angle of fracture influences the AVO characteristic of P-P wave, minor dip angle resulting in gentler AVO phenomenon. On the interface where there are non-horizontal fractures, reflection coefficient of P-P wave has more extrema to show complexity and to fail to directly indicate fracture strike. In a word, the az-imuthal AVO characteristic of compressional wave is cl0se related to the azimuth,dip angle and density of fractures.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
1999年第3期260-268,共9页
Oil Geophysical Prospecting
关键词
AVO
各向异性
裂隙
油气藏
油气勘探
地震勘探
azimuthal AVO, anisotropy, fracture, reflection coefficient, wave equation, interface
