方位各向异性介质的VSP资料处理

VSP data processing for azimuthal anisotropy media

地矿部石油物探研究所, 南京210014

Research Institute of Geophysical Prospecting for Petroleum, MGMR, Nanjing 210014

本文从理论上推导了二维EDA介质中旋转坐标系下的弹性波动方程,并对其进行数值模拟,获得点源激发的三分量波场振动图和正交双横波源激发用两个相互正交的水平检波器接收的四分量合成记录。利用双源四分量记录同时旋转法,对两种EDA介质中采集的四分量作分析,得到了分裂的快、慢横渡分量及它们间的时间延迟和介质的裂隙方位角。最后我们从分离的快横波记录中提取反射能量,用VSPCDP变换方法进行成像处理,其结果与地质模型相吻合。

The clastic wave equation on the rotation coordinate system for 2-D EDA media has been derived theoretically in the paper. By numeric modeling, we get the tricomponent wavefield vibration diagram impulsed by point source and the 4-component synthetic record received by two orthogonal horizontal geophones which is impulsed by two orthogonal shear sources. Through the analysis of the records from two EDA media using the simultaneous rotation methods. the split fast and slow components of shear wave, their time delay and fracture azimuth angle of media is then obtained. Finally, the reflection energy is extracted from the split fast shear data. Also, an imaging processing is conducted by VSP CDP transform method.