用复分析检测垂直裂隙横波分裂的应用研究

The application study of complex analysis in detection of shear wave splitting due to vertical fractures

在三分量地震勘探中，如果取径向与横向2个水平分量作为复分量的实部和虚部，就可将这2个分量的数据由常规奋卡尔坐标系变换到极坐标系，从而计算出瞬时振幅、瞬时相位和瞬时频率，我们把这种方法叫做水平两分量复分析。复分析所提供的瞬时信息可能有助于检测垂直裂隙引起的横波分裂，也有助于地层解释。本文将首先介绍由叠后径向和横向2个水平分量构成的复分量的复分析原理和方法，然后通过合成数值例子说明垂直裂隙横波分裂的三瞬特点，最后讨论1个用复分析检测横波分裂的实际例子。

In tricomponent seismic prospeting, if we take the two horizontal components as the realpart and imaginary part of a complex component, the data of the two componens can then be transformed driconventional Cartesian coordinates to polar coordinates. Thus their instantaneous amplitude,phase, and frequency can be computed. We call this technique horizontal two-comoponent complex anaysis. The instantancous information may be hepful to the detection of shear wave splitting due to verticalfractures, and also helpful to the stratigraphic interpretation. This paper firstly introduces the principleand procedure of the complex analysis for the complex compoent constituted with poststack inline andcrossline components, and then demenstrates the features of the three instantaneous parameters for theshear wave splitting due to vertica fractures through a synthetic example. Finally, a real example of detecting shear wave splitting by complex analysis is discussed.