从阵列声波测井波形处理地层纵、横波时差的新方法

The new method of processing the slowness of P and S-wave from waveforms of array sonic logging

阵列声波测井波形中包含丰富的地层纵、横波速度信息.如何从这些波形中提取出这些速度信息,得到比较准确的地层纵、横波时差是资料应用人员非常关心的问题.目前,最常用的纵、横时差处理方法是STC———慢度—时间相关法.该方法只有在波形的速度频散不严重时比较有效.而井内声波传播的基本特征是具有频散特征.利用Ma-trix pencil方法可以求出阵列声波测井波形的二维谱.借助于波形的二维谱,本文给出一种求地层的纵、横波时差的方法.本方法充分利用井内声波传播的规律,有效地减小了频散对纵、横波时差计算的影响,得到的纵、横波时差值精度比较高.

From array sonic logging data, the 2D spectrum can been obtained by Matrix pencil method. Using the spectrum, the slownesses of P-wave S-wave and Stoneley wave are calculated by two new methods. They are called phase velocity and group velocity in this paper. The characterization of dispersion for P-wave and S-wave are used in this method. So the accuracy of the slowness of P-wave and S-wave is higher than STC.