井间地震资料深度域合成记录的制作方法

在对深度域的井间地震资料进行地质解释时,用于层位标定的合成记录必须是深度域的。对深度域的地震资料合成记录制作方法进行了探讨。总结归纳深度域合成记录制作过程应包括:(1)利用声波、密度等测井曲线进行层位划分并建立深时关系,根据多层介质反射系数的波动方程推导公式,求取频率域的反射系数;(2)对时间域的井旁道记录利用同态反褶积方法提取地震子波,得到频率域的子波谱;(3)利用频率域褶积模型计算合成记录,作反傅里叶变换得到时间域合成地震记录,再根据时深关系求出每个时域采样点对应的深度点,按照所要求的深度采样间隔进行重采样,得到深度域合成地震记录。应用实例表明,利用该方法制作的合成记录与井旁道的吻合程度较高,可以用于井间资料的层位标定。

Preparative method of synthetic seismogram of crosshole seismic data in depth domain

When crosshole seismic data in depth domain were interpreted geologically, synthetic seismogram used to identify seismic horizons must be in depth domain. The procedure consists of the following steps: Firstly, classify horizons by acoustic wave, density data and so on, build up depth-time relationship, and calculate reflection coefficients in frequency domain through the reflectivity formula derived from elastic wave propagation equation of multiple horizontal media. Secondly, extract seismic wavelet from borehole side seismic trace by cestrum method to get wavelet spectrum in frequency domain. Thirdly, calculate synthetic seismogram by convolution model in frequency domain, and get synthetic seismogram in time domain by anti-Fourier transform, and then request the corresponding depth dot of every sample position in time domain, and resample according to the needed sample interval in depth domain to get synthetic seismogram in depth domain. Through the practical application, the synthetic seismogram made by this method fits greatly borehole side trace, and may use reliably in horizon identification of crosshole data.