裂缝各向异性介质中纵波速度的变化及其对共中心点道集叠加的影响

Variations of P-wave velocity in fractured anisotropic media and their impacts to stacking of CMP gathers

石油大学盆地与油藏研究中心, 北京102249

Research Center of Basin and Reservoir, The University of Petroleum, Beijing 102249, China

在各向同性介质中引入裂缝张量因子,可以建立不同裂缝分布模式的地质模型。利用波动方程计算裂缝各向异性介质中沿不同方向传播的纵波速度,进而建立不同裂缝分布模型的地震响应,并探讨裂缝引起的共中心点道集动校正剩余时差以及带来的沿偏移距叠加和沿方位叠加的影响。

The geologic model accounting for fractures can be constructed in isotropic media by introducing tensor factors of fractures. P-wave velocities traveled in different directions in fractured anisotropic media are calculated with wave equation. Based on the calculated results, the paper discussed the seismic responses of models with various fracture distributions, the residual moveout caused by fractures at the dynamic correction of CMP gathers, and the effects of stacking along offset and azimuths. The results show that the impacts of different fracture distribution to seismic response are varying and can not be negligible. It is also possible to predict the fracture distribution with P-wave data by established the relation between seismic response and fracture distribution.