地震分频解释技术在河道砂预测中的应用

Application of Spectral Decomposition Technique in Fluvial Sand Body Prediction

地震资料分频处理技术是一种比常规地震属性识别储层更有效的方法。该方法将一定时窗内地震反射波通过离散傅里叶变从时间域换转换到频率域,用转换后的振幅谱和相位谱识别薄储层的厚度变化和边界。通过该技术可以对地震资料中所有单频信号进行有针对性的分析,已经证明是一种具有较高可信度的技术。针对胜利油田老河口油田老168井区馆陶组河道砂油藏厚度薄、横向变化大的地质特征,本文运用分频处理技术对该井区馆陶组地层砂体分布进行预测,并对储层非均质性进行了分析,经钻井证实,预测结果与实际情况十分吻合。

Spectral decomposition is a more efficient method to identify reservoir than seismic attribute. It transforms the time domain of the seismic data in a certain time windows into the frequency domain by Discrete Fou- rier Transform. The reservoir thickness changes and boundary can be identified and imaged by the new amplitude spectrum and phase spectrum. The DFT computes an amplitude value at every hertz from the beginning frequency to the ending frequency, it has a highly deserved reputation for being safe and reliable . The fluvial sand body of Guan- tao formation in the Laohekou Oilfield is characteristic of thin thickness and severe variety in lateral direction, The thickness and geologic discontinuity and distribution of the sand body are predicted by the method of spectral de- composition. The results coincide well with actual drilling data.