分频技术在曲流河储层预测中的应用

Aplication of Spectral Decomposition Technology in Meandering Reservoir Prediction

分频技术原理是将一个短时窗内的地震数据通过离散傅里叶变换或最大熵谱估计转换为频率域,在频率域通过对地震反射成分中各种频率成分对应的调谐能量进行识别成像,并以此解释技术来识别地质体的空间展布形态、相对沉积厚度。研究区内明三段6砂组目的层段主要为曲流河沉积环境,储层厚度小,一般小于10m,横向变化大。由于该区明三段油层层速度在2200m/s左右,目前40Hz的地震主频可以分辨的砂体厚度为10m左右,因此通常储层预测方法对储层横向变化特征难以准确识别。运用该项技术在港东地区明化镇组曲流河储层中进行储层预测,取得了较好的效果。

Spectral decomposition principle was to transform the seismic data into the frequency domain via a Discrete Fourier Transform(DFT) or via a maximum entropy method transform(MEM).It was used to identify and image the syntony energy corresponding to the seismic reflection.Spectral decomposition could be used to identify the spatial distribution and shape of geologic bodies and corresponding sediment thickness.In the studied area,Ming 36 target zone was mainly in meandering sedimentary environment,reservoir thickness was generally less than 10m with high lateral reservoir changes.For velocity is about 2200m/s in Ming 3 Reservoir.At present 10 sand thickness can be identified at 40Hz seismic frequency,therefore conventional reservoir prediction method is difficult for identifying its lateral changes.The method is used for reservoir prediction in meandering reservoirs of Minghuazhen Formation and better effect is obtained.