基于地震剖面瞬时峰值能量频率的衰减分析与气藏预测方法

Seismic attenuation analysis and gas recognition using instantaneous peak energy frequency of seismic profile

由于流体本身的粘滞性和摩擦性,使得地震波在含油气地层中传播时衰减形成低频阴影.通过对叠后地震资料做时频分解,分析地层衰减特征,是当前除了AVO技术之外,比较流行的直接识别流体和气藏的技术.本文基于波动方程正演,模拟了地震波对含油气地层的响应.然后采用连续小波变换分析不同尺度剖面的瞬时能量特征,提取分频剖面上每一个点的峰值能量对应的频率,得到瞬时峰值能量频率剖面.通过分析瞬时峰值能量频率剖面,分析了地震波在地下介质中传播时的衰减特征.最后应用此方法对实际地震剖面进行了分析,验证了其有效性.

Due to the viscosity and friction of the fluid, the seismic wave propagateing in the media filled with oil and gas suffers attenuation, which may form a shadow area on the seismic profile. Beside the AVO techniques, using the time-frequency technology to analyze the attenuation information of the stack seismic profile is a popular technique for oil and gas recognition. In this paper, we simulate the seismic wave propagation through the underground media filled with oil and gas. Then we use the continuous complex wavelet transform to analyze the instantaneous energy distribution, get the frequency of the peak energy point by point on the seismic profile. By analyzing the acquired frequency profile, we can analyze the attenuation in the underground media. In the end, we use our method to analyze the practical seismic data, which proves that the instantaneous peak energy frequency is useful for oil and gas recognition.