地震波穿过地下含油气区时会表现为低频能量相对增强、高频能量相对减弱,准确提取地震波的低频能量和高频能量可以实现地下岩石的含油气性检测。利用短时傅里叶变换、S变换和引入尺度参数的匹配追踪算法对合成信号进行了试算,结果表明,引入尺度参数的Morlet小波匹配追踪算法不仅算法速度快,而且有更好的时频分辨率;通过对实际地震资料的匹配追踪计算,表明该算法也适用于实际资料;利用匹配追踪算法较准确地提取地震波的低频和高频能量,并对实际资料进行了含油气性预测,取得了与钻井一致的结果。
The seismic waves will comparatively enhance the low frequency energy and weaken the high frequency energy when propagating through the subsurface oil-gas-bearing media zone.Accurately extracting low frequency energy and high frequency energy of the seismic waves can realize the detection of the oil-gas-bearing nature of strata underground.In this paper,the synthetic signal was calculated by means of the short-time Fourier transform,S transform and introducing the matching trace algorithm with the scale parameters.The results show that the matching trace algorithm by introducing Morlet wavelet with the scale parameters not only holds a high speed but also has better time-frequency resolution.The application of field seismic data shows that the matching trace algorithm can achieve a good match of the field seismic data.The low frequency energy and high frequency energy of the seismic waves were exactly extracted by means of the matching trace algorithm and the prediction of oil-gas-bearing nature was conducted by using field data,conforming to the actual drilling data.