论文部分内容阅读
地震波在储集层中传播时,伴有能量的剧烈衰减,且频率越高能量衰减越快,因此,通过地震波高频端能量衰减梯度能够灵敏地检测地层中是否有烃类流体存在。短时傅里叶变换的时频分辨率不及Wigne-Ville分布,而Wigne-Ville分布虽有高的时频分辨率但存在交叉项的干扰。应用Wigne-Ville分布和短时傅里叶变换相结合的方法来计算地震信号的时频分布,然后利用高频成分能量分布与对应频率的拟线性关系估算出地震波能量衰减梯度。实际资料表明,基于短时傅立叶变换联合Wigner-Ville分布的能量衰减梯度在储集层预测中有较高的应用价值。
When seismic waves propagate in the reservoir, there is intense energy attenuation, and the higher the frequency, the faster the energy decays. Therefore, the presence of hydrocarbon fluid can be detected sensitively by the energy attenuation gradient at the high frequency of seismic waves. The time-frequency resolution of the short-time Fourier transform is less than the Wigne-Ville distribution, while the Wigne-Ville distribution has high time-frequency resolution but crosstalk. The Wigne-Ville distribution and the short-time Fourier transform are combined to calculate the time-frequency distribution of the seismic signal. Then the energy attenuation gradient of the seismic wave is estimated by the quasi-linear relationship between the energy distribution of the high frequency component and the corresponding frequency. The actual data show that the energy attenuation gradient based on short-time Fourier transform combined with Wigner-Ville distribution has high value in reservoir prediction.