Can we use wavelet phase change due to attenuation for hydrocarbon detection?
Han Li, Chuncheng Liu, Sanyi Yuan · 2015
Summary Seismic wave propagating in a fluid saturated medium generally produces attenuation and dispersion, which consequently change the frequency and phase of reflected wavelets. The frequency characteristics are usually used in reservoir prediction, while the phase characteristics are rarely used. There are two possible reasons for this, one of which is the unclear understanding of the phase behaviors of different kinds of reservoir, and the other of which is the lack of method to extract phase change information from seismic data. In this study, firstly, the causes of phase change due to attenuation are studied through numerical modeling. Then the complex spectral decomposition technique is developed to extract wavelet phase from seismic data. After that, the phase behaviors are further analyzed from seismic experiments on a physical model, in which the reservoir is filled with gas, oil or water. Finally, a real data example demonstrates the high time resolution of the proposed method in reservoir prediction and the successful application of the phase change in distinguishing gas saturated layers and water saturated layers.