A method of gas-bearing detection using seismic instantaneous centroid frequency

Abstract

The invention relates to the field of natural gas geophysical exploration, and is a method for extracting the instantaneous center-of-mass frequency of seismic waves by using seismic data, and then using the instantaneous center-of-mass frequency for reliably indicating the existence of natural gas, specifically: (1) Comprehensive utilization of geology, well logging and synthetic methods Accurately calibrate the target layer with seismic record data; (2) Use the CEEMD-based seismic instantaneous centroid frequency method to open a time window along the target layer to extract the seismic instantaneous centroid frequency attribute volume; (3) Use the seismic instantaneous centroid frequency attribute volume to determine the content of the target layer gas property; the present invention can effectively detect the gas content by analyzing the instantaneous center-of-mass frequency image of the seismic wave. The present invention has higher temporal and spatial resolution for the gas-containing detection results, and at the same time avoids the conventional spectral decomposition method based on short-time Fourier analysis and wavelet transform, which requires a large number of frequency division profiles to analyze and then use the best frequency division Hydrocarbon interpretation of the profile.

Description

technical field [0001] The invention relates to the field of natural gas geophysical exploration, and is a method of extracting the instantaneous centroid frequency of seismic waves by using seismic data, and then reliably indicating the existence of natural gas by using the instantaneous centroid frequency of seismic waves. Background technique [0002] In natural gas exploration, how to extract more useful information from the instantaneous attributes of seismic signals, especially the use of frequency anomaly information, combined with geological, logging and other data, to find meaningful natural gas reservoir belts is an important issue for petroleum geophysical researchers. The pursuit of the goal all the time is also a difficult problem. Fluid-bearing rock formations will cause energy loss of seismic waves during propagation, and the energy of seismic waves will attenuate significantly at high frequencies in the interior and lower parts of gas-bearing layers. Spectru...

AI Technical Summary

Problems solved by technology

Although the gas-containing detection technology based on the EMD time-frequency analysis method has better time-space resolution and accuracy than the gas-containing detection technology based on the traditional time-frequency analysis method, there are problems such as modal aliasing effect in the EMD method itself. , will cause the IMF decomposed by EMD to lack physical meaning and geological meaning, thus reducing the accuracy of gas-bearing detection

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