Method for detecting caves based on similarity lateral change rate of frequency domain dip angles

Abstract

The invention provides a method for detecting caves based on a similarity lateral change rate of a frequency domain dip angles, and belongs to the field of petroleum geophysical exploration and development. The method comprises the following steps: 1, performing Hilbert transform on seismic data, transforming seismic data in a time domain to be in a complex domain to obtain Hilbert seismic traces, and calculating an instantaneous phase and a frequency domain dip angle of each Hilbert seismic trace; 2, performing similarity testing on the frequency domain dip angles obtained in the 1 step, and looking for abnormal points with poorer continuity, wherein relativity of all of the traces are calculated by adopting seismic wave field information, and uncorrelated abnormal boundaries are highlighted, so that fine terrane lateral non-uniformity and fracture features are identified, and respond features of cracks and the caves are amplified; 3, carrying out edge detection on similarity lateral change of the frequency domain dip angles to determine a development zone of a cave-type reservoir bed.

Description

technical field [0001] The invention belongs to the field of petroleum geophysical exploration and development, and specifically relates to a cave detection method based on the similarity lateral change rate of the frequency domain dip angle, which uses the frequency domain dip angle attribute results to carry out the edge detection scan of the similarity lateral change rate, which can be applied to Detection and identification of dissolved vugs in carbonate reservoirs in oilfield exploration. Background technique [0002] Similarity lateral rate of change is the similarity of seismic traces. At present, the more popular algorithms are based on cross-correlation and similarity-based algorithms. The main defect is that it only calculates the correlation relationship between adjacent traces and central traces, and cannot consider the correlation between adjacent traces. The relationship between each other in terms of structure; the second is that the combination of correlation...

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Problems solved by technology

[0002] Similarity lateral rate of change is the similarity of seismic traces. At present, the more popular algorithms are based on cross-correlation and similarity-based algorithms. The main defect is that it only calculates the correlation relationship between adjacent traces and central traces, and cannot consider the correlation between adjacent traces. The relationship between each other in terms of structure; the second is that the combination of correlation coefficients calculated in different directions has an average effect, and the more the number of calculation channels is, the more serious the average effect is, which reduces the spatial resolution and the continuity of abnormalities

[0004] The similarity lateral change rate is the similarity (coherence) of the seismic trace. At present, the technology development is relatively mature. The application in many work areas for many years shows that this method has a certain effect on detecting the abnormal points of the same axis on the seismic section. , but when the corresponding geological bodies are developed simultaneously with fractures and caves of different scales, this detection method can reflect the overall development of fractures and caves, but cannot distinguish the development characteristics of fractures and caves

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