Method for reconstructing interval transit time curve by virtue of multiple logging curves

Abstract

The invention relates to a method for reconstructing an interval transit time curve by virtue of multiple logging curves. The method mainly comprises the steps of selecting a plurality of logging curves obvious in response to reservoir characteristics by performing reservoir sensitivity and correlation analysis on the logging curves; performing discrete wavelet decomposition on the logging curves together with a sonic wave curve to form 8 decomposition layers; enabling all the layers of high-frequency decomposition results of other logging curves except the sonic curve to form matrices respectively, obtaining the corresponding characteristic values and characteristic vectors of the matrices; taking the characteristic vectors corresponding to different characteristic values as new components, which, at the moment, have orthogonality (correlation ); performing multivariate regression analysis on the high-frequency components of the corresponding layer of wavelet decomposition of the sonic curve by utilizing characteristic vectors of each layer, calculating a weighting coefficient corresponding to each vector, returning a regression significance analysis result and determining the quality of regression; next, determining the number of layers of the sonic high-frequency components to be reconstructed by virtue of the characteristic vectors according to the regression significance analysis result, selecting multiple regression results as the high-frequency components for a part having more layers than selected layers, and remaining the high-frequency decomposition results of the sonic logging curves for a part having less layers than the selected layer, and then carrying out curve reconstruction by using the low-frequency components of the sonic logging curves and the high-frequency components obtained through regression so as to obtain a final sonic reconstructed curve.

Description

Technical field: [0001] The invention relates to a method for reconstructing the acoustic wave time difference curve by using various logging curves. Background technique: [0002] Acoustic curve reconstruction is a common method in wave impedance inversion. When the difference between the underground reservoir velocity and the mudstone velocity is small and the coincidence degree is high; the result of direct wave impedance inversion cannot accurately reflect the difference between the reservoir and the surrounding rock, resulting in a discrepancy between the wave impedance inversion result and the drilling result. Therefore, it is necessary to reconstruct the acoustic logging curves, add lithology information to the acoustic logging curves, and improve the recognition degree of the acoustic logging curves for lithology, so as to perform more accurate reservoir prediction. [0003] Multiple regression analysis is a regression analysis method to study the relationship betwe...

AI Technical Summary

Problems solved by technology

When the difference between the underground reservoir velocity and the mudstone velocity is small and the coincidence degree is high; the result of direct wave impedance inversion cannot accurately reflect the difference between the reservoir and surrounding rock, resulting in the inconsistency between the wave impedance inversion result and the drilling result

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