A method and system for predicting low-frequency information of broadband seismic wave impedance

Abstract

The invention discloses a method for predicting low-frequency information of broadband seismic wave impedance, comprising: using broadband post-stack seismic data and seismic wavelets to construct a complex frequency domain seismic wave impedance forward calculation operator; according to the complex frequency domain seismic wave impedance forward calculation operator, using Bayesian The initial objective function of seismic wave impedance is calculated by inversion theory; the initial model constraint is added to the initial objective function of seismic wave impedance to obtain the low-frequency information prediction objective function, and the low-frequency information of seismic wave impedance is obtained by solving the low-frequency information prediction objective function; this method only uses broadband seismic data, The low-frequency prediction of seismic wave impedance is realized, that is, without the restriction of logging information, reasonable low-frequency information prediction results can still be obtained under complex geological conditions such as lenses between wells or drastic changes in physical properties; the invention also discloses a low-frequency information prediction of broadband seismic wave impedance The system has the above beneficial effects.

Description

technical field [0001] The invention relates to the field of oil and gas seismic exploration, in particular to a method and system for predicting low-frequency information of broadband seismic wave impedance. Background technique [0002] Seismic wave impedance inversion is the main way to obtain the wave impedance of subsurface medium. The low-cut frequency range of conventional seismic data is generally 8-10 Hz, lacking low-frequency components. When seismic inversion is used to obtain subsurface medium wave impedance, it is generally necessary to use logging data to establish an initial low-frequency model of elastic parameters. The initial low-frequency model directly affects the rationality and reliability of pre-stack seismic inversion results. [0003] At present, the establishment method of the initial low-frequency model of elastic parameters is mainly based on seismic interpretation horizons or sedimentary facies as lateral constraints, and the elastic parameters ...

AI Technical Summary

Problems solved by technology

However, it is difficult to use this method to establish an effective model when there are complex geological conditions such as lenses or drastic changes in physical properties between wells, especially when the well information is relatively sparse during the exploration stage.

Therefore, how to overcome the shortcomings of conventional low-frequency information prediction methods that cannot be accurately predicted under complex geological conditions such as lenses between wells or drastic changes in physical properties is a technical problem to be solved by those skilled in the art

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