Longitudinal wave and transverse wave separation method and system

Abstract

The invention belongs to the technical field of seismic wave information processing, and particularly relates to a longitudinal wave and transverse wave separation method and system. The longitudinal wave and transverse wave separation method comprises the steps that step a: a total vector displacement wave field U is simulated by utilizing an elastic wave equation numerical value in an isotropic medium; step b: all the components of the vector displacement wave field U are inputted, and a longitudinal wave separation equation vp=-alpha(Nabla*U) and a transverse wave separation equation vs=-beta(NablaxU) are obtained through calculation, wherein vp refers to a longitudinal wave speed wave field of a time-space domain, vs refers to a transverse wave speed wave field of the time-space domain, and alpha and beta respectively refer to propagation speed of longitudinal wave and transverse wave; and step c: the longitudinal wave field and the transverse wave field are respectively calculated by utilizing the longitudinal wave separation equation vp=-alpha(Nabla*U) and the transverse wave separation equation vs=-beta(NablaxU). According to the longitudinal wave and transverse wave separation method and system, the separated longitudinal wave field and the transverse wave field have clear physical meaning with no requirement for correction of amplitude and phase again so that error and interference caused by positive and negative transformation of the numerical value can be avoided.

Description

technical field [0001] The invention belongs to the technical field of seismic wave information processing, and in particular relates to a method and system for separating longitudinal waves and transverse waves. Background technique [0002] Longitudinal waves and shear waves are two forms of seismic waves when they propagate underground. These two wave fields are usually coupled together to bring troubles to seismic data processing. For example, in elastic wave reverse time migration imaging, longitudinal and shear waves interfere with each other to form crosstalk noise, which affects the interpretation of migration profiles. A good processing method is to separate the longitudinal wave and shear wave of the seismic wave field before imaging, and then image the longitudinal wave and shear wave separately. In an isotropic medium, the polarization direction of the longitudinal wave is parallel to the propagation direction of the wave field, and the polarization direction of...

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Problems solved by technology

[0004] The present invention provides a method and system for separating longitudinal and shear waves, aiming at solving the problem of the separation of longitudinal and shear waves by directly using divergence and curl operators to separate longitudinal and shear waves. The meaning is not clear, and the amplitude or phase correction after separating the longitudinal and transverse waves leads to the technical problems of positive and negative transformation of the value, which brings errors and interference

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