Method and device for enhancing longitudinal wave seismic data quality

Abstract

The invention discloses a method and device for enhancing the quality of longitudinal wave seismic data. The method comprises steps of carrying out the even polynomial fitting of the longitudinal waveseismic amplitude of each longitudinal wave pre-stack seismic trace gather through rejection fitting, and determining the even polynomial of the fitting longitudinal wave seismic amplitude of each longitudinal wave pre-stack seismic trace gather; determining the longitudinal wave seismic amplitude of the near-geophone offset seismic trace according to the even-order polynomial of the fitting longitudinal wave seismic amplitude and the incident angle of the reflection point of the near-geophone offset seismic trace; and determining the longitudinal wave seismic amplitude after wave mixing according to the longitudinal wave seismic amplitude of the near geophone offset seismic trace, the longitudinal wave seismic amplitude of each longitudinal wave pre-stack seismic trace set and the wave mixing weight parameter. According to the method, the even-order polynomials related to the reflection characteristics of the longitudinal wave seismic signals are adopted for step-by-step fitting, thesignal-to-noise ratio of the obtained fitted longitudinal wave seismic amplitude is high, the longitudinal wave seismic amplitude of the near-geophone offset seismic trace is determined according tothe even-order polynomials obtained through fitting, and the quality of near-geophone offset seismic data is effectively improved.

Description

technical field [0001] The invention relates to the technical field of seismic data processing, in particular to a method and device for enhancing the quality of longitudinal wave seismic data. Background technique [0002] This section is intended to provide a background or context to embodiments of the invention that are recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section. [0003] Pre-stack inversion is to use the seismic data amplitude change information with offset, through the reflection coefficient approximate formula inversion to obtain a variety of elastic parameters related to lithology, oil and gas, used to predict reservoir lithology, reservoir physical properties and oil-gas. The accuracy of prestack inversion depends not only on the inversion algorithm, but also on the quality of the seismic data involved in the inversion. The quality of seismic data directly affects the accuracy and reliability of pre...

AI Technical Summary

Problems solved by technology

However, due to the complex conditions near the surface of P-wave seismic data, the signal-to-noise ratio of seismic data near offsets is low and the noise is serious, and the quality of seismic data between them and COSCO offsets is quite different.

If the quality of near-offset seismic data is not improved, it will directly participate in the inversion together with the P-wave seismic data of COSCO offset, which will seriously affect the reliability of pre-stack inversion

Although denoising methods such as Radon transform and polynomial fitting can be used to remove noise in P-wave seismic data near offsets, the improvement in the quality of seismic data near offsets is still limited

[0005] Therefore, in the existing P-wave seismic data, the quality of the near-offset seismic data is poor.

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