Method for calculating high-precision reflection coefficient based on converted wave seismic data

Abstract

The invention provides a method for calculating a high-precision reflection coefficient based on converted wave seismic data. The method comprises acquiring converted wave seismic data, obtaining a converted wave migration section after preprocessing and a pre-stack migration are performed, establishing a multi-thin-layer objective function of a sparse constraint and a wave impedance constraint on the migration section, and calculating a high-precision reflection coefficient for the multi-thin-layer objective function by utilizing a frequency domain mapping and L1-norm joint optimization algorithm. The method can build relatively reasonable multi-thin-layer objective function based on the converted wave seismic data and obtain the high-precision reflection coefficient, solution accuracy and the anti-noise capability of the objective function are improved, and the obtained high-precision reflection coefficient can lay a solid foundation for subsequent high-resolution section reconstruction.

Description

technical field [0001] The invention belongs to the technical field of converted wave seismic data processing, and specifically relates to a method for obtaining high-precision reflection coefficients based on converted wave seismic data. Background technique [0002] At present, the fracture characterization of coherent volume is an important means to explore fractured reservoirs, and the acquisition of high-resolution data volumes and fracture parameters required for fracture prediction has always been a key research issue in the exploration of fractured reservoirs. Due to the characteristics of low signal-to-noise ratio and resolution of the wave, its resolution needs to be improved to facilitate the thin-layer resolution of subsequent interpretations. However, the conventional high-resolution processing method based on the assumption of minimum phase and white noise has a limited ability to improve the resolution of converted waves under the limitation of the main freque...

AI Technical Summary

Problems solved by technology

However, the conventional high-resolution processing method based on the assumption of minimum phase and white noise has a limited ability to improve the resolution of converted waves under the limitation of the main frequency band, and cannot meet the requirements of subsequent fracture prediction and resolution of the minimum thickness of multi-thin layers. It is necessary to adopt a new high-resolution processing idea, namely: a new idea of ​​calculating the high-precision reflection coefficient of the converted wave and high-resolution reconstruction of the high-frequency wavelet. The requirement of the minimum thickness of the layer can be obtained to obtain a high-quality profile with satisfactory crack prediction

[0003] Usually, the calculation of the reflection coefficient requires the construction of a multi-thin-layer objective function. However, due to the fact that the objective function constructed by the conventional method has many unreasonable features, there are differences in the extreme value, position and size of the reflection coefficient during the calculation process. errors, which lead to false images in subsequent high-resolution profiles

[0004] In addition, there are many methods to solve the objective function, such as simulated annealing method, conjugate gradient method, matching pursuit method, etc. Although these algorithms can obtain the reflection coefficient of the objective function, the accuracy and stability are poor, and they are not suitable for new constructions. The adaptability of the objective function is poor

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