Simulating generating and forecasting method for first arriving former noise for land exploration

Abstract

The invention relates to a simulating generating and forecasting method for a first arriving former noise for land exploration and belongs to a simulating generating and forecasting method for the first arriving former noise for seismic records. The chaos property reflected by the first arriving former noise is utilized to select a Duffing equation as a system, a generated signal has a time domain, a frequency domain and the chaos property which are more close to those of a practical first arriving former noise, and a random noise of the whole record is forecasted according to the system of the first arriving former noise, so that the purpose of suppressing the noise is achieved. The simulating generating and forecasting method has the advantages that the calculated quantity is small, the amplitude of a valid reflected wave in the seismic records is effectively kept, the valid reflected wave with high frequency in the seismic records is remained and the resolution is increased under the condition of achieving the purpose of suppressing the random noise. The existence of faults in the seismic data is further explained and a new strategy is supplied to the oil exploration, natural gas exploration and seismic data processing under complex environments.

Description

technical field [0001] The invention belongs to a method for simulating generation and prediction of noise before the first arrival of seismic records. Background technique [0002] In seismic exploration, the noise before the first arrival of the common shot record refers to the noise received by the geophone before the shot, which is a pure noise record, also called random noise, which can be detected by the geophone, but the noise after the shot The random noise cannot be distinguished from the record, which is superimposed on the effective reflection wave and various noises, which seriously affects the analysis of seismic data. In order to meet the three high requirements of high signal-to-noise ratio, high resolution and high fidelity of seismic records, It is necessary to suppress the random noise. Most of the existing methods for suppressing random noise are based on certain assumptions. For example, the noise before the first arrival is considered to be linear and s...

AI Technical Summary

Problems solved by technology

[0005] At present, there are many methods for suppressing random noise in seismic data, such as TFPF (Time-Frequency Peak Filtering), whose principle is to frequency-modulate the signal submerged in the noise into the instantaneous frequency of a constant-amplitude FM signal, and use WVD The peak value estimates the instantaneous frequency, restores the signal, and achieves the purpose of suppressing noise, but its disadvantage is that it cannot retain the effective reflected wave in the high-frequency signal, causing a certain loss to the effective reflected wave; the independent component analysis method is a signal-based Statistically independent of random noise and random noise to suppress noise; wavelet transform has strong frequency division and local analysis capabilities, and applying two-dimensional wavelet transform to two-dimensional signals can eliminate part of random interference, and there are many corresponding studies, such as Its extension methods such as Contourlet transformation

However, the current method of suppressing random noise in seismic records has not yet used its chaotic characteristics for noise suppression research.

Images