Vibrator Harmonic Suppression Method Based on Reconstructed Ground Force Signal

Abstract

The invention relates to a reconstructed ground force signal-based vibroseis harmonic wave suppression method. According to the method, when ground force signals cannot be estimated by a weighted summethod, on the basis of a characteristic that the arrival time of direct waves is inconsistent with the arrival time of other seismic waves, a proper matched filter is adopted to effectively separateand extract direct waves from signals near a substrate, so that the extracted direct waves can be adopted as reconstructed ground force signals and replace the actual transmitted signals of a vibroseis; and deconvolution processing is performed on seismic records, so that harmonic waves can be suppressed. The method does not replay on the control mode and specific coupling condition of the vibroseis, can suppress harmonic waves and greatly improve data quality. The method just has low requirements for the control method and control accuracy of the vibroseis, does not impose strict limitationson coupling between the vibroseis and the ground surface, and allows the vibroseis to adopt a low-cost open-loop control mode. The method has the advantages of wide application range, small target positioning error, is not only suitable for hydraulic vibroseis harmonic suppression, but also is suitable for open-loop control or harmonic wave suppression of various vibroseises with poor coupling conditions.

Description

Technical field: [0001] The invention relates to a seismic exploration method, in particular to a vibrator harmonic suppression method based on reconstructed ground force signals. Background technique: [0002] Vibroseis are favored in the field of exploration because of their advantages of safety, environmental protection, low consumption, high efficiency, and flexible methods. They account for a large proportion of applications in global land seismic exploration and acquisition, and there are a large number of foreign vibroseis There is a tendency to replace destructive sources such as dynamite sources. However, the existence of harmonic interference is one of the bottlenecks restricting the rapid development of vibroseis. The existence of harmonic interference damages the quality of vibroseis data and reduces the resolution of the data. Therefore, the suppression of harmonic interference becomes The research focus of vibrator technology and the technology of suppressing ...

AI Technical Summary

Problems solved by technology

Traditional harmonic suppression methods are mainly divided into two categories: one is to reduce the acquisition of harmonic interference components by improving the acquisition method and adjusting acquisition parameters. This method greatly simplifies the workload of later data processing, but this method The method cannot avoid the generation of harmonics, but can only make the harmonic interference in the collected data smaller and delay the occurrence of harmonic interference; another method is to perform phase shift filtering after correlating the collected original seismic records Or adaptive filtering and other processing methods to suppress harmonic interference, or perform deconvolution processing on the original seismic records to obtain formation reflection coefficients to suppress harmonic interference

The harmonic suppression effect of the second method is obvious, but this method is mainly suitable for conventional hydraulic vibrator, but not suitable for all kinds of vibrator with only open-loop control capability, because the weighted sum method cannot be used effectively at this time Estimate ground force signals, so such methods are of limited applicability

Cao (2010) used deconvolution instead of correlation to suppress the harmonic interference of conventional hydraulic vibrators with closed-loop control capabilities. This method can effectively suppress near-surface effects and harmonic components and improve data quality, but this method relies on Due to the precision control of vibrator and surface coupling conditions, it is feasible for the working environment of hydraulic vibrator with good coupling conditions in the exploration area, but it is feasible for hydraulic vibrator working in poor coupling conditions and other controllable vibrator with only open-loop control capability. Vibration source, harmonic interference suppression effect is very poor, and will produce phase shift, increase target positioning error

Images