Submarine multiple prediction and tracking attenuation method in speed domain

Abstract

The invention relates to a submarine multiple prediction and tracking attenuation method in a speed domain, and belongs to the field of seismic data processing and analysis. The specific implementation process of the method mainly comprises the following four steps of: 1) creating a high-resolution speed domain record; 2) predicting a seabed multiple wave velocity spectrum based on an initial speed domain record; 3) tracking a hyperbolic multiple event; and 4) utilizing multiple wave event attenuation of FK fan-shaped filtering. Compared with a conventional multiple suppression method, the method does not depend on the period of multiple waves, and does not need to carry out dynamic correction processing on an input CMP gather; multiple wave suppression is carried out in a time-space domain, and the influence of a truncation effect is avoided; meanwhile, the length of the intercepted and recorded time window can be freely set, and when the time window is relatively small, multiple waves of which the superposition speed is relatively close to that of primary waves can be attenuated, so that the primary waves are prevented from being damaged; compared with a free interface multiple attenuation method, multiple in a far offset channel can be effectively suppressed, and the method has an obvious efficiency advantage.

Description

technical field [0001] The invention relates to the field of seismic data processing and analysis, and relates to a seabed multiple wave prediction and tracking attenuation method in velocity domain applied to seismic data. Background technique [0002] At present, the seismic exploration method used in oil and gas exploration is mainly the reflection wave method, which generally considers that primary reflection is effective, while direct waves, shallow refracted waves and multiple waves are interference waves. Interferences such as direct waves and shallow refracted waves can generally be cut off directly on the record, while the identification and suppression of multiple waves has been one of the hot issues that people have been focusing on for a long time. For marine seismic exploration, since the sea surface and the seabed are generally strong wave impedance interfaces, the corresponding seismic records usually contain a large number of seabed multiples with strong ampl...

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Problems solved by technology

Predictive deconvolution has the advantage of high efficiency, but the cycle of multiple waves is time-varying and space-varying, so it is impossible to give an accurate prediction step size, resulting in multiple wave residues or damage to effective signals, and it is difficult to effectively attenuate long period multiples

The multiple wave suppression method based on apparent velocity difference has been widely used in actual seismic data processing, but due to the small moveout in near-offset traces, it often leads to serious residuals of strong-amplitude multiple wave events, and the introduced dynamic Additional processing steps such as corrections, reaction corrections, etc. often produce waveform distortions in the processing results

Among the multiple wave suppression methods based on wave theory, the free interface multiple wave attenuation method (SRME) has become one of the preferred methods for seismic data processing, but it is difficult to effectively suppress multiple waves in far-offset traces, and the calculation The amount is large, which affects the application effect of SRME in actual production

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