Multiple-wave combined self-adaptive attenuation method

Abstract

The invention discloses a multiple-wave combined self-adaptive attenuation method and belongs to the field of multiple-wave attenuation of earthquake. The multiple-wave combined self-adaptive attenuation method comprises the following specific steps: firstly by taking an original record and a multiple-wave record obtained by a free-interface multiple-wave prediction method (SRMP) as initial records, extracting and pressing multiple-wave cophasal axes by using a cophasal axis optimizing and tracking technique and a short-time window FK visual velocity wave filtering method so as to obtain a quasi primary wave record and a quasi multiple wave record; then further eliminating residual multiple waves in the quasi primary wave record by using an extended Wiener wave filtering method and reducing original damaged primary wave information from the quasi multiple wave record. The method comprehensively takes the advantages of a multiple wave removing method based on cophasal axis optimization and tracking and of the extended Wiener wave filtering method, both commonly seen double-curve type multiple waves and other types of multiple waves can be effectively pressed, and the damage to primary waves can be reduced to a maximum limit.

Description

technical field [0001] The invention belongs to the field of seismic multiple wave suppression, and in particular relates to a combined adaptive attenuation method combining multiple wave elimination based on event optimization tracking technology and extended Wiener filtering. Background technique [0002] In recent years, multiple wave elimination methods based on wave equation theory, such as wave field extrapolation method, free interface multiple wave attenuation method (Surface–related Multiple Elimination, SRME) and inverse scattering series method, have made great progress. Among them, SRME method It has become the mainstream technical means of multiple wave suppression in current production. The multiple wave removal method based on wave theory usually includes two steps of multiple wave prediction and multiple wave attenuation, that is, wave theory first needs to predict the multiple wave components in seismic records, and then apply Various multiple wave adaptive...

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Problems solved by technology

[0006] Usually, multi-channel Wiener filtering methods can effectively suppress all kinds of multiple waves, but when the primary wave and multiple wave events intersect, it is very easy to damage the effective wave information; relatively speaking, the mathematical transformation domain The matching attenuation method has a better effect of eliminating multiples that cross the primary event, but it usually assumes that the multiple event conforms to the hyperbolic law, so it is not suitable for some non-hyperbolic areas in complex structural areas. In addition, when the apparent velocity difference between the primary wave and the multiple wave event is small (generally exists in near-offset traces), this type of method is also likely to cause damage to the primary wave.

It can be seen that the current commonly used methods cannot take into account both the extraction effect of effective waves and the suppression effect of multiple waves. Therefore, it is necessary to study a new method that can not only significantly improve the suppression effect of multiple waves, but also effectively avoid multiple waves. The damage to the primary wave signal during the process of secondary wave elimination, and it is suitable for multiple wave elimination in complex structural areas

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