Non-surface consistency static correction method based on equivalent speed

Abstract

The invention discloses a non-surface consistency static correction method based on equivalent speed and belongs to the field of seismic exploration. The method comprises the following steps that: theequivalent speed of seismic waves transmitted from the ground to a static correction surface H is calculated according to a near-surface model; an offset distance mapping relation between an offset distance before static correction and an offset distance after static correction under the condition of the transmission of seismic waves along an actual propagation path is constructed according to the equivalent speed, and a travel time mapping relation between travel time before static correction and travel time after static correction under the condition of the transmission of the seismic wavesalong the actual propagation path is constructed according to the equivalent speed; and the offset distance and travel time of the seismic waves under the condition of the transmission of seismic waves along the actual propagation path are calculated according to the offset distance mapping relation and the travel time mapping relation. With the non-surface consistency static correction method based on the equivalent speed adopted, precision errors caused by the vertical transmission of seismic waves assumed by conventional static correction are avoided. Compared with the conventional staticcorrection, the method has higher precisions, can better keep an accurate space-time distance relation, and meanwhile can better guarantee subsequent imaging precision.

Description

technical field [0001] The invention relates to the field of seismic exploration, in particular to a non-surface consistent static correction method based on equivalent velocity that can be applied to seismic data processing in petroleum geophysical exploration. Background technique [0002] The static correction method is a commonly used method for complex surface seismic data processing, usually including refraction tomographic static correction, elevation static correction and first arrival tomographic static correction, etc. The difference is mainly in the near-surface velocity inversion The methods are different, and the static correction processing after the velocity is obtained is based on the vertical time shift based on the assumption of surface consistency. Existing static correction processing is one of the main difficulties in the processing of complex surface seismic data. Complex surfaces usually show dramatic changes in surface elevation and near-surface veloc...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is that the existing processing of seismic data is based on the static correction method based on the assumption of surface consistency. This method has large errors, which will affect the subsequent accurate imaging of seismic data processing.

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