Continuum area surface layer high precision static correction method

Abstract

The invention relates to a geophysical exploration technology. The technology is high precision static correction method for a surface layer of a surface layer continuous medium area of seismic exploration data and comprises the steps: acquiring the elevation of a high-speed top interface and the thickness of a low-speed zone by a micrologging method; acquiring the near ground surface initial speed of each micro-logging point by performing conic fitting on the time-depth relationship of each mircologging in the area; performing interpolation according to the change of the plane position to acquire continuously-changing time-depth relationship in space of the whole area and a three-dimensional data volume; calculating the static correction of the low-speed zone and other static correction; and using a common method to perform seismic data processing on the static correction so as to acquire reflected wave imaging with high resolution. The technology can avert human delamination error at the near ground surface difficult to declaminate, and has wider applicability and commonality as well as higher precision compared with a sand dune curve.

Description

technical field [0001] The invention relates to a geophysical prospecting method, which is a surface high-precision static correction method of seismic prospecting data in a surface continuum area. Background technique [0002] In seismic exploration, static correction is mainly to solve the problem that the change of seismic wave travel time in the near-surface formation affects the reflection wave stacking imaging. Due to the existence of the low-velocity zone, the seismic reflection wave is close to the vertical direction when it emerges from the surface. The near-surface structure in the area with simple near-surface is layered, and the general algorithm of static correction is calculated according to the vertical travel time of seismic waves in the layered medium. It is difficult to layer the surface structure in areas where the near-surface changes continuously, and the conventional static correction algorithm is not applicable. The general method is to use statistica...

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Problems solved by technology

This method is suitable for desert areas or relatively small areas with relatively stable surface layers. No matter whether it is segmented fitting or segmented, there is no idea of ​​breaking through a single time-depth curve. It is not suitable for thick gravel areas with similar surface characteristics, wind-induced desert area

The surface layer of thick gravel area and eolian desert area conforms to the above-mentioned law in a single point or a small area, but the direct application of the above method to establish a time-depth curve (desert area is called dune curve, and gravel area can be called gravel curve) does not apply again, otherwise a large static correction error will be generated

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