Method for establishing near-surface velocity model in high-density seismic static correction processing

Abstract

The invention belongs to seismic data processing in petroleum geophysical exploration and geological engineering survey, and relates to near-surface velocity modeling and static correction in seismic exploration aiming at research and development of a shallow velocity model required for combined post static correction in a detector chamber of single-point high-density seism. A method for establishing a near-surface velocity model in high-density seismic static correction processing comprises the following steps of: supposing that the near-surface velocity is linearly increased along with the depth, calculating refracted wave velocity of different geophone offset from the travel time difference of primary waves of adjacent detection points of the high-density seism according to the physical property of the primary wave of the near-surface velocity field, establishing a near-surface ramp velocity field parameter according to the relationship between the geophone offset and the refracted wave, and further establishing the near-surface velocity model which can be directly used for static correction quantity calculation in seismic processing and also can be used as an initial model for tomographic inversion of near-surface velocity. The method has high calculation speed, and does not depend on the change of the initial position caused by a seismic focus.

Description

technical field [0001] The invention belongs to the seismic data processing in petroleum geophysical exploration and geological engineering investigation, and is aimed at the research and development of the shallow velocity model required in the indoor combined static correction of single-point high-density seismic geophones, and relates to the near-surface velocity in seismic exploration Modeling and static correction. Background technique [0002] In the post-static correction of single-point high-density seismic geophone indoor combination, although the indoor combination of single-point high-density seismic can eliminate the combined time difference caused by terrain changes and maintain the high-frequency components of the reflected signal, it still needs to be solved in subsequent processing static correction problem. Conventional processing techniques can be used for static correction processing after high-density seismic combination: including elevation static corre...

AI Technical Summary

Problems solved by technology

The near-surface survey obtains a reliable velocity structure of the observation point, but due to the high cost, generally only a limited number of points is measured, and the establishment of the near-surface model requires spatial interpolation; the velocity model of the first arrival inversion does not require spatial interpolation, but often The speed is difficult to obtain accurately

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