A static correction method for cannon first-arrival comprehensive modeling without surface survey data constraints

Abstract

A cannon first-arrival comprehensive modeling static correction method without a surface layer survey data constraint is a surface layer modeling and static correction processing method of seismic exploration data in geophysical exploration, uses filed earthquake collection material to generate a file, performs depth correction on well depth, obtains elevation of a shot point excitation surface, picks up first-arrival time of all shot point records within a certain arrangement range, then performs refraction layering on a public central point path set, and calculates refraction layer speed and delay time in a demodulation point receiving elevation position and a shot point excitation elevation position; and a database is used to perform chromatography inversion, a space speed model of a measuring line is obtained, a high speed interface corresponding to an analysis refraction layer is extracted from the model, the thickness of a surface layer above the high speed layer interface can be obtained, then the speed of refraction analysis, delay time and surface layer thickness are used to calculate the average surface layer speed of above the refraction layer, a datum plane and a speed parameter of static correction are defined, static correction of the datum plane is calculated, and a static correction amount of the invention is used for processing seismic data and eliminating influence of the surface layer on imaging of the seismic data.

Description

technical field [0001] The invention relates to a geophysical prospecting method, which is a method for surface modeling and static correction processing of seismic prospecting data. Background technique [0002] Static correction is a correction made to seismic data, which is used to compensate for the effects of elevation, weathered layer thickness and weathered layer velocity, and correct the data to a specified datum. Its purpose is usually to obtain the arrival time of reflected waves when collecting on a plane and there is no regolith or low-velocity medium. In seismic exploration areas, it is generally necessary to carry out surface surveys to obtain geophysical parameters related to the surface, directly use control point interpolation or use first-arrival information of cannons combined with surface survey information to invert to establish a surface model, and use the surface model to calculate the base level. Correction is a main data processing method in seismic...

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Problems solved by technology

[0005] In February 2006, "Petroleum Geophysical Exploration", Volume 41, Issue 1, disclosed a countermeasure for static correction of the piedmont alluvial fan surface: due to the large changes in the thickness and velocity of the piedmont surface alluvial fan, traditional surface survey and Static correction method calculation cannot completely solve the problem of "medium and long wavelength static correction amount"

However, in areas where no surface survey data have been carried out in the past or where it is difficult to carry out surface surveys, and areas where the surface survey data cannot survey the high-speed layer due to the extremely thick low-velocity zone, such as in some areas with complex surface structures, due to field surveys Difficulties and in many places it is impossible to carry out surface surveys normally or obtain surface information accurately, especially due to the huge thickness of the low-speed zone and the limitation of surface survey capabilities, the surface survey data cannot obtain the information of the entire near-surface, and the surface changes rapidly. The control ability of the surface survey points cannot accurately describe the changes of the surface model, and the surface model established relying on the surface information will have some insurmountable difficulties, and it is impossible to establish an accurate surface model. The accuracy of the model is low, which affects the effect of static correction

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