Near-surface speed modeling method and device

Abstract

The invention provides a near-surface speed modeling method and device. The method comprises the following steps: acquiring working area micro-logging data and explaining an acquired result to obtain micro-logging lithological layering data and a speed explaining result; adopting a non-seismic exploration method to carry out surface layer structure investigation on a working area to obtain a surface layer structure explaining profile map; according to the surface layer structure explaining profile map, the micro-logging lithological layering data and the speed explaining result, determining a mathematic relation between the speed of each stratum or each lithological layer and a non-seismic physical geography property; determining a near-surface speed of each measured point in the non-seismic exploration method according to the mathematic relation between the speed of each stratum or each lithological layer and the non-seismic physical geography property; and carrying out interpolation by using the near-surface speed of each measured point in the non-seismic exploration method to obtain near-surface speed data of each seismic shot point and each wave detection point. By the aid of the near-surface speed modeling method and device, the near-surface speed model precision is improved, and the static correction effect of processing seismic data is easy to improve.

Description

technical field [0001] The invention relates to the technical field of seismic exploration, in particular to a near-surface velocity modeling method and a modeling device. Background technique [0002] In the process of seismic data processing, the static correction effect is one of the important factors directly related to the quality of the final processing results, and the static correction effect often depends on the accuracy of the near-surface velocity model, so as to obtain a fine near-surface velocity model that is closer to the real situation It is the basis for obtaining a good static correction effect. Especially when the near-surface structure is complex and the lithology varies greatly vertically and horizontally, it is particularly important to obtain a high-precision near-surface velocity model. [0003] At present, there are several commonly used methods for establishing near-surface velocity models. One is the model method. The commonly used data are mainly...

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Problems solved by technology

[0003] At present, there are several commonly used methods for establishing near-surface velocity models. One is the model method. The commonly used data are mainly micro-logging and small refraction data. The near-surface velocity information of each shot point and receiver point in the study area is obtained through interpolation. Due to the high cost and low production efficiency of micro-logging and small refraction methods, when the near-surface structure is complex, it is necessary to meet the requirements of establishing a fine velocity model. It requires a lot of micro-logging or small refraction work to ensure a certain density, but because of its production efficiency and actual input cost, it is often impossible to implement in actual production

Therefore, under the current limited investment situation, the application effect of this method in complex areas has been unsatisfactory; the second is the first arrival wave method, which uses the first arrival time in seismic data to obtain the near-surface velocity field through inversion. The effect is very good in areas with relatively simple near-surface structures, but when the near-surface structures are complex, the first arrival information in seismic data is seriously distorted and of poor quality. First arrival times at far offsets are more difficult to pick, if not impossible to pick

Therefore, some mature static correction techniques based on the first arrival cannot be applied in the static correction process of the complex surface structure area developed by igneous rocks

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