Fine velocity modeling method based on gas cloud region constraints

Abstract

The invention relates to a fine velocity modeling method based on gas cloud region constraints. The method comprises steps: a velocity model comprising a three-dimensional data mesh is defined, to-be-detected space is divided into a gas cloud region and a non-gas cloud region, and velocity data in the known logging data are used for counting velocity change trends of the gas cloud region and the non-gas cloud region; seismic interpretation horizon data are used and gas cloud region space distribution is combined to carry out block processing on the velocity model; velocity models for the gas cloud region and the non-gas cloud region are built; and a seismic interpretation horizon control technique is adopted to combine the velocity models for the gas cloud region and the non-gas cloud region, and an initial velocity model is acquired. In view of special geological phenomena in the gas cloud region, the gas cloud region and the non-gas cloud region are effectively distinguished, block modeling is carried out on the gas cloud region and the non-gas cloud region respectively, and through research on the velocity change trends of the gas cloud region and the non-gas cloud region, velocity modeling is carried out in a more targeted mode, the actual geological conditions are met, and the time-depth conversion precision is high.

Description

technical field [0001] The invention relates to the field of seismic data processing, more specifically, to a fine velocity modeling method based on gas cloud region constraints. Background technique [0002] In the field of seismic data interpretation, since the data obtained during seismic data acquisition is time-domain data, that is, the recording sequence of data is based on the information sequence received in chronological order starting from the beginning of recording, which cannot reflect the real underground (depth) position information. Therefore, it is necessary to perform time-depth conversion on such data before they can be used by geological experts as the basis for structural research or well deployment. The time-depth conversion depends on the velocity model. The quality of the velocity model determines the accuracy of the final time-depth conversion. The velocity model is the spatial velocity information established on the seismic grid, and each sampling p...

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Problems solved by technology

[0008] The conventional velocity modeling method is to use the velocity data of known wells to interpolate the velocity space under the control of the horizon, and then use the seismic data to process the velocity spectrum data to correct the velocity. The weakness of this method is that it is only applicable to the formation In the case of slow lateral velocity changes, such as areas with developed gas cloud areas, the spatial variation of velocity is relatively large, and conventional velocity modeling methods cannot reflect the relationship between the spatial variation of velocity in gas cloud areas and non-gas cloud areas

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