Correcting method for structure distortion phenomenon of seismic offset time profiles

Abstract

The invention provides a correcting method for a structure distortion phenomenon of seismic offset time profiles. The correcting method comprises the steps of building a construction model according to the geological information, establishing a layer speed model according to the speed information; building a construction + layer speed model, picking up a speed trap curve along a preset target layer; establishing a speed trap curve mode; analyzing the structure distortion phenomenon of the seismic offset time profiles; and using variable speed time depth conversion and /or pre-stack depth offset to correct the seismic offset time profiles with the structure distortion phenomenon. According to the method, the reasonability and accuracy of the structure morphology and the high point of seismic depth profiles can be effectively judged, the risk of drilling error can be reduced, and positive effects can be played in earthquake production and scientific research.

Description

technical field [0001] The invention belongs to the technical field of seismic data processing and interpretation of mountain complex structures in oil and gas field exploration, and more specifically relates to a method for correcting structural distortion phenomena in seismic migration time sections. Background technique [0002] Seismic exploration is an effective method to ascertain the shape of subsurface structures and discover structural reservoir traps. Through the acquisition and processing of seismic data, important seismic migration time sections are obtained. However, due to the large vertical and lateral changes in the velocity of complex structures and the influence of velocity traps, the structural shape on the seismic migration time section may be distorted, so that it cannot be truly reflect the structural form. The underlying stratum is affected by the structural shape and layer velocity structure of the overlying strata, which may cause velocity traps in ...

AI Technical Summary

Problems solved by technology

[0003] The traditional method for testing the accuracy of tectonic seismic results is the "well-seismic depth error test method", that is, through drilling, when the well-seismic depth error is less than the industry technical standard, the accuracy of tectonic seismic results is considered to be high, and the seismic migration depth profile reflects Structural form and stratigraphic depth are reasonable and accurate, otherwise the accuracy of tectonic and seismic results is low

If the structural distortion of the seismic migration time section is not corrected or overcorrected, there will be false structures and large errors in seismic prediction depth in the seismic migration depth section, which may lead to drilling errors, which may cause project scrapping and major economic losses

Because of the extremely high cost of drilling, the "well-seismic depth error test method" is difficult to become a routine method for production

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