Depth domain layer speed correcting method suitable for undulating surface

Abstract

The invention provides a depth domain layer speed correcting method suitable for an undulating surface, belonging to the field of the seismic data processing of the physical prospection in the petroleum geochemistry. The method comprises the following steps of: firstly, segmenting an offset distance, grouping input trace gathers according to the offset distances, carrying out the undulating surface prestack depth migration, and generating a common imaging point trace gather; carrying out undulating surface residual speed analysis, computing a high-order residual curvature spectrum, picking up a depth-residual curvature pair according to the local maximum value of the high-order residual curvature spectrum, and obtaining speed model correction quantity; carrying out spatial interpolation and smoothness on the speed model correction quantity, and adding the speed model correction quantity with an initial speed model to obtain an updated undulating surface depth domain layer speed model; and replacing the initial speed model with the updated undulating surface depth domain layer speed model, and carrying out the analysis of undulating surface prestack depth migration and the undulating surface residual speed once again, so that the precision of the speed model can be continuously improved.

Description

technical field [0001] The invention belongs to the field of seismic data processing of petroleum geophysical exploration, and in particular relates to a method for correcting depth domain velocity applicable to undulating surface, which is used in modeling and model correction and updating of depth domain velocity in seismic exploration. Background technique [0002] Prestack depth migration is one of the most important seismic data processing technologies at the present stage. It is an important method to solve complex geological structure imaging. It can directly provide seismic structural imaging data in the depth domain, and plays a pivotal role in the discovery of large-scale oil and gas fields. In prestack depth migration, the velocity of the depth domain layer is a crucial factor, and the accuracy of the velocity model directly determines the quality of the imaging results. The high-precision layer velocity comes from the residual velocity analysis of the initial lay...

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Problems solved by technology

[0004] Exploration problems under complex surface conditions have been the focus of research in recent years. Exploring the update technology of depth-domain layer velocity models under undulating surfaces is of great significance for improving the imaging accuracy of pre-stack depth migration under complex surface conditions. However, the existing The update method of the residual curvature velocity model based on the common imaging point gather is derived under the assumption that the surface is a horizontal plane, and does not involve the surface fluctuation factor

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