A Preprocessing Method for Seismic Horizon Tracking Based on Fractional Derivatives

Abstract

The invention provides a seismic horizon tracking preprocessing method based on a fractional derivative, which belongs to geophysical exploration field for petroleum and natural gas. The seismic horizon tracking preprocessing method comprises the following steps: (1) selecting a central pixel point of a seismic image, and then determining an order of a fractional differential; (2) selecting a filtering direction of an isotropy diffusion; (3) performing same-phase axis continuous enhancement on a central pixel point; (4) repeating the steps (1) to (3) on a next central pixel point until all pixel points are processed; (5) performing isotropy diffusion filtering processing; and (6) adjusting vertical resolution of the seismic image, and accordingly seismic horizon tracking preprocessing is finished. Through the method of the invention, transverse-direction continuity and vertical-direction resolution of a lineups can be controlled simultaneously. The preprocessing method for automatic tracking of seismic horizon has advantages of: simple process, high calculating efficiency and obvious effect.

Description

technical field [0001] The invention belongs to the field of petroleum and natural gas geophysical exploration, and in particular relates to a seismic horizon tracking preprocessing method based on fractional derivatives. Background technique [0002] Horizontal tracking plays a pivotal role in seismic data interpretation, and its accuracy plays an important role in subsequent seismic data processing and interpretation. Seismic horizon tracking can be simply divided into manual tracking, automatic tracking, and manual semi-automatic tracking. In recent years, commercial geophysical software and some geophysicists have developed seismic horizon tracking methods. The simplest method is to follow the peak of the seismic waveform Or trough tracking, other horizon tracking methods such as "Automatic Horizon Tracking Technology Based on High-Order Statistics" (Peng Wen, Xiong Xiaojun, etc., Xinjiang Petroleum Geology, December 2006), and even appeared in some commercial geophysica...

AI Technical Summary

Problems solved by technology

The purpose of all these automatic tracking methods is to reduce the heavy manual horizon tracking. When the seismic event is severely discontinuous, the results of automatic tracking horizons will be wrong. The current compromise is to use semi-automatic horizons with manual intervention. The tracking method skips the discontinuity points, but in actual production, if the continuity of the event axis is too poor, the semi-automatic tracking can only be done manually, which greatly consumes the energy of the interpreters. Therefore, to improve the accuracy of the automatic horizon tracking, it must Enhanced Event Continuity

[0003] In order to improve the accuracy of automatic horizon tracking, the continuity of the seismic event must be enhanced. The conventional method of enhancing the continuity of the event is to use a Gaussian smoothing filter, which is a low-pass filter that weakens the high-frequency components of the earthquake, allowing the The low-frequency component is relatively increased to enhance the continuity of the event axis. This method weakens the high-frequency component of the seismic signal and reduces the resolution of the seismic image in the vertical direction, which will reduce the accuracy of automatic horizon tracking and even cause the phenomenon of "cross-layer"

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