Automatic seismic gather leveling method and system

Abstract

The invention discloses an automatic seismic gather leveling method and system. The method may comprise the following steps of: step 1: carrying out distortion removal processing and energy balance processing on a seismic gather to obtain an initial gather; step 2: obtaining a reference track according to the initial gather, copying the reference track and obtaining a reference gather; step 3: calculating two-dimensional time shift amount of the reference gather and the initial gather, and performing time shift processing on the initial gather according to the two-dimensional time shift amountto obtain a deformed gather; step 4: judging whether the two-dimensional time shift amount is smaller than a time shift threshold value, if so, performing the step 5, otherwise, taking the deformed gather as the initial gather, and repeating the step 3-4; and step 5: adding the two-dimensional time shift amount obtained in each iteration to obtain a total time shift amount, and performing time shift processing on the seismic gather to obtain a leveling gather. The automatic seismic gather leveling method and system can automatically and quickly finish leveling of the seismic gather after conventional processing, and provides a high-quality seismic gather for seismic prestack inversion, reservoir prediction and fluid identification in the later period.

Description

technical field [0001] The present invention relates to the field of geophysical exploration, and more specifically, to an automatic leveling method and system for seismic gathers. Background technique [0002] The quality of pre-stack seismic gathers is directly related to the accuracy and reliability of seismic pre-stack lithology, physical properties, fluid inversion and AVO analysis results. , random noise interference, lateral anisotropy of the formation, and incomplete functions of the existing processing system, the quality of common reflection point (CRP) gathers generated by conventional prestack time migration processing is low, especially for uneven The ubiquitous phenomenon of fluctuation correction and stretching leads to poor results of pre-stack seismic inversion and AVO attribute analysis based on CRP gather data, which seriously affects the quality of subsequent seismic reservoir prediction and oil and gas detection results. [0003] At present, there are t...

AI Technical Summary

Problems solved by technology

The residual velocity analysis method (Necati Gulunay, 2007, Dave Hinkley, 2004) is based on velocity scanning to calculate the relevant velocity spectrum. The time resolution of the velocity spectrum is greatly affected by the characteristics of the gather itself and its quality. Strong formation reflection forms a velocity spectrum with strong energy. The weak formation reflection is weak on the velocity spectrum energy cluster, so the resolution is limited, and a lot of analysis and processing time is required by the processing personnel, which is time-consuming and inefficient

According to the similarity between adjacent channel data (QieZhang, 2016), the local cross-correlation algorithm can be used to realize automatic comparative analysis and calculate the time shift between adjacent channels, but the conventional local cross-correlation algorithm needs to set the calculation time window, And assuming that the time shift of each point in the calculation time window is constant, when the time shift is large or the time shift between two points before and after the change is relatively drastic, the method will fail

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