Stratigraphic Structure Curvature Estimation Method Based on Combined Gradient Structure Tensor and Multi-Window Analysis

Abstract

The invention discloses a stratum structure curvature estimation method that combines a gradient structure tensor with multi-window analysis; the method comprises the following steps: 1, gathering three dimensional post-stack seismic data, and converting the data so as to obtain a complex seismic trace of each seismic signal; 2, calculating a three dimensional instantaneous phase data volume and an instantaneous phase gradient vector; 3, selecting adjacent analysis windows nearby each sample point; 4, calculating a visual dip angle and similarity in each adjacent analysis window; 5, selectingthe analysis window with the maximum similarity from all adjacent analysis windows, and appointing the corresponding visual dip angle as the visual dip angle of the analysis sample point; 6, determining whether the visual dip angles of all sample points are calculated or not; 7, calculating a partial derivative of the three dimensional visual dip angle data volume; 8, calculating the stratum structure curvature. The method can solve the stability and anti-fault interference problems in the three dimensional growl seismic data stratum structure curvature estimation, is easy to realize, and simple in operation.

Description

technical field [0001] The invention belongs to the field of exploration geophysics, in particular to a method for estimating the geometric curvature of a formation. Background technique [0002] Oil and natural gas are important strategic resources, which play a pivotal role in my country's national economy and national security. Seismic attribute is a measure of seismic exploration data, which can visually enhance features with interpretation significance, and directly reflect formation characteristics and reservoir properties. Therefore, seismic attributes can play an important role in the exploration and development of oil and gas reservoirs. Geometric attribute is one of the most important seismic attributes in seismic data interpretation. It is mainly used to enhance and display the geometric shape of seismic horizons, mainly including dip / azimuth, continuity, and formation curvature. The dip / azimuth attribute body contains important seismic stratigraphy and geograph...

AI Technical Summary

Problems solved by technology

[0008] Disadvantages: 1. Picking layers requires the assistance of software

[0009] 2. The formation curvature can only be calculated for the target horizon, not for this 3D seismic data volume

[0010] 3. It is greatly affected by human interference factors

[0015] Disadvantages: 1. Because only adjacent channels are used to calculate cross-correlation, it is greatly affected by noise

[0016] 2. The amplitude changes laterally and the error is large when crossing the fault

[0021] Disadvantages: 1. Due to the calculation of similarity or under each set apparent inclination angle, resulting in a large amount of calculation

[0022] 2. The accuracy of inclination estimation is limited by the sampling interval of apparent inclination

[0023] 3. The error is large when the analysis window crosses the fault

[0028] Disadvantages: Large lateral variation of amplitude and large curvature estimation errors when crossing faults

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