Seismic recognition method of low-order strike-slip faults in complex structural areas

Abstract

The invention belongs to the petroleum exploration field and relates to a seismic recognition method of low-order strike-slip faults in complex structural areas. The seismic recognition method of the low-order strike-slip faults in the complex structural areas includes the following steps that: post-stack seismic data quality is analyzed; processing is carried out to obtain an advantageous frequency division phase band; processing is carried out to obtain Sobel operators in main directions; processing is carried out to Sobel operators in arbitrary directions; a multi-direction lower-order strike-slip fault system is extracted; and the reliability of the low-order strike-slip faults is verified. The method of the invention is suitable for seismic recognition and verification reliability of lower-order strike slip faults in any complex structural belts and can directly reflect the combination modes and spatial locations of lower-order strike-slip faults on a plane; and the method is an effective measure to determine low-order hidden faults in low signal-to-noise ratio and low-frequency seismic data areas and can provide an important basis for re-understanding of hidden fault oil control rules, reservation and production improvement, development plan deployment and adjustment in complex structural oil and gas fields or fault block oil and gas fields.

Description

technical field [0001] The invention belongs to the field of petroleum exploration, and in particular relates to a seismic identification method for low-order strike-slip faults in complex structural areas. Background technique [0002] Strike-slip faults in oil and gas basins not only have diverse formation mechanisms and are widely distributed, but also play a very important role in oil and gas enrichment; low-order strike-slip faults, as a subtle regulatory fault pattern, often cause stress distribution in a local area. Inhomogeneity, resulting in a series of small fractures and micro-cracks, greatly improving the permeability of the reservoir, and greatly increasing the productivity of low-porosity reservoirs, but limited to the quality of seismic data in complex structural areas and low-order strike-slip faults often appear as one This regulatory structure type has the characteristics of concealment and multi-directional development, so its effective identification has ...

AI Technical Summary

Problems solved by technology

The tomographic image enhancement technologies mainly include adaptive directional filtering technology, boundary-preserving filtering technology and edge detection technology. The most commonly used edge enhancement technology uses differential operators that are sensitive to step changes in pixel gray levels to reflect discontinuity features and special rock features. Sexual body contours, such as Robert operator, Sobel operator, Prewitt operator, Laplacian operator, Canny operator, etc. Compared with other operators, Sobel operator has weighted the influence of pixel position, which can reduce edge blur degree, so the effect is better, and without considering the noise, the obtained edge information error does not exceed 7 degrees, but the extracted edge is relatively thick and needs to be refined, and the selection of the conventional threshold directly affects the detection result , and failed to carry out targeted treatment for faults in different directions

[0004] Therefore, under the premise of complex structural background, low-quality seismic data, unobvious strike-slip throw, and short fault extension distance, low-order strike-slip faults are highly concealed and difficult to identify, which requires the combination of advanced seismic processing technology and mathematical algorithms , to improve the Sobel operator to highlight the characterization results for faults in different directions, and no relevant reports have been seen so far

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