Method for quantitatively characterizing fracture mechanical properties based on structural style analysis

Abstract

The invention discloses a method for quantitatively characterizing fracture mechanical properties based on structural style analysis. The method comprises the following steps: reading fracture-relatedstructural style characteristics based on three-dimensional seismic data, coherent data volume data and curvature data volume data; selecting five types of structural styles capable of reflecting fracture mechanical properties based on the difference characteristics of fractures under different property region stress backgrounds, and establishing a detailed structural style database; by establishing a membership function and an evaluation matrix, solving weight coefficients and membership degrees of the five types of structural styles, and preliminarily realizing conversion from geological features to quantitative data; establishing a quantitative evaluation mathematical model based on the five types of structural style weight coefficients and the single structural style membership degree, and solving a mechanical property numerical value of each breakpoint; and based on the mechanical property numerical value of each breakpoint, drawing a plane distribution diagram of the fracture mechanical property numerical value of each trunk by using Petrel software to finish division of the quantitative evaluation standard of the fracture mechanical property of the continental facies subsidence basin. According to the method, the fracture property can be efficiently, accurately and quantitatively described.

Description

Technical field[0001]The invention relates to a method for analyzing and quantitatively characterizing the mechanical properties of a fracture zone. In particular, it relates to a method for quantitatively characterizing fracture mechanical properties based on structural pattern analysis.Background technique[0002]The Cenozoic continental fault-bearing petroliferous basins in eastern China, whose development and evolution are generally controlled by the dual tectonic effects of horizontal extension generated by mantle upwelling and strike-slip shear generated by the activities of the Tanlu fault zone (Ma Xingyuan, 1983; Xu Jiawei, 1995) ; Qi Jiafu, 2014; etc.), leading to very developed faults in the basin and complex and diverse fault properties, which also leads to the complex and reservoir-controlling effects of faults, which have always been research hotspots and difficulties.[0003]In recent years, with the continuous deepening of exploration and development research in the Bohai...

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Problems solved by technology

However, the scale of in-situ stress generated by plate movement is relatively large, and there will be some differences in the release of stress on the target faults in the actual exploration practice. In-situ stress is nothing more than tensile stress, torsional (shear) or What is experienced in the process is not all a single in-situ stress, but more of a composite superposition of two or even three stresses, which also makes the judgment of fracture mechanics properties more complicated

[0005] Taking the Cenozoic faults in faulted basins in eastern China as an example, based on the dual dynamic background of strike-slip and shear, predecessors qualitatively divided the mechanical properties of fractures into tension, tension-torsion (or torsion tension), There are three types of strike-slip (Qi Jiafu, 2004; Yu Yixin, 2012; Wu Zhiping, 2013; etc.), but this classification scheme does not clearly define the basis and standard of classification, and it is easily subject to changes in human subjective cognition during the application process

The qualitative understanding of this "ambiguous" can no longer meet the increasingly refined needs of exploration and development. Therefore, it will be an important direction for future exploration and development to transform the qualitative geological understanding of fracture mechanics properties into quantitative numerical representation.

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