Three-dimensional pore scale model reconstruction method based on rock micro CT image

Abstract

The application discloses a three-dimensional pore scale structured grid model reconstruction method based on a rock micro CT image. According to the method, by digital image denoising and binarization processing, partitioning and extraction of pores and skeletons in the rock micro CT image are completed, and storage of image data is implemented in a form of a three-dimensional array matrix; and on the basis of a corresponding relationship of model grid unit bodies and image pixels in the aspect of space positions, independently developed codes are utilized to complete search and space position calibration of the pixels of pore phases and skeleton phases, a structured network mode of the skeletons and the pores is constructed by adopting the grid unit bodies with the same sizes with the pixels, and a final model obtained by surface grid growth and geometric remodeling can be directly used for numerical calculation. The three-dimensional pore scale structured grid model reconstruction method disclosed by the invention improves the defects of poor grid quality, distorted topological structure and the like of a conventional reconstructed model, can meet numerical simulation requirements of problems of seepage, deformation, heat transfer and the like, and has the important significance for promoting researches in the related fields of energy mining and geotechnical engineering.

Description

technical field [0001] The invention relates to the technical field of rock physics, in particular to a reconstruction method for converting rock micro-CT images into three-dimensional pore or skeleton grid models that can be directly used for numerical simulation. Background technique [0002] At present, the computational model reconstruction methods based on rock microscopic digital images can be divided into two types: pore network model and grid model. The pore network model is based on the pore and throat characteristics of the image, and uses regular geometric structures to replace the pores and throats to achieve model reconstruction. For example, the pores are often represented by spheres and cubes, and the throats are often represented by cylinders, cuboids, and triangular prisms; This type of model simplifies the complex pore structure characteristics of real rocks, and can only be used for rock seepage performance analysis. The grid model is to convert the digit...

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Problems solved by technology

[0004] The purpose of the embodiment of this application is to provide a stable and efficient reconstruction method of three-dimensional pore-scale model based on rock micro-CT images, through the acquisition of original micro-CT images, digital image processing and segmentation and extraction of pore phase (skeleton phase) models, The initial structured grid model construction, surface grid growth, and model packaging operations complete the reconstruction of the structured grid model, solving the problems that the existing reconstruction methods cannot truly reproduce the microscopic pore structure characteristics of natural rocks and the poor quality of the model grid

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