Quantitative characterization method and quantitative characterization device for pore connectivity

Abstract

The invention provides a quantitative characterization method and a quantitative characterization device for pore connectivity. The quantitative characterization method comprises the following steps: performing three-dimensional digital imaging processing on a sample to obtain a two-dimensional digital image sequence of the sample; distinguishing two-dimensional digital images in the two-dimensional digital image sequence according to the sequence to generate a binary digital image sequence; generating a three-dimensional digital model according to the binary digital image sequence; determining the number of total pixel points and pore pixel points and location markers of all points in a three-dimensional digital model according to the preset resolution; determining pore connected domains of the sample according to a seed fill algorithm and the three-dimensional digital model; generating a pore connectivity quantitative characterization result according to the number of the total pixel points and the pore pixel points, the location markers of all the points and all determined pore connected domains. According to the quantitative characterization method, the pore connectivity of rocks can be characterized visually and quantitatively; the quantitative characterization method provides a powerful tool for physical property evaluation of reservoirs, the permeability evaluation of porous media and the like.

Description

technical field

[0001] The invention relates to the field of oil and gas physical exploration, in particular to a digital characterization method and device for rock pore structure. Background technique

[0002] Unconventional oil and gas systems are more complex than conventional oil and gas systems, and one of their important features is that unconventional oil and gas reservoirs (shale, tight sandstone, etc.) have small pore scales, low porosity, and very low permeability. The reservoir characteristics, occurrence mechanism and production process of oil and gas resources depend to some extent on the microscopic pore structure of oil and gas reservoirs. At present, the methods for characterizing the nanoscale three-dimensional pore structure of unconventional reservoirs are mainly nano-CT technology and focused ion / electron dual-beam scanning electron microscopy (FIB-SEM). Among them, the laboratory detection resolution limit of nano-CT technology is about 50nm; the resol...

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