scholarly journals Multiscale Research on Pore Structure Characteristics and Permeability Prediction of Sandstone

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
M. A. Shi-Jia ◽  
L. I. N. Yuan-Jian ◽  
L. I. U. Jiang-Feng ◽  
Kundwa Marie Judith ◽  
Ishimwe Hubert ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Target Material ◽  
Future Research ◽  
Distribution Method ◽  
Binary Images ◽  
Permeability Prediction

The random existence of many irregular pore structures in geotechnical materials has a decisive influence on its permeability and other macroscopic properties. The analysis and characterization of the micropore structure of the material and its permeability are of great significance for geotechnical engineering. In this study, digital images with different magnifications were used to examine the pore structure and permeability of sandstone samples. The image processing method is used to obtain binary images, and then, the pore size distribution method is used to calculate the pore size distribution. Therefore, based on the Hagen-Poiseuille formula, we get the prediction value of material’s permeability and compare it with the value obtained from mercury intrusion porosimetry (MIP). It is found that different microscopic images with different magnification and various statistical methods of pore size have a specific influence on the characterization of pore structure and permeability prediction. The porosity of different magnifications is not the same, and the results obtained at higher magnifications are more consistent with the results obtained with MIP. With the increase of magnification, we can observe more pores in large sizes. The effect of CPSD (continuous pore size distribution) in pore size statistics is better than that of DPSD (discrete pore size distribution). In permeability prediction, the prediction result of higher magnification images are closer to the instrument test value, and the value of DPSD is more significant than that of CPSD. In future research, an appropriate method should be selected to obtain a reasonable prediction of the permeability of the target material.

Numerical Algorithm for Pore Size Distribution Characterization of Materials from 3D Images

2013 ◽  
Vol 699 ◽  
pp. 584-589 ◽  
Author(s):  
Neven Ukrainczyk ◽  
Eduard Koenders ◽  
Klaas van Breugel
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Numerical Algorithm ◽  
Digital Image ◽  
Medial Axis ◽  
Characterization Of Materials ◽  
2D And 3D

This paper presents an image based numerical method proposed to obtain information regarding pore structure and organization of pores within materials based on 3D digital image input. The output of the numerical algorithm is a pore size distribution of materials. The algorithm is based on the combination of the two digital image processing algorithms: 1) a medial axis thinning algorithm to obtain 3D skeleton of the pore structure, and 2) the distance transform of an image. The method is tested on simple 2D and 3D microstructures of packed spheres, demonstrating the performance of the proposed method.

scholarly journals Fuzzy Random Characterization of Pore Structure in Frozen Sandstone: Applying Improved Niche Genetic Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yao Ya-feng ◽  
Lin Jian ◽  
Ge Jian ◽  
Peng Shi-long ◽  
Yin Jian-chao ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Conversion Coefficient ◽  
Nmr T2 Spectrum ◽  
Rock And Soil ◽  
Fuzzy Random

Nuclear magnetic resonance (NMR) technology provides an innovative method employed in detecting the porous structures in frozen rock and soil masses. On the basis of NMR relaxation theory, fuzzy random characteristics of the NMR T2 spectrum and pore structure are deeply analyzed in accordance with the complex and uncertain distribution characteristics of the underground rock and soil structure. By studying the fuzzy random characteristics of the NMR T2 spectrum, the fuzzy random conversion coefficient and conversion method of the T2 spectrum and pore size distribution are generated. Based on the niche principle, the traditional genetic algorithm is updated by the fuzzy random method, and the improved niche genetic algorithm is proposed. Then, the fuzzy random inversion of the conversion coefficient is undertaken by using the improved algorithm. It in turn makes the conversion curve of the T2 spectrum and pore size distribution align with the mercury injection test curve in diverse pore apertures. Compared with the previous least square fitting method, it provides a more accurate approach in characterizing complicated pore structures in frozen rock and soil masses. In addition, the improved niche genetic algorithm effectively overcomes the shortcomings of the traditional genetic algorithm, such as low effectiveness, slow convergence, and weak controllability, which provides an effective way for parameter inversion in the section of frozen geotechnical engineering. Finally, based on the T2 spectrum test of frozen sandstone, the fuzzy random characterization of frozen sandstone pore distribution is carried out by using this transformation method. The results illustrate that the conversion coefficient obtained through the improved algorithm indirectly considers the different surface relaxation rates of different pore sizes and effectively reduces the diffusion coupling effects, and the pore characteristics achieved are more applicable in engineering practices than previous methods.

scholarly journals Construction of pore structure and lithology of digital rock physics based on laboratory experiments

2021 ◽  
Vol 11 (5) ◽  
pp. 2113-2125
Author(s):  
Chenzhi Huang ◽  
Xingde Zhang ◽  
Shuang Liu ◽  
Nianyin Li ◽  
Jia Kang ◽  
...  
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Laboratory Experiments ◽  
Rock Physics ◽  
Reconstruction Method ◽  
Digital Rock Physics ◽  
Digital Rock ◽  
The Core

AbstractThe development and stimulation of oil and gas fields are inseparable from the experimental analysis of reservoir rocks. Large number of experiments, poor reservoir properties and thin reservoir thickness will lead to insufficient number of cores, which restricts the experimental evaluation effect of cores. Digital rock physics (DRP) can solve these problems well. This paper presents a rapid, simple, and practical method to establish the pore structure and lithology of DRP based on laboratory experiments. First, a core is scanned by computed tomography (CT) scanning technology, and filtering back-projection reconstruction method is used to test the core visualization. Subsequently, three-dimensional median filtering technology is used to eliminate noise signals after scanning, and the maximum interclass variance method is used to segment the rock skeleton and pore. Based on X-ray diffraction technology, the distribution of minerals in the rock core is studied by combining the processed CT scan data. The core pore size distribution is analyzed by the mercury intrusion method, and the core pore size distribution with spatial correlation is constructed by the kriging interpolation method. Based on the analysis of the core particle-size distribution by the screening method, the shape of the rock particle is assumed to be a more practical irregular polyhedron; considering this shape and the mineral distribution, the DRP pore structure and lithology are finally established. The DRP porosity calculated by MATLAB software is 32.4%, and the core porosity measured in a nuclear magnetic resonance experiment is 29.9%; thus, the accuracy of the model is validated. Further, the method of simulating the process of physical and chemical changes by using the digital core is proposed for further study.

scholarly journals Experimental investigation on pore size distribution and drying kinetics during lyophilization of sugar solutions

2018 ◽  
Author(s):  
Petra Foerst ◽  
M. Lechner ◽  
N. Vorhauer ◽  
H. Schuchmann ◽  
E. Tsotsas
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Freeze Drying ◽  
Three Dimensional ◽  
Drying Kinetics ◽  
Process Efficiency ◽  
Freeze Dried ◽  
Pore Size Distributions

The pore structure is a decisive factor for the process efficiency and product quality of freeze dried products. In this work the two-dimensional ice crystal structure was investigated for maltodextrin solutions with different concentrations by a freeze drying microscope. The resulting drying kinetics was investigated for different pore structures. Additionally the three-dimensional pore structure of the freeze dried samples was measured by µ-computed tomography and the pore size distribution was quantified by image analysis techniques. The two- and three-dimensional pore size distributions were compared and linked to the drying kinetics.Keywords: pore size distribution; freeze drying; maltodextrin solution; freeze drying microscope   

Characterization of Shale Pore Size Distribution by NMR Considering the Influence of Shale Skeleton Signals

2019 ◽  
Vol 33 (7) ◽  
pp. 6361-6372 ◽  
Author(s):  
Jinbu Li ◽  
Shuangfang Lu ◽  
Chunqing Jiang ◽  
Min Wang ◽  
Zhuoheng Chen ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution

Characterization of Silica-Based Monoliths with Bimodal Pore Size Distribution

2002 ◽  
Vol 74 (11) ◽  
pp. 2470-2477 ◽  
Author(s):  
Felix C. Leinweber ◽  
Dieter Lubda ◽  
Karin Cabrera ◽  
Ulrich Tallarek
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Bimodal Pore Size Distribution
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