Microscopic Pore Structure and Heterogeneity Quantitative Characterization of Shale Reservoir-Take in Chongqing Southeast Longmaxi Shale Case

The pore structure in intact and inelastically deformed Indiana limestone have been studied using x-ray microtomography imaging. Guided by detailed microstructural observations and using Multi-level Otsu’s thresholding method, the 3D images acquired at voxel side length of 4 μm were segmented into three domains: solid grains, macropores and an intermediate zone dominated by microporosity. Local Porosity can be defined to infer the porosity of each voxel. The macropores were individually identified by morphological processing and their shape quantified by their sphericity and equivalent diameter. With this segmentation, we obtained statistics on macropores on intact and deformed Indiana limestone which shows that inelastic compaction was followed by a significant reduction in the number of macropores. And also our results revealed the great potentiality to produce a quantitative analysis on porous material with the aid of micro CT images.

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Quantitative Characterization of Micropore Structure of Shale Reservoir

Acta Geologica Sinica - English Edition ◽

10.1111/1755-6724.12302_27 ◽

2015 ◽

Vol 89 (s1) ◽

pp. 63-64

Author(s):

Wenhao LI ◽

Shuangfang LU ◽

Haitao XUE ◽

Pengfei ZHANG ◽

Ying HU ◽

...

Keyword(s):

Quantitative Characterization ◽

Micropore Structure ◽

Shale Reservoir

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Quantitative Characterization of Heterogeneity in Different Reservoir Spaces of Low-Permeability Sandstone Reservoirs and Its Influence on Physical Properties

Advances in Civil Engineering ◽

10.1155/2021/2399016 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Fengjuan Dong ◽

Na Liu ◽

Zhen Sun ◽

Xiaolong Wei ◽

Haonan Wang ◽

...

Keyword(s):

Fractal Dimension ◽

Pore Structure ◽

Fractal Theory ◽

Fractal Dimensions ◽

Low Permeability ◽

Quantitative Characterization ◽

Average Value ◽

Porosity And Permeability ◽

Sandstone Reservoirs

The complex pore structure of low-permeability sandstone reservoir makes it difficult to characterize the heterogeneity of pore throat. Taking the reservoir of Sanjianfang formation in QL oilfield as an example, the fractal dimension of different storage spaces is calculated by using fractal theory based on casting thin section, scanning electron microscope, and high-pressure mercury injection, and the correlation between porosity, permeability, and contribution of different storage space permeabilities is analyzed. The results show that the reservoir of Sanjianfang formation in QL oilfield mainly develops small pores, fine pores, and micropores, and the fractal dimension of micropore structure is between 2.6044 and 2.9982, with an average value of 2.8316. The more complex the pore structure is, the stronger the microheterogeneity is. The higher the fractal dimension, the more complex the pore structure and the smaller the porosity and permeability. The fractal dimensions of small pores, fine pores, and micropores increase successively with the decrease in pore radius, and the microstructure heterogeneity of large pores is weaker than that of small pores. It provides a theoretical basis for the exploration and development of low-permeability sandstone reservoirs.

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Comparative analysis of shale reservoir characteristics in the Wufeng-Longmaxi (O3w-S1l) and Niutitang (Є1n) Formations: A case study of wells JY1 and TX1 in the southeastern Sichuan Basin and its neighboring areas, southwestern China

Interpretation ◽

10.1190/int-2018-0024.1 ◽

2018 ◽

Vol 6 (4) ◽

pp. SN31-SN45 ◽

Cited By ~ 10

Author(s):

Ruyue Wang ◽

Zongquan Hu ◽

Chuanxiang Sun ◽

Zhongbao Liu ◽

Chenchen Zhang ◽

...

Keyword(s):

Comparative Analysis ◽

Pore Structure ◽

Sichuan Basin ◽

Tectonic Deformation ◽

Hydrocarbon Generation ◽

Reservoir Characteristics ◽

Longmaxi Shale ◽

Methane Sorption ◽

Shale Reservoir ◽

Southeastern Sichuan Basin

A systematic comparative analysis of shale reservoir characteristics of the Wufeng-Longmaxi (O3 w-S1 l) and Niutitang (Є1 n) Formations in southeastern Sichuan Basin and its neighboring areas was conducted with respect to mineralogy, organic geochemistry, pore structure, methane sorption, brittleness, and fractures. Results indicate that (1) organic matter (OM)-hosted pores that are hundreds of nanometers to micrometers in size in the Longmaxi shale are well-developed in migrated OM rather than in the in situ OM, and they are the dominant reservoir spaces. Furthermore, the total organic carbon (TOC), brittleness, organic pores, and bedding fractures have good synergistic development relationships. However, there are fewer OM-hosted pores in the Niutitang shale; they are smaller in size, usually less than 30 nm, and have a more complicated pore structure. The intergranular pores in cataclastic organic-inorganic mineral fragments are the dominant reservoir spaces in the Niutitang shale and are coupled with stronger methane sorption and desorption capacities. (2) The piecewise correlation between TOC and brittleness indicates the significant differences in pore and fracture characteristics. When the TOC [Formula: see text], the TOC, brittleness, organic/inorganic pores, and fractures synergistically develop; when the TOC [Formula: see text], even though the increase in ductility reduces the number of fractures, the lower cohesive strength, internal friction angle, and weaker surfaces of interlayer fractures and cataclastic minerals promote the development of slip fractures, which significantly improves the fracture effectiveness and reservoir spaces for free and absorbed shale gas. (3) The Longmaxi, Wufeng, and Niutitang shales formed and evolved in different evolutionary stages. With the evolution of hydrocarbon generation, diagenesis, tectonic deformation, and pressure, the size and proportion of OM-hosted pores gradually decrease. At the same time, the complexity of the pore-fracture structure, the methane adsorption/desorption capacity, and the proportion of inorganic pores and fractures increase.

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