| 论文题目 | Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China |
| 论文题目（英文） | Fractal Analysis and Classification of Pore Structures of High-Rank Coal in Qinshui Basin, China |
| 作者 | Zhao, Difei;Guo, Yinghai;Wang, Geoff;Guan, Xin;周雪晴;Liu, Jing |
| 发表年度 | 2022-09-01 |
| 卷 | 15 |
| 期 | 18 |
| 页码 | 22 |
| 期刊名称 | ENERGIES |
| 摘要 | |
| 摘要_英文 |
The influence of high-rank coal's pore characteristics on the physical properties, gas-bearing properties, and exploitation of coal reservoirs is becoming more and more prominent. How to establish the classification to describe the pore networks combining quantitative and qualitative characteristics has emerged as a major problem, which may offer a scientific foundation to deepen the understanding of this issue. In this research, the structure and fractal characteristics of reservoir pores were determined after analyzing 20 high-rank coal samples from Xinjing Coal Mine in the Qinshui Basin with the application of the high-pressure mercury intrusion method (HPMI) and argon ion polishing-field emission scanning electron microscopy (AIP-FESEM). The results show that the tested coal samples were bipolar distributed, with transitional pores and micropores dominating the pore volume, followed by macropores. The Menger sponge fractal models manifested two or three distinct straight-line segments with demarcation points of 65 nm and 1000 nm. A natural classification with three major pore types of diffusion pores (D-pores), seepage pores (S-pores), and pico pores (P-pores), demarcated by pore size intervals of 65 nm and 1 nm and seven sub-types, was established to relate pores to pore networks based on these fractal characteristics and the kinetic characteristics of methane molecules. This classification scheme can characterize the relationship between pore types and the corresponding major occurrence and transport mechanisms of the gas. In addition, P-pores and D-pores are predominately nanoscale OM pores with three major genetic types of organic constituent interparticle pores (5-200 nm), metamorphic pores (<5 nm), and intermorphic pores (<5 nm). S-pores are more complex in origin and shape features, and the major types include outgas pores, plant tissue residual pores, mineral-related pores, and microfractures. The mean radius (Pa), total pore volume (Vt), apparent porosity (phi), and volume ratio of macro- and mesopores were positively correlated with the fractal dimension D1 of S-pores (>65 nm). Since fractal analysis is a more comprehensive characterization of reservoir structure and quantitatively reflects the pore structure, undulating state, and roughness of the inner surface, fractal parameters can be used as an important index to describe the pore structure characteristics of high-rank coal reservoirs.
|
Copyright © 中国科学院深海科学与工程研究所 备案证号：琼ICP备13001552号-1
琼公网安备 46020102000014号
地址: 三亚市鹿回头路28号 邮编：572000 网站维护：深海所办公室 邮箱：office@idsse.ac.cn
