3D characterization of porosity and minerals of low-permeability uranium-bearing sandstone based on multi-resolution image fusion

• 作者: Bing Sun Jing Zhang Shan-Shan Hou Sheng Zeng Shu-Wen Zhang Xin Bai
• 来源期刊: 核技术（英文版）
• 年，卷（期）: 2020,（10）
• 页码范围: 115-134
• 页数: 20页
• 语种: 英文

摘要

In the process of in situ leaching of uranium, the microstructure controls and influences the flow distribu-tion, percolation characteristics, and reaction mechanism of lixivium in the pores of reservoir rocks and directly affects the leaching of useful components. In this study, the pore throat, pore size distribution, and mineral composition of low-permeability uranium-bearing sandstone were quanti-tatively analyzed by high pressure mercury injection, nuclear magnetic resonance, X-ray diffraction, and wave-length-dispersive X-ray fluorescence. The distribution characteristics of pores and minerals in the samples were qualitatively analyzed using energy-dispersive scanning electron microscopy and multi-resolution CT images. Image registration with the landmarks algorithm provided by FEI Avizo was used to accurately match the CT images with different resolutions. The multi-scale and multi-min-eral digital core model of low-permeability uranium-bear-ing sandstone is reconstructed through pore segmentation and mineral segmentation of fusion core scanning images. The results show that the pore structure of low-perme-ability uranium-bearing sandstone is complex and has multi-scale and multi-crossing characteristics. The inter-granular pores determine the main seepage channel in the pore space, and the secondary pores have poor connectivity with other pores. Pyrite and coffinite are isolated from the connected pores and surrounded by a large number of clay minerals and ankerite cements, which increases the diffi-culty of uranium leaching. Clays and a large amount of ankerite cement are filled in the primary and secondary pores and pore throats of the low-permeability uranium-bearing sandstone, which significantly reduces the porosity of the movable fluid and results in low overall permeability of the cores. The multi-scale and multi-mineral digital core proposed in this study provides a basis for characterizing macroscopic and microscopic pore-throat structures and mineral distributions of low-permeability uranium-bearing sandstone and can better understand the seepage characteristics.

作者信息

序号	姓名	单位	发文数	被引次数	H指数	G指数
1	Bing Sun		1	0	0.0	0.0
2	Shan-Shan Hou		1	0	0.0	0.0
3	Sheng Zeng		1	0	0.0	0.0
4	Xin Bai		1	0	0.0	0.0
5	Shu-Wen Zhang		1	0	0.0	0.0
6	Jing Zhang		1	0	0.0	0.0