Pore structure representations based on nitrogen adsorption experiments and an FHH fractal model: Case study of the block Z shales in the Ordos Basin, China
| Autor: | Yanglei Zhou, Shengye Hao, Xinyu Qiu, Houfeng He, Pengcheng Liu, Liang Xu, Ce Shan |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Macropore Mineralogy 02 engineering and technology engineering.material 010502 geochemistry & geophysics Geotechnical Engineering and Engineering Geology 01 natural sciences Fractal dimension Fractal analysis Fuel Technology Fractal 020401 chemical engineering Shale oil Illite engineering Kaolinite 0204 chemical engineering Oil shale 0105 earth and related environmental sciences |
| Zdroj: | Journal of Petroleum Science and Engineering. 203:108661 |
| ISSN: | 0920-4105 |
| DOI: | 10.1016/j.petrol.2021.108661 |
| Popis: | Shale oil/gas is a crucial development in the exploitation of unconventional reservoirs. However, owing to the small pore size and complicated structure, finding an inexpensive and accurate method of accurately representing the pore structure has become an important issue. This paper summarizes and compares the current popular shale pore structure research methods and investigates three rock samples from well Z-1 and two rock samples from well Z-2 in block Z in the Ordos Basin, China. The components of the shale were analyzed using X-ray diffraction. In addition to the Brunauer–Emmett–Teller theory, there are also the Barrett, Joyner, and Halenda theoriesfor mesopores and the Horvath and Kawazoe method for macropore. Based on these theories, the pore size distribution was analyzed using nitrogen adsorption experiments at low temperatures. According to the fractal model of Frenkel–Halsey–Hill, the characteristics of the shale pore structure were studied. The fractal dimension values of single and bilinear segments fitted by double logarithm curves were applied to describe the fractal features of the pores, and the differences were compared. The relationship between the fractal characteristics and the pore parameters was analyzed. The outcomes of the tests indicate that the shale is mainly comprised of kaolinite, illite, and quartz, and the N2 adsorption curves are type IV. There are hysteresis loops, which indicate the occurrence of multi-layer adsorption. The fractal analysis revealed that the shales have significant fractal characteristics, which are chiefly affected by the mesopores and macropores. Otherwise, the fractal dimension values of the single line segment D and the bilinear segments D1 and D2 generally consistently represent the fractal pore features. Relationships were found between the pore parameters and the fractal dimensions. |
| Databáze: | OpenAIRE |
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