Experimental study and finite element simulations for LN2 fracturing in coal from Karaganda Basin

IF 3.7 2区工程技术 Q3 ENGINEERING, ENVIRONMENTAL

Bulletin of Engineering Geology and the Environment Pub Date : 2025-02-28 DOI:10.1007/s10064-025-04114-4

Sotirios Nik. Longinos, Alisher Konysbekov, Piotr Skrzypacz

{"title":"Experimental study and finite element simulations for LN2 fracturing in coal from Karaganda Basin","authors":"Sotirios Nik. Longinos, Alisher Konysbekov, Piotr Skrzypacz","doi":"10.1007/s10064-025-04114-4","DOIUrl":null,"url":null,"abstract":"<div>This study looked at the effectiveness of liquid nitrogen (LN2) in two distinct coal fracturing processes, freezing time (FT) and freezing–thawing cycle (FTC), for specimens that were saturated with water. The effectiveness of cryogenic treatment for coal rocks was compared using uniaxial compressive strength (UCS) and Brazilian tests. The results indicated in both USC and Brazilian tests, FTC experiments showed better results compared to FT experiments, leading to the conclusion that it may be possible to attain a higher desired permeability improvement by using more LN2 injections in real-world LN2 fracturing applications. In brittleness analysis, FT experiments showed higher values than FTC in the B21, B22, B24, and B25 indexes, while FTC experiments showed higher values in the B19 and B20 indexes. A scanning electron microscope (SEM) was used for fracture evolution analysis. Further, numerical simulations detailed the stress distribution patterns within coal samples under cryogenic treatment, utilizing von Mises stress analysis to compare the progression over time. The simulation results, particularly at peak stress periods, strongly correlate with experimental data, validating the model's effectiveness. These findings offer substantial evidence for the feasibility of LN2-based treatments in enhancing coal bed permeability, with implications for improving the efficiency and safety of coal extraction processes.</div>","PeriodicalId":500,"journal":{"name":"Bulletin of Engineering Geology and the Environment","volume":"84 3","pages":""},"PeriodicalIF":3.7000,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of Engineering Geology and the Environment","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10064-025-04114-4","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}

引用次数: 0

Abstract

This study looked at the effectiveness of liquid nitrogen (LN₂) in two distinct coal fracturing processes, freezing time (FT) and freezing–thawing cycle (FTC), for specimens that were saturated with water. The effectiveness of cryogenic treatment for coal rocks was compared using uniaxial compressive strength (UCS) and Brazilian tests. The results indicated in both USC and Brazilian tests, FTC experiments showed better results compared to FT experiments, leading to the conclusion that it may be possible to attain a higher desired permeability improvement by using more LN₂ injections in real-world LN₂ fracturing applications. In brittleness analysis, FT experiments showed higher values than FTC in the B21, B22, B24, and B25 indexes, while FTC experiments showed higher values in the B19 and B20 indexes. A scanning electron microscope (SEM) was used for fracture evolution analysis. Further, numerical simulations detailed the stress distribution patterns within coal samples under cryogenic treatment, utilizing von Mises stress analysis to compare the progression over time. The simulation results, particularly at peak stress periods, strongly correlate with experimental data, validating the model's effectiveness. These findings offer substantial evidence for the feasibility of LN₂-based treatments in enhancing coal bed permeability, with implications for improving the efficiency and safety of coal extraction processes.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Bulletin of Engineering Geology and the Environment 工程技术-地球科学综合

CiteScore

7.10

自引率

11.90%

发文量

445

审稿时长

4.1 months

期刊介绍： Engineering geology is defined in the statutes of the IAEG as the science devoted to the investigation, study and solution of engineering and environmental problems which may arise as the result of the interaction between geology and the works or activities of man, as well as of the prediction of and development of measures for the prevention or remediation of geological hazards. Engineering geology embraces: • the applications/implications of the geomorphology, structural geology, and hydrogeological conditions of geological formations; • the characterisation of the mineralogical, physico-geomechanical, chemical and hydraulic properties of all earth materials involved in construction, resource recovery and environmental change; • the assessment of the mechanical and hydrological behaviour of soil and rock masses; • the prediction of changes to the above properties with time; • the determination of the parameters to be considered in the stability analysis of engineering works and earth masses.