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ID 25979
本文ファイル
著者
Tanikawa, Wataru
Shimamoto, Toshihiko
キーワード
Gas permeability
Water permeability
Klinkenberg effect
Sedimentary rock
NDC
地球科学・地学・地質学
抄録(英)
Quick measurements of permeability can be made by using gas as the pore fluid. To apply gas permeability data to the evaluation of water permeability, the difference between gas and water permeabilities needs to be assessed. We measured intrinsic permeability of sedimentary rocks from the western foothills of Taiwan by using nitrogen gas and distilled water as pore fluids in effective-pressure cycling tests at room temperature. The observed difference in gas and water permeabilities was analyzed in view of the Klinkenberg effect. This effect is due to the slip flow of gases at pore walls, which enhances gas flow when pore sizes are very small. Our experimental results showed that (1) gas permeability was larger than water permeability by several times to one order of magnitude, (2) gas permeability increased with increasing pore pressure, and (3) water permeability increased slightly as the pore-pressure gradient across the specimen increased. Results (1) and (2) can be explained quantitatively by an empirical power law in relation to the Klinkenberg constant b that is applicable in low permeable range. This correlation enables us to estimate water permeability from gas permeability. The Klinkenberg effect is important when permeability is lower than 10-18 m2 and at low pore-pressure differentials, and correction for the effect is essential to estimate water permeability from gas permeability measurement data. A simplified Bingham flow model for water can partially explain the trend of result (3), though non-Darcy flow behavior or inertial forces of water-rock interaction are needed to account for the observed deviation from Darcy's law.
掲載誌名
International Journal of Rock Mechanics and Mining Sciences
46巻
2号
開始ページ
229
終了ページ
238
出版年月日
2009-02
出版者
Elsevier Science Ltd.
ISSN
1365-1609
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
author
権利情報
Copyright (c) 2008 Elsevier Ltd
関連情報URL
部局名
理学研究科