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Uehara, Shinichi*; Shimamoto, Toshihiko*; Kurikami, Hiroshi; Funaki, Hironori; Onishi, Yuzo*
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no abstracts in English
Uehara, Shinichi*; Shimamoto, Toshihiko*; Kurikami, Hiroshi; Niizato, Tadafumi; Funaki, Hironori; Onishi, Yuzo*
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no abstracts in English
Uehara, Shinichi*; Shimamoto, Toshihiko*; Kurikami, Hiroshi; Niizato, Tadafumi; Funaki, Hironori; Onishi, Yuzo*
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We performed permeability and porosity measurements by laboratory test under high pressure of Neogene and Quaternary sedimentary rock specimens from Horonobe area, northern Hokkaido island, Japan, and investigated the dependencies of these hydraulic properties on confining pressure and stress path. We then tried to evaluate permeability and porosity distribution as a function of the depth at this site from the measurement results and geological setting. The results indicated that the slope of permeability distribution is simulated reasonably well, which supports the applicability of this method of estimating underground hydraulic properties, but we can see some discrepancies in the value itself, which could be because of the effects of structures larger than specimen scale such as faults or fractures.
Okazaki, Keishi*; Uehara, Shinichi*; Shimamoto, Toshihiko*; Funaki, Hironori; Kurikami, Hiroshi; Niizato, Tadafumi; Onishi, Yuzo*
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We have conducted detailed permeability k and porosity n measurements using fresh surface samples and drill cores of the three Neogene sedimentary formations in Horonobe area. Main results are outlined as follows. (1) k and n decrease from upper to lower horizons due to compaction and cementation and with increasing effective pressure Pe. Pressure cycling tests provide basic data for estimating k and n structures of the host rock. (2) Measurements for two specimens cored next to each other under the same Pe exhibit relationship showing an increase in k with increasing n that can be fit with Kozeny-Carman relationship. (3) n plotted against logarithm of Pe shows a clear knee point, similar to compaction curves for soils. This knee point is several times as large as the maximum Pe estimated from stratigraphy and from opal A to CT transition, so that the knee cannot be correlated with the maximum burial depth of the sedimentary rocks.
Uehara, Shinichi*; Shimamoto, Toshihiko*; Funaki, Hironori; Kurikami, Hiroshi; Niizato, Tadafumi; Onishi, Yuzo*
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Estimation of deep underground permeability k structures is extremely difficult because transport properties of rocks are affected dramatically with fractures and fault zones and yet we do not know how much rocks are fractured and faulted at depths for a given region. We address this issue in the underground testing site in Horonobe area, where JAEA has been conducting a large-scale underground testing for sedimentary rocks. The Neogene sedimentary rocks of Horonobe area consist of Yuchi, Koetoi and Wakkanai Formations in the descending order. Hydraulic conductivity of Wakkanai Formation from in-situ measurements are compared with gas permeability as measured with a flow method for intact specimens, for fractured specimens and for breccia zones of Wakkanai Formation. In-situ data for hydraulic conductivity of lower part of Koetoi Formation is very close to that estimated from gas permeability of intact specimen, far smaller to those for brecciated samples.
Uehara, Shinichi*; Shimamoto, Toshihiko*; Funaki, Hironori; Niizato, Tadafumi; Kurikami, Hiroshi; Onishi, Yuzo*; Matsumoto, Takuma*
no journal, ,
Determination of underground transport properties is needed in modeling underground fluid flow, which is critically important in many problems such as fluid circulation, waste isolation, and carbon dioxide sequestration. Estimation of deep underground permeability structures is extremely difficult because transport properties of rocks are affected dramatically with fractures and fault zones and yet we do not know how to evaluate the effects of these structures on hydraulic properties distribution in depth. In-situ tests cannot provides transport properties at depths deeper than drill holes, whereas laboratory measurements can be done easily under conditions even deeper than 10 km as long as samples are available. Their applicability, however, to estimate real underground hydraulic structures is uncertain. Therefore, one should seek for a way of using laboratory and in-situ data complementary.
Okazaki, Keishi*; Shimamoto, Toshihiko*; Uehara, Shinichi*; Niizato, Tadafumi
no journal, ,
Permeability and porosity are essential physical properties for analyzing of underground fluid flow. We have examined the effect of deformation on permeability and porosity of the Neogene sedimentary rocks (Yuchi, Koetoi, and Wakkanai Formations in the descending order) by laboratory experiments. Wakkanai Formation can be fluid conduit due to deformation, whereas Yuchi and Koetoi Formations do not necessarily become fluid-flow passes even with deformation. The deepest part of Koetoi Formation seems to have the highest seal capacity among the three formations.
Uehara, Shinichi*; Matsumoto, Takuma*; Shimamoto, Toshihiko*; Okazaki, Keishi*; Niizato, Tadafumi
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no abstracts in English
Aoki, Kazuhiro; Seshimo, Kazuyoshi; Tanaka, Yoshihiro; Kametaka, Masao*; Sakai, Toru*; Okazaki, Kazuhiko*; Shimamoto, Toshihiko*
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no abstracts in English
Aoki, Kazuhiro; Seshimo, Kazuyoshi; Tanaka, Yoshihiro*; Niwa, Masakazu; Masuda, Yuki; Kametaka, Masao*; Sakai, Toru*; Shimamoto, Toshihiko*
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no abstracts in English
Seshimo, Kazuyoshi; Aoki, Kazuhiro; Kametaka, Masao*; Nussbaum, C.*; Shimamoto, Toshihiko*; Ma, S.*; Yao, L.*
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no abstracts in English
Aoki, Kazuhiro; Seshimo, Kazuyoshi; Guglielmi, Y.*; Nussbaum, C.*; Shimamoto, Toshihiko*; Ma, S.*; Yao, L.*; Kametaka, Masao*; Sakai, Toru*
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Seshimo, Kazuyoshi; Aoki, Kazuhiro; Tanaka, Yukumo; Niwa, Masakazu; Shimamoto, Toshihiko*; Ma, S.*; Yao, L.*; Kametaka, Masao*
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Aoki, Kazuhiro; Seshimo, Kazuyoshi; Nussbaum, C.*; Guglielmi, Y.*; Shimamoto, Toshihiko*; Sakai, Toru*; Kametaka, Masao*; Ma, S.*; Yao, L.*
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In order to contribute to the Fault Slip experiment, JAEA has performed friction experiment of borehole cores of the measured interval using a rotary-shear low to high-velocity friction apparatus at Institute of Geology, China Earthquake Administration. Friction experiments were done either dry with room humidity or with 30wt% of H
O, at a normal stress of 1.4 and 4.0 MPa and at low to intermediate slip rates ranging 0.21 microns/s to 2.1mm/s. Cylindrical specimens of Ti-Al-V alloy with 40 mm in diameter were used as rotary and stationary pistons and the alloy pistons exhibit similar behaviors as host rock specimens.