著者

大賀 光太郎 本位田 篤生

出版者

石油技術協会

雑誌

石油技術協会誌 (ISSN:03709868)

巻号頁・発行日

vol.73, no.6, pp.487-495, 2008 (Released:2011-02-22)

参考文献数

9

被引用文献数

2

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JCOP (Japan CO2 Sequestration in Coal Seams Project) has been commenced since JFY2002 with full subsidy from Ministry of Economy, Trade and Industry. Yuubari area of Ishikari coal field in Hokkaido was selected as the most suitable pilot test field, because the coal seams of this area are gassy and permeable.The preliminary field experiment was designed to investigate technical and economical feasibility of storing CO2 in coal seam until end of JFY2007.Injection well (IW-1) was drilled in the end of 2003, production well (PW-1) was drilled in the summer of 2004. The distance in the coal seam between the vertical injection well (IW-1) and the deviated production well (PW-1) was about 65m.CO2 injection and CH4 production tests were carried out from the end of this August to the end of October, 2007. From the measurement results, gas and water production rates were observed lower than estimated rates. The gas production rate increased gradually after carbon dioxide injection and then it reached the peak. After stopping injection, gas production rate decreased gradually to the initial gas production level. It is seems that this increase was due to the carbon dioxide injection.CO2 injection rate were also observed lower than estimated rate. History matching was carried out using the measured water production rate in 2005. From the results of history matching, these measured gas production rates were in agreement with calculation results. At that calculation, bottom of pressure of production well was 9MPa and permeability around the injection well was 0.13md. The high bottom hole pressure of production well shows that production damage is occurred. It is considered that perforation holes or cleat of coal plugged with fine coal particles might have caused this production damage. Two reasons for the decrease of permeability around injection well can be considered. One is that the gap of the coal cleats was reduced by the swelling of coal matrix due to CO2 adsorption. The other is that coal cleat was plugged by fine coal particles. From the measurement of gas content of coal in this test, it is conformed that gas content of coal seams in Ishikari coal field are in highest level. If the above mentioned problems on production damage is solved, CO2 injection into the coal seam and development of CBM will be commercialized soon.

著者

大賀 光太郎 板倉 賢一 出口 剛太

出版者

石油技術協会

雑誌

石油技術協会誌 (ISSN:03709868)

巻号頁・発行日

vol.77, no.6, pp.435-437, 2012 (Released:2014-03-29)

参考文献数

1

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In our laboratory, fundamental tests on underground coal gasification (UCG) by using coal blocks were conducted for several years. Last year, a small scale field test on UCG was carried out at a part of developing area of Mikasa surface mine in Hokkaido.At the field, two bore holes were drilled, one is incline bore hole and the other is vertical bore hole. The lengths of incline bore hole and vertical bore hole were about 5m and 1.4m, respectively. The vertical bore hole was used for an oxygen injection hole and ignition hole. The incline bore hole was used for a gas production hole. Some temperature sensors were installed around the incline bore hole to measure the temperature of around the production bore hole. AE sensors were also installed around the incline bore hole to estimate the gasification zone in the coal seam. Underground Coal Gasification (UCG) demands precise evaluation of the combustion area in the coal seam. Especially, the monitoring of fracture activity in the coal seam and around rock is important not only for efficient gas production but also for estimation of subsidence and gas leakage to the surface. The test was carried out for forty hours and production gases were analyzed at every thirty minutes.Experimental results obtained showed that the combustion propagated along the linking hole inside coal seam. The temperature gradients inside the coal and the composition of production gas were changed under constant oxygen flow rate. But Average thermal value of generated gases by field test was about as much as generated gases by laboratory test.

著者

崎元 尚土 島田 荘平 大賀 光太郎 熊谷 治夫 山田 理 海保 守 安田 肇

出版者

The Mining and Materials Processing Institute of Japan

雑誌

Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan (ISSN:18816118)

巻号頁・発行日

vol.126, no.10, pp.608-613, 2010-09-25

被引用文献数

1

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CO<SUB>2</SUB> sorption on coal was estimated by two experiments, one is heat of sorption measurement and the other is <SUP>1</SUP>H-NMR measurement. In the heat of sorption measurement, differential heat of sorption (<I>q<SUB>d</SUB></I>) was compared with the calculated one. Measured <I>q<SUB>d</SUB></I> was same value with calculated one at low pressure. It decreased gradually with pressure and became lower than the calculated one. Since it couldn't be explained by the theory based on physisorption, it is estimated that the coal-CO<SUB>2</SUB> system could not be explained by only simple physisorption.<BR>In <SUP>1</SUP>H-NMR measurement, spin-spin relaxation time (<I>T</I><SUB>2</SUB>) and composition fractions of L<SUB>1</SUB>, L<SUB>2</SUB> and G were measured. Composition fractions and <I>T</I><SUB>2</SUB> of L<SUB>1</SUB> increased with CO<SUB>2</SUB> gas pressure. Furthermore, the correlation was observed between volume increments and dissolution amount at over 10 atm. It indicates that part of CO<SUB>2</SUB> sorption capacity was used to coal relaxation.

著者

大賀 光太郎

出版者

石油技術協会

雑誌

石油技術協会誌 (ISSN:03709868)

巻号頁・発行日

vol.79, no.6, pp.419-423, 2014 (Released:2016-07-15)

参考文献数

10

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Coal reserve of Japan is about 20 billion tons. A half of them is in Kyushu and the other is in Hokkaido. The most gassy coal field in Japan is Ishikari coal field in Hokkaido. In Ishikari coal field there were so many underground coal mines, but now all of them were closed. The gas content of coal in the Ishikari coal field is more than 12 m3/t and CBM resources in Ishikari coal field is estimated about 40 billion m3.There are some reasons why CBM has never been developed in the coal field. One is that the Ishikari coal field is mountain area and most of it is covered with National Forest. Therefore, it is difficult to find the drilling site from the surface and to develop CBM on a large scale. The other one is that it is difficult to drill wells in a soft coal seam such as Yuubari coal and to maintain the wells. Therefore, we are planning to develop CBM to use for local energy in this area.

著者

Le Trung TUYEN 大賀 光太郎 井清 武弘

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.133, no.6, pp.140-150, 2017-06-01 (Released:2017-06-29)

参考文献数

17

被引用文献数

2

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2004 年5 月にホンタイ炭鉱で自然発火が発生して以降,ベトナムの四カ所の無煙炭炭鉱と一カ所の亜瀝青炭炭鉱で自然発火が続発している。これらに対処するため,筆者等は断熱環境下で石炭の酸化発熱試験ができる装置を使用して,各炭鉱の石炭試料について酸化発熱特性の試験を行っている。これらのデータについて実際に自然発火を発生している炭鉱の試料に注目してみると,150 ℃以下の低温領域の酸化反応速度が他の自然発火を発生していない炭鉱の石炭試料に比較して大きいことを見出した。即ち,低温域における石炭の酸化反応速度が自然発火の発生と深い関係があるという結論を得た。既存の自然発火性評価方法との比較も試みた。

著者

Le Trung TUYEN Nhu Viet TUAN 大賀 光太郎 井清 武弘

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.132, no.11, pp.167-174, 2016-11-01 (Released:2016-11-21)

参考文献数

13

被引用文献数

5

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無煙炭は自然発火し難いと一般的に言われてきたが,ベトナムの無煙炭炭鉱においては2004 年以降,幾つかの炭鉱において自然発火が多発するようになってきている。筆者等は,これら全ての自然発火事象の調査と対策に関わってきている。また,亜瀝青炭を採掘する一炭鉱における数回の自然発火事象についても調査を行った。本論文では無煙炭の自然発火の特性を中心に検討を行う。この中で,無煙炭の自然発火の指標ガスとして,瀝青炭などに見られる炭化水素系ガスは発生せず,一酸化炭素と水素の二種類のガスに限定されることを明らかにするとともに,自然発火防止の観点から現場の採掘条件の問題点などについても検討する。

著者

山口 伸次 大賀 光太郎

出版者

一般社団法人日本エネルギー学会

雑誌

日本エネルギー学会大会講演要旨集

巻号頁・発行日

no.12, pp.116-117, 2003-07-30