| Project/Area Number |
63460188
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
資源開発工学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
YUHARA Kozo Kyushu Univ., Fac.Engineering, Professor, 工学部, 教授 (30091333)
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| Co-Investigator(Kenkyū-buntansha) |
MOGI Toru Kyushu Univ., Fac.Engineering, Associate, 工学部, 助手 (80182161)
EHARA Sachio Kyushu Univ., Fac.Engineering, Assist.Prof., 工学部, 助教授 (10002346)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 1989: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | injection well / injection capacity / scale / jet-charger / jet perforator / ジェットチャ-ジ / 地熱坑井 / スケール / 還元容量 / 還元指数 / ジェットパーフォレーター / 坑井内発破 |
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| Research Abstract |
The geothermal power production needs production wells and injection wells.
The latter reinjects the thermal water separated from the produced geothermal fluid into the ground. It is effective to maintain pressure and temperature of the reservoir, and to avoid environmental bad influence by the surface disposal of the thermal water. Geothermal injection well used to decrease its capacity with time, then usually new injection wells must be drilled to maintain the total injection capacity of the system. It is one of the factors for rising cost of the geothermal power generation. Decreasing of injection capacity seems to be caused almost by scaling of silicic anhydrid or calcium carbonate on a strainer of the well or surface of cracks of the reservoir near well. If a new path can be opened near the closed crack, the injection capacity must be recovered. For improvement of the injection capacity of a injection well, a new method using jet perforator is developed. Jet perforator consists of thirty jet-chargers loaded on the wave type carrier, and put in a capsule.
Jet-chargers are linked together by a detonating cord which is connected to a detonator. Some experiments have been done for three geothermal wells at Otake-Hatcfobaru, Oita Prefecture and Sugawara, Kumamoto Prefecture. Jet- perforator exploded in an injection well can make small hole through casing pipe and surrounding rock. As the results, scale in and around injection well can be removed. Results of the experiments show that the injection index increase 1.2 to 4 times than the initial values.
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