M-14(2001)

M-6 C^* 0.79 2.4 ( 4.7(b)) C^* 1.0

4.7(c) y 0.07 0.3

y M-12 y (0.15)

MR-1 (2000) M-12 M-13 (2002) M-6 C^* y

( 4.6 4.7)

C^* y

0 10 20 30 40 0.00

0.10 0.20 0.30 0.40 0.50 0 5 10 15

0 1 2 3 4 5 6 7

(a)

(b)

(c) 200°C

2-Propanol Ethanol

Ethanol / 2-Propanol

14 h

14 h Normalized tracer concentration, C iV /C iO (× 10-6 )Tracer concentration ratio, C*Steam fraction, y

Elapsed time, h

図4.8 M-11におけるトレーサー濃度，トレーサー濃度比および蒸気分率の時間変化

y 14 0.4 0.1

0.1 1.0 C^*

M-11 C^* y M-14

M-11

M-11 C^* y

4.6

3 (MR-1 M-13 M-14) ( 2.2)

(y)

y 4.9 y M-14 M-11

M-13 M-12 MR-1

M-1

2000 2007

(M-14 )

(Hanano and Matsuo, 1990)

MR-1 10

M-13 M-14 10

4.9

y y

Sumikawa River

Matsukawa River 0200 m

Aka

a w

Rive

feed point

wellhead bottom hole

M-15 M-2 M-9

M-8

MT-24 M-N3MT-22 M-13

M-5 M-12 y = 0.15 (max.) M-7 M-11 y = 0.4 (max.) y = 1.0 (assuming single- stage boiling)

M-14

MR-1

MT-23 M. N. M-10

Power Plant M-6 y = 0.3 (max.)

M-1 y = 0.02 (average) tracer flow path (direction)

図4.9 トレーサー試験結果から求めた蒸気分率の分布

M-6 0.3Well name steam fraction (y)

Higher temperature

Lower temperature

se Re

ir rvo mp te tu era tre re nd

M-11

y 0.4 y

0.1 ( 4.8) y

M-1 y M-11 y

の低下は注水による貯留層の冷

却を反映していると

1) M-11 M-14

2) 2001 M-11 M-14 50 70

3) M-11 (y) 14

4) (0.3% 2.3) M-11

M-11

4.8(b) C^* 14 1.0

M-11

C^* y 1.0 ( 4.4(a)) 14 C^*

1.0

M-14

M-11 y

M-11

y = 0.4 y = 1.0

y y C^*

C^* ( 4.8(b))

以上の議論から，

0.02 0.4 1.0 (y)

有効な方法といえる。

4.7

(y) ( )

( ) (C^*)

(B_i) (y)

1) (C^*) 1.0 3 M-12 M-6 M-11

2) 0.02 0.4

(y)

3) M-14 M-11 (C^*) 1.0

M-11

4) y y

Adams, M. C., Beall, J. J., Enedy, S. L., Hirtz, P. N., Kilbourn, P., Koenig, B. A., Kunzman, R., and Smith, J. L. B. (2001) Hydrofluorocarbons as geothermal vapor-phase tracers. Geothermics, 30, 747-775.

Adams, M. C., Yamada, Y., Yagi, M., Kasteler, C., Kilbourn, P., and Dahdah, N. (2004) Alcohols as two-phase tracers. Proceedings of 29th Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA, USA, January 26-28, 2004, SGP-TR-175, 8p.

Barker, B. J., Koenig, B. A., and Stark, M. A. (1995) Water injection management for resource maximization: Observations from 25 years at The Geysers, California. Proceedings of the 1995 World Geothermal Congress, Florence, Italy, May 18-31, 1959-1964.

Barr-David, F. and Dodge, B. F. (1959) Vapor-liquid equilibrium at high pressures: The systems ethanol-water and 2-propanol-water. Journal of Chemical and Engineering Data, 4, 107-121.

Bertrami, R., Calore, C., Cappetti, G., Celati, R., and D'Amore, F. (1985) A three-year recharge test by reinjection in the central area of Larderello field: Analysis of production data. Geothermal Resources Council Transactions, 9, 293-298.

Cappetti, G., Parisi, L., Ridolfi, A., and Stefani, G. (1995) Fifteen years of reinjection in the Larderello-Valle Secolo area: Analysis of the production data. Proceedings of the 1995 World Geothermal Congress, Florence, Italy, May 18-31, 1997-2000.

Chasteen, A. J. (1975) Geothermal steam condensate reinjection. Proceedings of the Second United Nations Symposium on the Development and Use of Geothermal Resources, San Francisco, California, USA, 20-29 May 1975, 1335-1336.

Doherty, M. F., Fidkowski, Z. T., Malone, M. F., and Taylor, R. (2008) Distillation. In Green, D. W.

and Perry, R. H. (Eds.), Perry's Chemical Engineers' Handbook, 8th ed., McGraw-Hill., 13–1-13–116.

Drummond Jr., S. E. (1981) Boiling and mixing of hydrothermal fluids: Chemical effects on mineral precipitation. PhD thesis, Pennsylvania State University, State College, PA, 381p.

Enedy, S., Enedy, K., and Maney, J. (1991) Reservoir response to injection in The Southeast Geysers. Proceedings of 16th Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, CA, USA, January 23-25, 1991, SGP-TR-134, 75-82.

Gambill, D. T. (1990) The recovery of injected water as steam at The Geysers. Geothermal

Resources Council Transactions, 14, 1655-1660.

Giovannoni, A., Allegrini, G., and Cappetti, G. (1981) First results of a reinjection experiment at Larderello. Proceedings of 7th Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, CA, USA, December 15-17, 1981, SGP-TR-55, 77-83.

Goyal, K. P. and Box Jr., W. T. (1992) Injection recovery based on production data in Unit 13 and Unit 16 areas of The Geysers field. Proceedings of 17th Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, CA, USA, January 29-31, 1992, SGP-TR-141, 103-109.

Goyal, K. P. (1999) Injection experience in The Geysers, California - a summary. Geothermal Resources Council Transactions, 23, 541-547.

Grant, M. A. and Bixley, P. F. (2011) Geothermal Reservoir Engineering. 2nd ed., Academic Press, 359p.

Griswold, J. and Wong, S. Y. (1952) Phase-equilibria of the acetone-methanol-water system from 100°C into the critical region. Chemical Engineering Progress Symposium Series, 48, 18-34.

Hanano, M. and Matsuo, G. (1990) Initial state of the Matsukawa geothermal reservoir:

Reconstruction of a reservoir pressure profile and its implications. Geothermics, 19, 541-560.

Henley, R. W. (1984) Gaseous components in geothermal processes. In Robertson, J. (Ed.), Fluid-Mineral Equilibria in Hydrothermal Systems, Reviews in Economic Geology Vol. 1, El Paso, TX, The Economic Geology Publishing Company, 45-54.

Poling, B. E., Prausnitz, J. M., and O'Connell, J. P. (2001) Fluid Phase Equilibria in

Multicomponent Systems. The properties of gases and liquids, 5th ed., McGraw Hill, 8.1-8.204.

Poling, B. E., Thomson, G. H., Friend, D. G., Rowley, R. L., and Wilding, W. V. (2008) Physical and Chemical Data. In Green, D. W. and Perry, R. H. (Eds.), Perry's Chemical Engineers' Handbook, 8th ed, McGraw-Hill, 2–1-2–517.

Stark, M. A., Box Jr., W. T., Beall, J. J., Goyal, K. P., and Pingol, A. S. (2005) The Santa Rosa-Geysers recharge project, Geysers geothermal field, California. Geothermal Resources Council Transactions, 29, 145-150.

Wilson, G. M. (1964) Vapor-liquid equilibrium. XI. A new expression for the excess free energy of mixing. Journal of the American Chemical Society, 86, 127-130.

5 5.1

( , 1980, p.31)

( , 1967; , 1967; , 1985)

( )

5.2

( , 1989) 1966 10 9.5

1967 12.5 MW 1968 20.0 MW 1973 22.0 MW

1993 23.5 MW ( , 2001)

5.2.1

5.1 26 km

( , 1988; , 1996)

(1988) (1983) (1967) Nakamura and Sumi (1967) Nakamura et al. (1970) (1981) (1968)

(1996) Ozeki et al. (2000) (2001)

5.2

13 1

( 5.2) (A A') 5.3

( ) 5.3

図5.1 松川地熱地域の位置

Sumikawa River

Matsukawa River

Sumikawa Fault

Dioritic intrusive r ock

0200 m

m 0

asl

0 20

asl m

m 0

asl

00 -2

asl m 00 -4

asl

500 m asl

-500 m

asl

0 m asl

Aka

a w

Rive

feed point

wellhead bottom hole

Legend

M-1

M-15 M-2 M-9

M-8

MT-24 M-N3MT-22 M-13

M-5

M-12 M-7 M-11 M-14

M-6

MR-1

MT-23 M. N.

Andesitic dikes

M-10

Power Plant

A A'

AA'Section line

図5.2 松川地熱地域の平面図

1000 500 0 -500 ASWA'NE

Ele vati on (m asl

)

500m0

Akagawa RiverMatsukawa G.P.S Matsukawa River M-15 M-2

M-1M-9

MR-1 M-8

M-5M-6 M-12

M-13 M-11M-7 M-14

(Quanternary)Matsukawa Andesite (Pliocene-Pleistocene)Tamagawa WeldedTuffs (upper) Tamagawa Welded Tuffs (lower) (Miocene)Takinoue-onsen Formation Kunimitoge Formation

Diorite

Andesitic dikes

(Holocene)Yuzaka Formation Sumikawa Fault

M-10 MT-24 (Miocene)

(Pliocene-Pleistocene) M-N3

図5.3 松川地熱地域の断面図

feed point

wellhead bottom hole

Dioritic intrusive rock

Yuzaka formation Matsukawa andesite Tamagawa welded tuffs Takinoue-onsen formation Kunimitoge formation Dioritic intrusive rock Andesitic dikes

( )

( ) ( ) ( ) ( 5.3)

( 300 m 700 m 1.1 km )

( )

( 5.2 5.3)

40 m 60 m ( , 1988)

( 5.2 5.3)

5.2.2

(Hanano and Matsuo, 1990)

3 6

(Hanano and Matsuo, 1990)

5.2.3

2001 11 2002 1

5.4 230 t/h

M-14 M-11 M-7 116 t/h

50%

(Hanano and Matsuo, 1990) M-13 M-6 M-5

M-8 M-12 59 t/h 26%

M-2 M-9 M-15 55 t/h

24%

5.2.4

Hanano

and Matsuo (1990) (1964 1965 )

( M-1) ( M-1 M-3)

M-1 M-2 M-3 257°C 258°C

250°C M-7

1970 277°C (Hanano and Matsuo, 1990)

M-7 M-7

M-7 (Hanano and Matsuo, 1990)

5.2.5

( , 1989) 1988 2005

0 200 m

feed point wellhead bottom hole

M-1

M-15

M-2

M-9 M-8

MT-24 MT-22 M-N3

M-13

M-5 M-12

M-7

M-11 M-14

M-6

MR-1 M. N.

図5.4 松川地熱地域の蒸気生産流量分布

9 8

21 (19)

15 (1) 12

23 20

15 (1) Steam ﬂow rate (t/h) (Water ﬂow rate) Representative ﬂow rates from November 2001 to January 2002

5.5

( ,

1989)

5.2.6

(CO₂)

(H₂S) (H₂) (N₂) (CH₄) (He) (Ar)

5.6 (1992)

1971 1987 (1966 )

5 1971 21

1987

M-2

D’Amore and Truesdell (1979)

5.7

Hanano and Sakagawa (1990) M-7 M-8

D’Amore and Truesdell (1979)

0 200 m feed point

wellhead

bottom hole M-1

M-15

M-2

M-9 M-8

MT-24 MT-22 M-N3

M-13

M-5 M-12

M-7

M-11 M-14

M-6

MR-1 M. N.

図5.5 松川地熱地域の最大密閉圧力分布

Results of build-up tests conducted in Octber 1988 showing maximum shut-in pressure in bar from Hanano et al., 1989)

Results of build-up tests conducted in June 2005 showing maximum shut-in pressure in bar based on internal data of Tohoku Hydropower & Geothermal Energy Co., Inc.)

M-2

図5.6 松川地熱地域の非凝縮性ガス濃度分布 (石崎・金藤, 1992)

Distribution of non-condensable gas in 1971Distribution of non-condensable gas in 1987

-291-

, k

HEAT LOST BY CONDUCTION

A A

6

MAIN HEAT SOURCE

E3 S t e a m Liquid water

Figure 4. Lateral steam movement and condensation in vapor-dominated geothermal systems.

3 0 0

100 50

’. ⁵

Figure 5. Results obtained frm the Raleigh condensation equation for K = 0.05 to 1000.

図5.7 DʼAmore and Truesdell (1979)による地熱蒸気の側方流動モデル

D’Amore and Truesdell (1979) M-2

(Hanano and Sakagawa, 1990)

5.3

5.8 5.9

( ) ( )

MR-1 MR-1 (2003) MR-1 (2000)

( 5.9)

5.8 5.9

4 ( )

1) (MR-1 M-5 M-12)

2) (M-6 M-13 M-13 M-6 M-7)

3) ( ) (MR-1 M-8 M-6 M-8)

4) (MR-1 M-1 M-15)

5.3.1

5.8 MR-1 M-5 M-12

M-14 M-7 M-11

Sumikawa River

Matsukawa River

Sumikawa Fault

Dioritic intrusive r ock

0200 m

m 0

asl

0 20

asl m

m 0

asl

00 -2

asl m 00 -4

asl

500 m asl

-500 m

asl

0 m asl

Aka

a w

Rive

feed point

wellhead bottom hole

M-1

M-15 M-2 M-9

M-8

MT-24 M-N3MT-22 M-13

M-5

M-12 M-7 M-11 M-14

M-6

MR-1

MT-23 M. N.

Andesitic dikes

M-10

Power Plant

A A'

AA'Section line

tracer flow path (direction)

図5.8 松川地域のトレーサー流動経路(平面図)

1000 500 0 -500 ASWA'NE

Ele vati on (m asl

)

500m0

Akagawa RiverMatsukawa G.P.S Matsukawa River M-15 M-2

M-1M-9

MR-1 M-8

M-5M-6 M-12

M-13 M-11M-7 M-14

(Quanternary)Matsukawa Andesite (Pliocene-Pleistocene)Tamagawa WeldedTuffs (upper) Tamagawa Welded Tuffs (lower) (Miocene)Takinoue-onsen Formation Kunimitoge Formation

Diorite

(Holocene)Yuzaka Formation Sumikawa Fault

M-10 MT-24 (Miocene)

(Pliocene-Pleistocene) M-N3

図5.9 松川地域のトレーサー流動経路(断面図)

feed point

wellhead bottom hole

tracer flow path (direction)

Andesitic dikes

Dioritic intrusive rock

2001 11 2002 1 ( 5.4)

M-5 M-6 M-12 M-7 M-11 M-14

66% (1985)

(1988)

( )

(1988)

(1984)

(1985) (1988)

M-11 M-14 ( 5.8)

5.3.2

5.8 M-6 M-13

M-13 M-7

M-6 M-7

( ) ( , 1988)

5.3.3 ( )

5.8 5.9 ( )M-6 M-8

MR-1 M-8

( )

M-6 M-6 M-8

(5.3.2 ) M-6 M-13

Heiken et al. (1988) Inyo Domes ( )

Obsidian Dome

(Eichelberger et al., 1985) 5.10

( )

Heiken et al. (1988)

5.11(Heiken et al., 1988)

5.12 (1988)

(Sumi, 1968)

( 280°C

; Hemley et al., 1980) (high sulfidation)

(SO₂) (Hedenquist, 1987)

Inyo Domes

﹂﹁ -コ OZ 00 0ト F﹂ Z凶 O︿

﹃︐ O︿

・凶

﹂﹁ Z一 ON 0Z 2N

↑E

︿コ 04

z︿

凶﹂ F4

︿一 00 凶区白

↑凶 Oコ Z﹀

ZO V凶 22

己一

U司_︼

u司

-o u_﹄

帽凶叫ロ - --唱

ω﹄

2M U惜 d_司しロ暗闇也

-u go uo晶

UU Hυ aS OS -2 0_的

岡吉

U国

OE Q

-師

﹀団

-咽

uz_一

冊師団﹄宮咽

u﹄

sr E -28 2Z EO NE og NZ 2σ

﹄幻自のけおお話

-h

討﹄刊誌切れ

hH LH UH uh

⁝山内一 bd h

日目討に

N HZ

訪

日

一一一一一一一

4337

EU晶

NN .F -ω ω凶 O﹂ Z凶 0広 0 Z凶 ω三ト凶白. 凶一 -三 00 ZO

﹂︿ Q凶 Z︿

﹂﹁ ω -o HEIKEN IT Aし:FRACTURE FIL凶AND ASH

Z凶

出店; : ぷ「

KL711

^ヨ

(w)HidヨG

O官 SN -s oo 孟﹀凶﹂凶

図5.10 Inyo Domesにおける火道および流紋岩岩脈周辺の水平フラクチャの分布(Heiken et al., 1988)

4348 He

・

"EN ET AL . :FRACTURE FILLS AND ASH

A

^. - - - r - - -f . . . . / 、

l 〆、、

! / / / ヘ

^\I/

〆ヘ. \

十- - \ ( I I

司、、̲

MAXIMUMPRINCIPAL STRESS

d-am410mp p-J 、\

ノノ乙ー『、\ ーー -z 一一一一一一ー

ト

^f/

^ノ /7/;γfJ\ 、、 \ \

^UP

ヤ開

t (-150 m fromdi同}

--I_I

ノ目、、、、

_' ^l

I I II

，，\ "

^---L

I / I .' II \'" 1 - -

- 一一一一

1 I II

、，、，

I / ，' ; IN

一一，

，

SHEETFRACTURE?

/ ト，

II w

，，、、

HYDROFRACTURE、

/ " I 11

- - - - 1 、˜ ˜

/ Ii" \ \ ^{I o}^w:rset

ノー II

//J11111Hoomfmmpike)

/lE111

.' ! Or I :

/! I I \

B

^10.0

a . .国

2 -; 8.0

コU ) 由也

C i ^7.0

δ包 ι6.0

D

} 1.00

. ，

^0.80

色咽

'. 0.40 c

/ ノ

9.0

GRANODIORITE ASSUMED

v= POISSONSRATIO~ 0.20

µ= SHEARMODULUS=0.22 x 10 Pa E= YOUNGSMODULUS=0.55

C

⁶⁰⁰

制抑

{ 制

￡白 co J_・

同

E

(

、師

)

司Q ) Q )a en

..!. 100

司、

∞

^CALCULATED^DIMENSIONS^FRACTURE

CALCULATED FLUID OVERPRESSURES

10em

∞

2em

5.0100 200 3

∞

⁴

∞

h・Depth (m)

500

O! : ，

2 4 6 8

w・Width (em)

CALCULATED FLUID VISCOSITY Steam，Wat町，&Pyroe也st

Mixture

10ロn .' 2cm

.' I

I_，

，

，' ²

∞

Time:< 2.8 -3.2 S

。。

² ⁴ ⁶ ⁸

w- Width (em)

，，

200 300 400

h- Depth (m)

500

Fig. 10. A model of volcanic hydraulic fracturing ・(α) Idealized sketch of the fracture geometry abo Y < :and adjacent to a vertical dike. Note that hypothetical contours (dashed lines) of maximum principal stress are vertically orie日ted near the

図5.11 岩脈貫入時の最大主応力分布と水平フラクチャ生成の関係 (Heiken et al., 1988)

― ―107

368

Fig. 7 Distribution of mineral zones at 200m below sea level in the Matsukawa geothermal field.

4.1.3 貯留層物理解析結果との関係

平子(1982)による松川貯留層の物理特性に関する研究結果によれば,地熱貯留層内の初期水飽和率の分布は,開発地の南東を中心に, NW‑SE性フラクチャーを軸としてその東側で狭く,その西側で広がる半楕円形を呈し,内側ほど水飽和率は小さい。このことも, NW‑SE性の澄川断層の存在を支持している。

4.2 推定フラクチャーの地熱貯留層としての意義

本研究から,当地熱地帯には3本の断層が推定され,蒸気はこれらの断層沿いに発達した貯留層から生産していると判断される。このように,地熱流体が断層に規制されて流動していると考えられている地熱地域として,八丁原やザ・ガイザースなどが挙げられる(真鍋・江島,1986:

Stockton et al.,1984)。

Yoshida(1984)は蒸気中のCO2・H2S・Rガスの組成比から,北東部に位置するMlb・MN3・

M9に比して,南西部に位置するM2・M5・M6・M7およびM8におけるH2Sの割合が高くCO2の割合が低いことを明らかにしている。Fig.8に,生産井M10とM11のデータを加えたこれら3成分の三角ダイヤグラムを示した。M10およびM11のガス組成比は南西部のグループに属する。推定断層と対応させれば,北東部のグループのMlb・M9は澄川断層に沿って流動し,南西部の

グループのM7・M8・M11およびT24は湯ノ森断層,同じく南西部のグループのM5・M6・M10

図5.12 松川地域のパイロフィライト分布(赤澤・村松 1988)

(3.2.5 )

( , 1989)

5.3.4

5.8 MR-1 M-1 M-15

5.4

(3.2.6 )

D’Amore and Truesdell (1979)

5.6

D’Amore and Truesdell (1979)

CO₂ H₂S H₂

Giggenbach (1980) Giggenbach

(1980) 5.13 (Wairakei, Kawerau, Broadlands)

H₂/H₂S ( Na–K )

Giggenbach (1980) (FeS₂) H₂ H₂S

FeS₂+H₂+

(

H₂O

)

^↔

(

^FeO

)

⁺^2H²^S ^(5.1)

2030 W. F. GIC~GENBACH

Values of S for Wairakei, Broadlands and Kawerau well discharges were calculated by use of eqn (20). Data points for discharges with values for y < /0.0#2/, indicating less

than 0.27: gain or loss of equilibrium vapor from the equi- librium liquid phase reaching the surface, follow a trend suggesting a decrease in the ratio H2/H2S with tempera- ture, contrary to the trends indicated by the pyrite-pyrrho- tite or pyrite-magnetite coexistence lines. Control of Hz and H2S concentrations by pyrite-pyrrhotite would require a rapid increase in S with decreasing temperature, while control by a pyrite-magnetite assemblage would cause S to remain largely constant. The observed trend, therefore, would suggest that relative hydrogen and hydro- gen sulfide concentrations are controlled by a third system involving ubiquitous pyrite and probably the iron contain- ing aluminium-silicate (Fig. 6).

The most likely type of mineral complementing pyrite in a hydrogen-hydrogen sulfide controlling geothermal reaction is an iron containing aluminium silicate similar to chlorite or epidote (BARTON et al.,

1977; GOGLIEL, 1976). No thermodynamic data for these minerals of highly variable and often uncertain compositions are available. The best approach appears to be to simply ascribe the observed trends in S with temperature to a reaction symbolised by eqn (40) and represented by the equilibrium expression of eqn (43). By assuming H,/H,S ratios for the low tem- perature system at Manikaran to be controlled t ‘Y

Fig. 6. Variations in the ratio H,/H,S as a function of temperature and CH,/CO,-ratios in the liquid phase for pyritepyrrhotite, pyrite-magnetite, pyrite-.-Fe-Al~sili~te

coexistence.

similar reactions, the data points can be fitted to eqn (17)from which, by use of eqn (46). empirical values for Kh may be obtained corresponding to

log I(, = -0.16 - 504.X,(r + 273.2). (56) Without defining the actual minerais involved in reaction 40, the data obtained allou a mineral phase stability diagram to be constructed ^asshown in Fig. 7 for 220’. 260” and 300°C. kll the data Faints. c&u- lated for discharges close to these ~emp~r~ltures and least affected by vapor gain or loss (Y < j O.o@i 1, for Broadlands and Kawerau wells occupy positions with hydrogen and hydrogen sulfide partial pressures of around 0. I bar. These partial pressures closely corre- spond to those of the pyrite-pyrrhotite magnetite tri- around 0.1 bar. These partial pressures closely corre- spond to those of the pyrite-pyrrhotire magnetite

triple point at temperature above 300 suggesting that Hz and H2S pressures are, at these high temperatures, indeed controlled by this iron oxide sulfide assem- blage. With decreasing temperature. however, the iron-aluminium-silicate stability tield expands rapidly leading to the complete disappearance of the magnetite stability field at temperatures below 240

It should be realised, that the nature of the mineral component symbolised by (FeO) may change with de- creasing temperature from that resembling chlorite to a mineral phase replacing chlorite at lower tempera- tures. These changes in the therm(~~iynanli~ cnviron- ment of (FeO), however, are likely to be gradual. and as outlined above, eqns (40) and (56) should be under- stood to describe a reaction including pyrite and two- valent iron in a possibly variable Al silicate enciron- ment and not in a specific mineral.

Another mineral system posstbly in ~quilibr~unl with geothermal gases may be symbohsed by the rcdction

CaCO, + H2S -t 3Hz0 r? CaSO, + COz -t 411~. (57)

calcite anhydrlte

Calcite-anhydrite coexistence lines for I’, (); of IO bar are shown in Fig. 7. They bypass analyt~~ai data points at considerably lower hydrogen partial pressures. especially at lower temperatures, suggesting that the presence of anhy- drite, frequently found in geothermal systems ( BROM.NE.

1978), is likely to reflect the more osidising conditions in a transition zone at the periphery of the geothermal system where the rising column of thermal fluids comes into con- tact with aerated, non-thermal grounduater

A simple check as to the att~~inment s>f calcrte ~~llhy~irite equilibrium within a geothermal system is obtamed by employing the pressure independent reaction

CaCO, + HzS + H,O(l) et C‘aSO, + CHA (58) whose equilibrium constant is adequately rcprexented by

log K,, = Iog(Sc,fHa;.%,,ti\ f = -4.74 - (~,~)(~8~. (59) Because of the small temperature term, lc,p 6 \h and, there- fore, log PCn41PHB are almost temperature Inllependent at around -4.9. By assuming the two gases as sampled to have been completely dissolved at equilibration according to X,j = X, i Ei, the theoretical \,a1 ues for x~.~~,/x,.)+~ =‘K,,&~i&,, drop to IO ‘. far from the value of close to unity observed for the ratio (.‘H,‘H,S for New Zealand and other thermal dlschargcs ( LYAMOKE and

図5.13 H

_₂

/H

_₂

S比の温度依存性 (Giggenbach, 1980)

(5.1) (FeO) (H₂O)

Giggenbach (1980) H₂/H₂S (5.1)

(FeS₂) (FeS) (Fe₃O₄)

FeS₂+H₂↔FeS+H₂S (5.2)

3FeS₂+2H₂+4H₂O↔Fe₃O₄+6H₂S (5.3)

5.13 H₂/H₂S

(Wairakei, Kawerau, Broadlands) H₂/H₂S (5.2) (5.3)

Giggenbach (1980)

H2/H2S CO2 Yoshida and Ishizaki (1988)

CO2

H₂/H₂S CO₂ 5.14

5.14(a) 1993 2005

5.14(a) 5.14(b)

( 5.2 5.3) 5.14(b)

( )

CO₂ H₂/H₂S

1993 2005

75 80 85 90 95 100 CO₂ (mol% in NCG)

0.0 0.1 0.2

H2/H2S

[3]

[2]

[6]

[5]

[4]

[1]

75 80 85 90 95 100

CO₂ (mol% in NCG) 0.0

0.1 0.2

H2/H2S

Central-deep Central-mid-depth Central-shallow East-deep SE-deep SW-deep

1993-2005

(a)

(b)

West East

Deep

Shallow

図5.14 松川地域生産蒸気のH

_₂

/H

_₂

SとCO

_₂

濃度の関係

M-7, M-11, M-14 M-6, M-8, M-13 MT-24 M-2, M-15 M-9 M-5, M-12

[1] Central-deep group: M-5, M-12, M-6 [2] Central-mid-depth group: M-6, M-8, M-13 [3] Central-shallow group: MT-24

[4] East-deep group: M-2, M-15 [5] Southeast-deep group: M-9

[6] Southwest-deep group: M-7, M-11, M-14 Grouping of production wells by steam chemical composition

H₂/H₂S Giggenbach (1980)

1) (Central–deep group) M-5 M-12 M-6

2) (Central–mid–depth group) M-6 M-8 M-13

3) (Central–shallow group) MT-24

4) (East–deep group) M-2 M-15

5) (Southeast–deep group) M-9

6) (Southwest–deep group) M-7 M-11 M-14 M-6

M-6 M-1 5.14

M-1

5.15 5.16

5.16

(M-14 M-11 M-7) (M-6 M-13 M-8)

M-14 (2001) M-6 (2000)

5.5

5.17 4

Sumikawa River

Matsukawa River

Sumikawa Fault

Dioritic intrusive r ock

0200 m

m 0

asl

0 20

asl m

m 0

asl

00 -2

asl m 00 -4

asl

500 m asl

-500 m

asl

0 m asl

Aka

a w

Rive

feed point

wellhead bottom hole

M-1

M-15 M-2 M-9

M-8

MT-24 M-N3MT-22 M-13

M-5

M-12 M-7 M-11 M-14

M-6

MR-1

MT-23 M. N.

Andesitic dikes

M-10

Power Plant AA'Section line

tracer flow path (direction)

A A'

East-deep group Southeast-deep group

Central-deep group Southwest-deep group

Central-shallow group Central-mid-depth group

図5.15 松川地域生産井の蒸気化学組成に基づくグループ区分(平面分布)

1000 500 0 -500 ASWA'NE

Ele vati on (m asl

)

500m0

Akagawa RiverMatsukawa G.P.S Matsukawa River M-15 M-2

M-1M-9

MR-1 M-8

M-5M-6 M-12

M-13 M-11M-7 M-14

(Quanternary)Matsukawa Andesite (Pliocene-Pleistocene)Tamagawa WeldedTuffs (upper) Tamagawa Welded Tuffs (lower) (Miocene)Takinoue-onsen Formation Kunimitoge Formation

Diorite Diorite

Andesite

(Holocene)Yuzaka Formation Sumikawa Fault

M-10 MT-24 (Miocene)

(Pliocene-Pleistocene) Diorite M-N3 East-deep group Southeast-deep groupCentral-deep group Southwest-deep group

Central-shallow group Central-mid-depth group

図5.16 松川地域生産井の蒸気化学組成に基づくグループ区分(断面分布)

feed point

wellhead bottom hole

tracer flow path (direction)

Sumikawa River

Matsukawa River

Sumikawa Fault

Dioritic intrusive r ock

0200 m

m 0

asl

0 20

asl m

m 0

asl

00 -2

asl m 00 -4

asl

500 m asl

-500 m

asl

0 m asl

Aka

a w

Rive

feed point

wellhead bottom hole

Legend

M-1

M-15 M-2 M-9

M-8

MT-24 M-N3MT-22 M-13

M-5

M-12 M-7 M-11 M-14

M-6

MR-1

MT-23 M. N.

Andesitic dikes

M-10

Power Plant tracer flow path (direction)

Periphery of the Sumikawa fault and the andesitic dikes Inside of the Takinoue- onsen formation (a country rock of the intrusive rock)

Inside of the dioritic intrusive rock Southeastern margin of the dioritic intrusive rock

図5.17 松川地熱地域の透水性フラクチャ分布

Geothermal steam supply in the west part

Geothermal steam supply in the east part

1) 2)

3) ( )

M-7 M-11 M-14

M-6 M-8

M-13 M-6 M-8

M-6 M-8 M-13

( 2.3)

(

M-8) 76%

M-1 M-2 M-15 M-9

MR-1 M-1 M-15

M-2 M-15

MR-1 M-1 M-15 M-2

5.6

1) (i) (ii)

(iii) ( ) (iv)

4 2)

(1988) . , 10, 359-371.

D'Amore, F. and Truesdell, A. H. (1979) Models for steam chemistry at Larderello and the Geysers.

Proceedings of 5th Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, CA, USA, December 12-14, 1979, SGP-TR-40, 283-297.

Eichelberger, J. C., Lysne, P. C., Miller, C. D., and Younker, L. W. (1985) Reserch drilling at Inyo Domes, California: 1984 results. Eos, Transactions American Geophysical Union, 66, 186-187.

Giggenbach, W. F. (1980) Geothermal gas equilibria. Geochimica et Cosmochimica Acta, 44, 2021-2032.

(1989) . , 26, 67-91.

Hanano, M. and Matsuo, G. (1990) Initial state of the Matsukawa geothermal reservoir:

reconstruction of a reservoir pressure profile and its implications. Geothermics, 19, 541-560.

Hanano, M. and Sakagawa, Y. (1990) Lateral steam flow revealed by a pressure build-up test at the Matsukawa vapor-dominated geothermal field, Japan. Geothermics, 19, 29-42.

(1967) . , 10, 35-51.

Hedenquist, J. W. (1987) Volcanic-related hydrothermal systems in the Circum-Pacific Basin and their potential for mineralisation. Mining Geology, 37, 347-364.

Heiken, G., Wohletz, K., and Eichelberger, J. (1988) Fracture fillings and intrusive pyroclasts, Inyo Domes, California. Journal of Geophysical Research, 93, 4335-4350.

Hemley, J. J., Montoya, J. W., Marinenko, J. W., and Luce, R. W. (1980) Equilibria in the system Al₂O₃-SiO₂-H₂O and some general implications for alteration/mineralization processes. Economic Geology, 75, 210-228.

(1985) . , 7, 201-213.

(1992) .

4 , B9.

(1983) . , 78,

479-490.

(1984) 2.

. , 354, 35-37.

(1996)

. 103 , 13-57.

(1980) . , 232p.

Nakamura, H. and Sumi, K. (1967) Geological study of the Matsukawa geothermal area, northeast Japan. Bulletin of the Geological Survey of Japan, 18, 132-146.

(1967) . , 10, 13-34.

Nakamura, H., Sumi, K., Katagiri, K., and Iwata, T. (1970) The geological environment of Matsukawa geothermal area, Japan. Geothermics, 2, Part 1, 221-231.

Ozeki, H., Fukuda, D., and Okumura, T. (2000) Recent studies and geothermal model of the Matsukawa area, Japan. Proceedings of Asia Geothermal Symposium, Bangkok, Thailand, 94-103.

(2001) . , 38, 27-56.

(1981)

. , 87, 267-275.

Sumi, K. (1968) Hydrothermal rock alteration of the Matsukawa geothermal area, northeast Japan.

Reports, Geological Survey of Japan, 225, 1-42.

(1968) .

, 17, 80-92.

Yoshida, Y. and Ishizaki, Y. (1988) Geochemical model of the Matsukawa geothermal field.

Proceedings of the International Symposium on Geothermal Energy, Kumamoto and Beppu, Japan, 128-131.

4 4 6

1) 2)

4 ( 1-

2-)

4) ( 40–80 )

トレーサ

。

4) 5)

(y) ( )

( ) (C^*)

(Bi) (y)

1) (C^*) 1.0 3 M-12 M-6 M-11

2) 0.02 0.4

(y)

3) M-14 M-11 (C^*) 1.0

M-11

4) y y

1) (i) (ii)

(iii) ( ) (iv)

4 2)

ドキュメント内九州大学学術情報リポジトリ (ページ 86-129)

図4.8 M-11におけるトレーサー濃度，トレーサー濃度比および蒸気分率の時間変化

図4.9 トレーサー試験結果から求めた蒸気分率の分布

の低下は注水による貯留層の冷

却を反映していると

以上の議論から，

有効な方法といえ る。

図5.1 松川地熱地域の位置

図5.2 松川地熱地域の平面図

Ele vati on (m asl

)

図5.3 松川地熱地域の断面図

図5.4 松川地熱地域の蒸気生産流量分布

図5.5 松川地熱地域の最大密閉圧力分布

図5.6 松川地熱地域の非凝縮性ガス濃度分布 (石崎・金藤, 1992)

6

図5.7 DʼAmore and Truesdell (1979)による地熱蒸気の側方流動モデル

図5.8 松川地域のトレーサー流動経路(平面図)

Ele vati on (m asl

)

図5.9 松川地域のトレーサー流動経路(断面図)

﹄ 幻 自 の け お お 話

討 ﹄ 刊 誌 切 れ

日 目 討 に

訪

日

一一一 一一一一

出店; : ぷ「

KL711

図5.10 Inyo Domesにおけ る火道および流紋岩岩脈周辺の水平フラクチャの分布(Heiken et al., 1988)

・

A

! / / / ヘ

〆ヘ. \

司、、̲

ノノ乙ー『、\ ーー -z 一一一一一一ー

ト

ノ /7/;γfJ\ 、、 \ \

ヤ開

ノ目、、、、

，，\ "

- 一一一一

、，、，

I / ，' ; IN

一一，

，

/ ト，

， ，、、

- - - - 1 、˜ ˜

.' ! Or I :

/! I I \

B

D

. ，

C

E

∞

∞

∞

∞

，

∞

。。

， ，

図5.11 岩脈貫入時の最大主応力分布と水平フラクチャ生成の関係 (Heiken et al., 1988)

図5.12 松川地域のパイロフィライト分布(赤澤・村松 1988)

(

)

(

)

図5.13 H

/H

S比の温度依存性 (Giggenbach, 1980)

(a)

(b)

図5.14 松川地域生産蒸気のH

/H

SとCO

濃度の関係

図5.15 松川地域生産井の蒸気化学組成に基づくグ ルー プ区分(平面分布)

有効な方法といえる。

﹄幻自のけおお話

討﹄刊誌切れ

日目討に

一一一一一一一

図5.10 Inyo Domesにおける火道および流紋岩岩脈周辺の水平フラクチャの分布(Heiken et al., 1988)

^ノ /7/;γfJ\ 、、 \ \

，，、、

，，

図5.15 松川地域生産井の蒸気化学組成に基づくグループ区分(平面分布)

図5.16 松川地域生産井の蒸気化学組成に基づくグループ区分(断面分布)