04 october 2004new and classical uses of heat flow studies, aachen1 geothermal resource mapping of...
Post on 21-Dec-2015
213 views
TRANSCRIPT
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 1
Geothermal Resource Mapping of Northern
Switzerland
Geothermal Resource Mapping of Northern
Switzerland
Thomas Kohl, Nathalie Andenmatten-Bertoud,S. Signorelli,L. Rybach
Geowatt AG, Zurich, Switzerland
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 2
BackgroundBackground
Project goal:– Interpretation of Swiss Resource
potential in main populated area
– 3D geological modeling
– Numerical analysis
– GIS interpretation
Conventional resource mapping:– Total Energy = f(T,V)
– Utilizable Energy = total Energy x recovery factor
Here:– 3D subsurface structures
– Evaluation of transmissivity
– Assumption of utilization scenario
– Utilization energy = f(Tr, T, ….)
– Combination with GIS toolsVTcE Ptot dtTQcE
fPut
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 3
3D determination of subsurface structures
3D determination of subsurface structures
Northern Switzerland
Well investigated for research of nuclear waste deposit– Borehole, seismic profiles, geophysical & geological interpretation
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 4
Geological 3D mappingGeological 3D mapping
• Geological surface interpolation with GOCAD software from data basis
• Example top Malm & Muschelkalk layers with borehole marker
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 5
Development of local numerical model
Development of local numerical model
– Triangulation of surfaces– Tetrahedrization of geological model– Construction of Finite Element Mesh
LeuggernBöttstein
BenkenWeiach
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 6
Numerical patch testNumerical patch test
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 7
Petrophysical DataPetrophysical Data
Measured and averaged parameters from Weiach
[W / m K]
Dep
th
0 1 2 3 4 5 6
0
500
1000
1500
2000
2500
Therm. Conductivity
Dep
th
0
500
1000
1500
2000
2500
Basement
Carbon
Perm
O. Muschelkalk
Perm
KeuperLiasDogger
Malm
U/M. Muschelkalk
Tertiary
Lithology
A[mW/m3]
Dep
th
10-1 100 101
0
500
1000
1500
2000
2500
Heat Production
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 8
Local temperature calculationLocal temperature calculation
• Calculation of thermal and hydraulic field:Example Weiach
-5000
-2500
0
670000672500
675000677500
680000682500
685000
260000
265000
270000
275000
XY
Z
TEMP: 9 10 11 12 25 50 75 100 125 150 175 200 225 250
Temperature [C]
Dep
th[m
]
0 50 100
0
500
1000
1500
2000
2500
Grad T [K/m]
Dep
th[m
]
0 0.02 0.04 0.06 0.08
0
500
1000
1500
2000
2500
WEIACH Data topWEIACH Data bottomModelled
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 9
Temperature DataTemperature Data
Weiach Benken
T red, 35K/km [K]
Dep
th[m
]
-5 0 5
0
500
1000
1500
BENKEN Data ABENKEN Data BModelled
Temperature [C]
Dep
th[m
]
0 20 40 60 80
0
500
1000
1500
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 10
Transmissivity evaluationTransmissivity evaluation
• Evaluation from existing data
• Thermal evaluation:– heat flow variation: background vs. local value – Peclet Analysis from regional borehole distribution:
relating heat flow variation to vD
– With assumption on head gradient =>Transmissivity estimation
zc
jj
zc
jj
fP
fP
2
1
D
D
2
1
ln
ln:AnalysisPeclet
v
v
Lc
j
jPe fP
D
kond
konvv
hKhK DD:Darcy vv
j2
j1
T
z
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 11
Utilization ScenarioUtilization Scenario
Doublet System:Calculation over time span t
Transient Gringarten (1978) solution:
– Necessary surface area– Sustainable flow rate– Reservoir geometry
=> Utilizable heat energy
= f(t, Tr, T, V, …)
in individual reservoir zoneDistance x
Transmissivity
21 /3ln
4
wi
bi rztcQ
PTrQ
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 12
Example: Resource PotentialExample: Resource Potential
Northern Switzerland:
Resource of altered crystalline basement for 30 yr production
Surface area <1km2
Borehole j [mW m-2 ]
Tr [m2/s] P[W] Recovery Factor
Weiach 25 5 x 10-6 3 x 107 5%
Böttstein 20 4 x 10-6 2 x 107 4%
Leuggern 20 4 x 10-6 2 x 107 4%
Benken 0 0 0 0%
Similar evaluation for sedimentary aquifers
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 13
Benken
Basserdorf
Lindau Local Model
Benken Local Model
Kloten
Nordschweiz Regional Model
Boettstein Local Model 100 – 110mW/m2.
WeiachBoettstein - Leuggern
110mW/m2.90mW/m2.
80mW/m2.
Beznau Birmenstorf
Riniken Local Model110mW/m2.
Weiach Local Model
Kaisten Local Model 110mW/m2.
Eglisau
Ruchfelden
Riniken
Zurzach
Kaisten
From Local to Regional ModelsFrom Local to Regional Models
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 14
Permocarbon Trog Rand
Temperatur:
Legend: N
Prel. Temperature Distribution in 2000m b.s.l
Prel. Temperature Distribution in 2000m b.s.l
04 October 2004 New and Classical Uses of Heat Flow Studies, Aachen 15
ConclusionConclusion
• Evaluation of 3D geology and regional temperature field
• Individual assessment of recovery factor and production time
• Cost analysis possible (borehole depth, geological structures, …)
• Future combination with GIS tools