Page 293 - Geothermal Energy Systems Exploration, Development, and Utilization

5.6 Bad Urach 269

Production borehole
(U4)
Injection borehole 400 m
Z =−3850 m (U3)

Profile line
60 m
Observation point
300 m

150 m

Z =−4150 m
800 m Z
Y X
300 m

Figure 5.14 Cuboid reservoir model with a borehole doublet (U3 and U4).

Z
Injection Production
X T = 323.15 K p =−10 MPa
s
s = r g z p =+10 MPa ∂p ∂T
zz
= 0 = 0
∂z ∂z
400 m
∂p ∂p
= 0 = 0
∂x ∂x 300 m
∂T ∂T
= 0 = 0
s
∂x s zz0 =r g z ∂x
s
l
s xx 0 = s = nr g z T =T r +w(z r −z ) p 0 = r g z
0
yy
∂p ∂T
∂z = 0 ∂z = 0
800 m
Figure 5.15 Thermodynamic system conditions for the geothermal reservoir.

cuboid are 300 m high, 300 m wide, and 800 m long (Figure 5.14). The observation
point is selected to be rather close to the injection borehole as the significance of
THM coupling during heat extraction is more evident in this area.
The reservoir depth is between 3850–4150 m. The corresponding THM system
conditions are depicted in Figure 5.15. Concerning the initial conditions (t = 0),