Page 316 - Geothermal Energy Systems Exploration, Development, and Utilization

292 5 Geothermal Reservoir Simulation
injectivity of the reservoir is influenced primarily by the viscosity effect, but that
mineral reactions weaken this negative trend. Operation of a geothermal heating
plant at the Stralsund location would not be restricted by a long-term reduction in
the injectivity of the reinjection well.
Nomenclature

2
A cross-section area (m )
Forchheimer coefficients (m)
a 1 , a 2
b fracture aperture (m)
C a forth-order elasticity tensor (−)
−1
c specific heat capacity of porous medium (J kg −1 K )
hydraulic radius (m)
D h
E Young’s modulus (Pa)
f (n) porosity function (−)
G shear modulus (Pa)
−2
g gravity acceleration vector (m s )
h lag distance in Variogram model (m)
I identity tensor
2
k, k intrinsic permeability (tensor) (m )
−1
K hydraulic conductivity (m s )
K r coefficient of restraint (−)
L characteristic length scale (m)
n porosity
n normal vector
p fluid pressure (Pa)
−1
q f specific flow rate (s )
3
−1
Q f volumetric flow rate (m s )
Q T heat source (J m −3 K)
−1
S s specific storage (Pa )
t time (s)
T temperature (K)
u solid displacement vector (m)
−1
v fluid phase velocity (m s )
x, y, z coordinates (m)
Greek Symbols

α b Biot’s constant (-)
−1
β p compressibility coefficient (Pa )
−1
β T thermal expansion coefficient (K )
−1
3
β C coefficient of expansivity due to solute concentration (m kg )
δ ij Kronecker delta
increment()
ε strain tensor