Page 506 - Enhanced Oil Recovery in Shale and Tight Reservoirs

470 Nomenclature

2
2
H t release heat (enthalpy) at any time, mL /t ,J
I w wetting index, fraction
2
k permeability, L ,mD
K K value, dimensionless
2
k 0 permeability at the initial stress s 0 ,L , mD,
k effective permeability of two phases at S wf ,mD
e
k r relative permeability, dimensionless, fraction
l imbibition distance, L, m
L length, L, ft
L a characteristic length, ft
L c critical and characteristic length, ft
M molecular weight, m, g
3
M e effective mobility, L t/m
m t mass, m, kg
n reaction order or exponent in a k r equation, dimensionless
N B bond number, dimensionless
N C capillary number, dimensionless
(N C ) C critical capillary number, dimensionless
(N C ) max maximum capillary number, dimensionless
N pe Péclet number, dimensionless
N T trapping number, dimensionless
2
p pressure, m/Lt , kPa, atm., psi
2
p avg matrix average pressure, m/Lt , kPa
2
p c capillary pressure, m/Lt , psi
P D dimensionless pressure
2
P e capillary pressure at Swf, m/Lt , psi
p huff dimensionless pressure during the huff time
p max maximum matrix average pressure in one cycle, psi
2
p partial pressure of oxygen, m/Lt , kPa
O 2
p puff dimensionless pressure during the puff time
p vapor pressure of the pure water component, m/Lt 2
w
2
2
Q gross calorific value per unit mass of burned fuel, L /t , cal/g in Eq. 13.9, or heat
2
2
of reaction per unit mass of fuel, L /t , J/mole in Eq. 13.13
' 2 2
Q gross calorific value of per unit mass of burned fuel, L /t , BTU/lb in Eq. 13.10
3
2
Q heat of reaction in terms of the oxidizer, m/Lt , kcal/mol O 2 or BTU/ft air in
Eq. 13.11
2
2
Q enthalpy of the oxidation reaction, L /t , kJ/mol
O 2
r capillary or pore radius, L, m
R recovery factor by spontaneous water imbibition, or gas the constant (8.3147 J/

( K∙mol)) or 0.082 (liter∙atm)/( K∙mol))
R normalized oil recovery, dimensionless
RF oil recovery factor, fraction or %
r w water drop radius, L
3
3
S saturation, L /L , fraction
S 1 area representing the integral of average matrix pressure over the huff time (t huff )
in a cycle, m/Lt, psi$hour