calculate
Faltaflo Model Sensitivity
Model Input Model Output
To use:
3
Base case values Definitions units Adjust the base case values in blue in the box on t (min) t (sec) tau G(tau) Q (m /s) Q (l/min) Q(cfm)
radial
2
your left as you need. Then look at the box on
kr = 3.96E-11 permeability m your right for the answer in yellow.The 10 minute 0.0167 1 233.88 0.3192 0.0434 2604.22 91.96
mug = 1.83E-05 viscosity kg/msec value is generally the one I use. 0.1667 10 2338.8 0.2334 0.0317 1904.38 67.25
phi = 0.4 porosity 1.6667 100 23388 0.1840 0.0250 1501.01 53.00
Gas phase
Sg = 0.9 saturation In this example, actual values from the SRS A/M area are 10 600 140328 0.1579 0.0215 1288.62 45.50
Pavg = 100400 Average P Pa used which have resulted in measured flows approximately 166.67 10000 2E+06 0.1292 0.0176 1054.36 37.23
rw = 0.0508 Well radius m equal to the predicted flow (45 scfm) 1666.7 100000 2E+07 0.1125 0.0153 917.80 32.41
b= 20 zone thickness m 8333.3 5.00E+05 1E+08 0.1032 0.0140 841.62 29.72
Pressure
Swb = Pdiff = 500 differential Pa
kr 2 kr Pavg t
tau factor = 233.8793 Equation for flow = Q = 2pb Swb with t= and G(t ) »
2
Q factor = 0.1360 mg ln( 2.25t ) jS g m g rw 2 ln (2.25t )
kr (Darcy's) = 40.0000
time (sec) = 600
Tau = 1.40E+05
G(tau) = 1.58E-01
FALTAFLO_sens
FALTAFLO
Faltaflo Model Sensitivity
Model Input Model Output
3
Base case values Definitions units t (min) t (sec) tau G(tau) Q (m /s) Q (l/min) Q(cfm)
radial
2
kr = 9.90E-12 permeability m 0.0167 1 3367.9 0.22 0.000789 47.31 1.670552
mug = 1.83E-05 viscosity kg/msec 0.1667 10 33679 0.18 0.000627 37.614 1.328193
phi = 0.4 porosity 1.6667 100 336786 0.15 0.00052 31.217 1.102292
Gas phase
Sg = 0.25 saturation 10 600 2E+06 0.13 0.000459 27.568 0.973456
Pavg = 100400 Average P Pa 166.67 10000 3E+07 0.11 0.000388 23.293 0.822506
rw = 0.0127 Well radius m 1666.7 100000 3E+08 0.1 0.000345 20.67 0.729877
b= 1 zone thickness m 8333.3 5.00E+05 2E+09 0.09 0.000319 19.162 0.676616
Pressure
Swb = Pdiff = 1036 differential Pa
kr 2 kr Pavg t
tau factor = 3367.8616 Equation for flow = Q = 2pb Swb with t= and G(t ) »
2
Q factor = 0.0035 mg ln( 2.25t ) jS g m g rw 2 ln (2.25t )
kr (Darcy's) = 10.0000
Sensitivity analysis
Vary kr , phi, Sg , Pavg , rw, b, Pd iff and look at variance from base case
Radial Permeability Porosity Gas Phase Saturation Average Pressure Well Radius Zone Thickness Pressure Differential
2 2
k r (m ) Q(cfm) variance phi Q(cfm) variance Sg Q(cfm) variance Pavg (Pa) Q(cfm) variance rw (m ) Q(cfm) variance b (m) Q(cfm) variance Pdiff (Pa) Q(cfm) variance
1.00E-13 1.34E-02 99% 0.25 9.15E-01 6% 0.1 8.91E-01 9% 98500 9.43E-01 3% 0.0125 9.40E-01 3% 1 9.42E-01 3% 50 4.55E-02 95%
5.00E-13 5.86E-02 94% 0.3 9.25E-01 5% 0.2 9.29E-01 5% 99000 9.43E-01 3% 0.0254 1.03E+00 6% 2 1.88E+00 94% 100 9.09E-02 91%
1.00E-12 1.11E-01 89% 0.35 9.34E-01 4% 0.3 9.53E-01 2% 99500 9.43E-01 3% 0.0379 1.09E+00 12% 5 4.71E+00 384% 200 1.82E-01 81%
5.00E-12 4.97E-01 49% 0.4 9.42E-01 3% 0.4 9.71E-01 0% 100000 9.42E-01 3% 0.0508 1.14E+00 17% 10 9.42E+00 868% 300 2.73E-01 72%
1.00E-11 9.51E-01 2% 0.45 9.49E-01 2% 0.5 9.85E-01 1% 100500 9.42E-01 3% 20 1.88E+01 1836% 400 3.64E-01 63%
5.00E-11 4.32E+00 343% 0.5 9.56E-01 2% 0.6 9.97E-01 2% 101000 9.42E-01 3% 30 2.83E+01 2803% 500 4.55E-01 53%
1.00E-10 8.30E+00 753% 0.55 9.61E-01 1% 0.7 1.01E+00 4% 101500 9.41E-01 3% 600 5.46E-01 44%
0.8 1.02E+00 4% 102000 9.41E-01 3% 700 6.37E-01 35%
FALTAFLO_sens