Normalizing mole compositional analysis is done to exclude H20 and other impurities such as N2, H2S, CO2, inert gases, etc.
Normalizing is required to calculate the properties of a raw natural gas after the H2S and CO2 have been removed at a gas plant. To determine how a gas will behave after the impurities are often removed, then you need to normalize the mixture without impurities.
The general procedure is:
-
Compute the total mole fraction of all components that are to be normalized, excluding the components that are to be ignored.
-
Divide the mole fraction of each component in the mixture by that sum
|
Component |
Mole Frac (yi) @ reservoir conditions |
Mole Frac (yi) @ Acid Free Gas |
Normalized Mole Frac (yi) |
|---|---|---|---|
|
C1 |
0.7 |
0.7 |
0.70/0.78 = 0.897 |
|
C2 |
0.05 |
0.05 |
0.05/0.78 = 0.064 |
|
C3+ |
0.03 |
0.03 |
0.03/0.78 = 0.039 |
|
H2S |
0.1 |
|
|
|
CO2 |
0.12 |
|
|
|
|
Sum = 1.0 |
Sum = 0.78 |
Sum = 1.00 |