Page 279 - Formulas and Calculations for Petroleum Engineering

272 Formulas and calculations for petroleum engineering

5.32 Diffusion potential

Input(s)
t Cl : Chlorine Anion Transference Number (dimensionless)
R: Gas Constant (8.31) (J/mol K)
T a : Absolute Temperature (degree K)
F: Faraday Constant (96516) (C)
a 1 : Activities of 1st Electrolyte (dimensionless)
a 2 : Activities of 2nd Electrolyte (dimensionless)

Output(s)
E d : Diffusion Potential (V)

Formula(s)

T a a 1
E ¼ 2 t 1Þ R ln
ð
d Cl
F a
2
Reference: Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4.
Chapter 6, Page: 130.

5.33 Diffusion through a non-isothermal spherical film
Input(s)

P: Pressure (atm)
2
D AB : Diffusivity (cm /s)
R: Gas Constant (J/mol K)
T 1 : Temperature (K)
n: Exponent (dimensionless)
r 1 : Radius of Gas Film (cm)
r 2 : Radius of Film (cm)
x A1 : Position of Gas (fraction)
x A2 : Position of Film (fraction)

Output(s)
W A : Mass Rate (mol/s)

Formula(s)

P D
n
4 p AB 1+
R T 1 2 1 x A2
W ¼ n n ! ln
A
n 1 2 1 2 1 x A1
1+ 1+
r 2
1
r r
1 2
Reference: Bird, R.B., Stewart, W.E. and Lightfoot, E.N. (2002). Transport Phenomena (Second Ed.). John Wiley & Sons,
Chapter: 18, Page: 551.