Page 11 - Formulas and Calculations for Petroleum Engineering

4 Formulas and calculations for petroleum engineering

1.3 Average permeability for linear flow—Series beds

Input(s)
k 1 : Permeability for layer 1 (mD)
k 2 : Permeability for layer 2 (mD)
k 3 : Permeability for layer 3 (mD)
L 1 : Length of layer 1 (ft)
L 2 : Length of layer 2 (ft)
L 3 : Length of layer 3 (ft)

Output(s)
k avg : Average Permeability in Linear Systems Series (mD)

Formula(s)

L + L + L 3
2
1
k avg ¼
L
1 + L 2 + L 3
k 1 k 2 k 3
Reference: Ahmed, T. (2006). Reservoir Engineering Handbook. Elsevier, Page: 240.

1.4 Average permeability for parallel-layered systems
Input(s)

k 1 : Permeability for Layer 1 (mD)
k 2 : Permeability for Layer 2 (mD)
k 3 : Permeability for Layer 3 (mD)
h 1 : Height of Layer 1 (ft)
h 2 : Height of Layer 2 (ft)
h 3 : Height of Layer 3 (ft)

Output(s)
k avg : Average Permeability for Parallel-layered Systems (mD)

Formula(s)

k h + k h + k h 3
1
3
2
2
1
k avg ¼
h + h + h 3
1
2
Reference: Ahmed, T. (2006). Reservoir Engineering Handbook. Elsevier, Page: 237.
1.5 Average permeability in radial systems
Input(s)
k a : Permeability between r w and r a (mD)
k e : Permeability between r e and r a (mD)
r e : Drainage radius (ft)
r w : Well bore radius (ft)
r a : Radius lesser than r e (ft)