Pseudosteady-State Radial Liquid Flow Rate Formula
Pseudosteady-State Radial Liquid Flow Rate calculates pseudosteady-state liquid flow rate for permeability and flow workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k, h, P_i, P_wf, B, mu, r_e, r_w) are known and the assumptions behind the cited permeability and flow relationship match the engineering case being checked.
Assumptions
- Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
- The declared units match the field-unit constants used in the formula.
- The cited formula applies to the selected petroleum engineering workflow.
Limitations
- The calculation does not replace a full engineering model or operating procedure.
- Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.
Common mistakes
- Mixing unit systems without converting the inputs.
- Using default example values as field recommendations.
- Applying the formula outside the source assumptions.
Default example
Using the default inputs, Q equals 977.591659 STB/day.
50
50
3500
2500
1.2
2
1000
0.25
Inputs
k
mDPermeability
h
ftReservoir thickness
P_i
psiAverage reservoir pressure
P_wf
psiBottomhole flowing pressure
B
bbl/STBFormation volume factor
mu
cPFluid viscosity
r_e
ftDrainage radius
r_w
ftWellbore radius
Outputs
Q
Pseudosteady-state liquid flow rate
k
Permeability
h
Reservoir thickness
P_i
Average reservoir pressure
P_wf
Bottomhole flowing pressure
B
Formation volume factor
mu
Fluid viscosity
r_e
Drainage radius
r_w
Wellbore radius
Source and review
reviewedAhmed, T. and McKinney, P. D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 1, Page 33.
Source