Infinite-Acting Pseudoradial Bottomhole Flowing Pressure Formula
Infinite-Acting Pseudoradial Bottomhole Flowing Pressure calculates bottomhole flowing pressure for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (p_i, Q_o, B_o, mu_o, k, h, t, phi, c_t, r_w, S) are known and the assumptions behind the cited pressure transient analysis 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, P_wf equals 3,835.843788 psi.
4000
500
1.2
1
100
50
10
0.2
0.00001
0.25
2
Inputs
p_i
psiInitial Reservoir Pressure
Q_o
STB/dayOil Flow Rate
B_o
bbl/STBOil Formation Volume Factor
mu_o
cPOil Viscosity
k
mDPermeability
h
ftFormation Thickness
t
hFlowing Time
phi
fractionPorosity
c_t
1/psiTotal Compressibility
r_w
ftWellbore Radius
S
dimensionlessSkin Factor
Outputs
P_wf
Bottomhole Flowing Pressure
p_i
Initial Reservoir Pressure
Q_o
Oil Flow Rate
B_o
Oil Formation Volume Factor
h
Formation Thickness
S
Skin Factor
Source and review
reviewedAdvanced Reservoir Engineering, Ahmed, T., McKinney, P. D. (2005)
Ahmed, T. and McKinney, P. D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 1, Page 98.
Source