Dimensionless Pressure - Radial Flow Constant-Rate Production Formula
Dimensionless Pressure - Radial Flow Constant-Rate Production calculates dimensionless pressure for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k, h, P_i, P, q, B, mu) 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_d equals 29.508971 dimensionless.
100
50
4000
3500
500
1.2
1
Inputs
k
mDPermeability
h
ftReservoir Thickness
P_i
psiInitial Reservoir Pressure
P
psiReservoir Pressure
q
STB/dayProduction Rate
B
RB/STBFormation Volume Factor
mu
cPOil Viscosity
Outputs
P_d
Dimensionless Pressure
k
Permeability
h
Reservoir Thickness
P_i
Initial Reservoir Pressure
P
Reservoir Pressure
q
Production Rate
B
Formation Volume Factor
mu
Oil Viscosity
Source and review
reviewedLee, J., Rollins, J.B. and Spivey, J.P. 2003. Pressure Transient Testing, SPE Textbook Series Vol. 9, Page 8.
Source