Dimensionless Pressure for Linear Flow Constant Rate General Case Formula
Dimensionless Pressure for Linear Flow Constant Rate General Case calculates dimensionless linear flow pressure for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k, A, 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 62.210373 dimensionless.
50
100000
4000
3500
500
1.2
1.5
Inputs
k
mDEffective Permeability
A
ft^2Drainage Area
p_i
psiInitial Reservoir Pressure
p
psiPressure at Time of Interest
q
STB/dayLiquid Flow Rate
B
rb/STBFormation Volume Factor
mu
cPFluid Viscosity
Outputs
p_D
Dimensionless Linear Flow Pressure
k
Effective Permeability
A
Drainage Area
p_i
Initial Reservoir Pressure
p
Pressure at Time of Interest
q
Liquid Flow Rate
B
Formation Volume Factor
mu
Fluid Viscosity
Source and review
reviewedLee, Rollins and Spivey, Pressure Transient Testing, SPE Textbook Series Vol. 9, linear-flow constant-rate dimensionless variables.
Source