Dimensionless Time for Fracture Linear Flow Formula
Dimensionless Time for Fracture Linear Flow calculates dimensionless time based on fracture half-length for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k, t, phi, mu, c_t, L_f) 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, t_LfD equals 1.627778 dimensionless.
50
24
0.18
1.2
0.00001
300
Inputs
k
mDEffective Permeability
t
hrElapsed Flow Time
phi
fractionPorosity
mu
cPFluid Viscosity
c_t
1/psiTotal Compressibility
L_f
ftFracture Half-Length
Outputs
t_LfD
Dimensionless Time Based on Fracture Half-Length
k
Effective Permeability
t
Elapsed Flow Time
phi
Porosity
mu
Fluid Viscosity
c_t
Total Compressibility
L_f
Fracture Half-Length
Source and review
reviewedLee, Rollins and Spivey, Pressure Transient Testing, SPE Textbook Series Vol. 9, hydraulically fractured well linear-flow dimensionless variables.
Source