Reservoir EngineeringPressure Transient Analysis
Time to End of Infinite-Acting Period in Circular Reservoir Formula
Time to End of Infinite-Acting Period in Circular Reservoir calculates time to end of infinite-acting period for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (phi, mu, c_t, A, k) 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_eia equals 3.31056 h.
phifraction
0.2
mucP
1
c_t1/psi
0.00001
Aft^2
435600
kmD
100
Inputs
phi
fractionPorosity
mu
cPViscosity
c_t
1/psiTotal Compressibility
A
ft^2Well Drainage Area
k
mDPermeability
Outputs
t_eia
h
Time to End of Infinite-Acting Period
phi
fraction
Porosity
mu
cP
Viscosity
c_t
1/psi
Total Compressibility
A
ft^2
Well Drainage Area
k
mD
Permeability
Source and review
reviewedAhmed, T. and McKinney, P.D. 2005. Advanced Reservoir Engineering, Chapter 1, Page 50.
Source