Dimensionless Shut-In Time for MDH Method Formula
Dimensionless Shut-In Time for MDH Method calculates dimensionless shut-in time based on drainage area for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (k, Delta_t, phi, mu, c_t, A) 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, Delta_t_DA equals 1.465 dimensionless.
50
24
0.18
1.2
0.00001
100000
Inputs
k
mDPermeability
Delta_t
hTotal Shut-In Time
phi
fractionPorosity
mu
cPFluid Viscosity
c_t
1/psiTotal Compressibility
A
ft^2Drainage Area
Outputs
Delta_t_DA
Dimensionless Shut-In Time Based on Drainage Area
k
Permeability
Delta_t
Total Shut-In Time
phi
Porosity
mu
Fluid Viscosity
c_t
Total Compressibility
A
Drainage Area
Source and review
reviewedAhmed, T. and McKinney, P. D. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 1, Page 59.
Source