Production EngineeringWell Performance
Gas Pressure Testing Time for Unsteady Gas Flow Formula
Gas Pressure Testing Time for Unsteady Gas Flow calculates minimum test time for well performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (d_i, L_pipe, P_i) are known and the assumptions behind the cited well performance 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_m equals 0.384 h.
d_iin
8
L_pipemile
2
P_ipsi
1000
Inputs
d_i
inInternal Pipe Diameter
L_pipe
milePipe Length
P_i
psiInitial Test Pressure
Outputs
t_m
h
Minimum Test Time
d_i
in
Internal Pipe Diameter
L_pipe
mile
Pipe Length
P_i
psi
Initial Test Pressure
Source and review
reviewedGas Conditioning and Processing, Campbell, J.M. (1992)
Campbell, J.M. 1992. Gas Conditioning and Processing, Campbell Petroleum Series, Vol. 2, Page 30.
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