Production EngineeringInflow Performance
Flow Coefficient During Drawdown Formula
Flow Coefficient During Drawdown calculates flow coefficient during drawdown for inflow performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (P_i, p_wf, DeltaP_skin) are known and the assumptions behind the cited inflow 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, E equals 0.7 fraction.
P_ipsi
3500
p_wfpsi
2500
DeltaP_skinpsi
300
Inputs
P_i
psiAverage Reservoir Pressure
p_wf
psiWellbore Flowing Pressure
DeltaP_skin
psiPressure Drop Due to Skin
Outputs
E
fraction
Flow Coefficient During Drawdown
DeltaP_skin
psi
Pressure Drop Due to Skin
P_i
psi
Average Reservoir Pressure
p_wf
psi
Wellbore Flowing Pressure
Source and review
reviewedAhmed, T. and McKinney, P.D. 2005. Advanced Reservoir Engineering. Gulf Publishing / Elsevier, Chapter 1, Page 64.
Source