Reservoir EngineeringPressure Transient Analysis
True Wellbore Storage Coefficient for Pressure Buildup Test Formula
True Wellbore Storage Coefficient for Pressure Buildup Test calculates true wellbore storage coefficient for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (A_wb, rho_wb) 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, C_wb equals 0.1026 bbl/psi.
A_wbft^2
0.2
rho_wblbm/ft^3
50
Inputs
A_wb
ft^2Wellbore Cross-Sectional Area
rho_wb
lbm/ft^3Wellbore Fluid Density
Outputs
C_wb
bbl/psi
True Wellbore Storage Coefficient
A_wb
ft^2
Wellbore Cross-Sectional Area
rho_wb
lbm/ft^3
Wellbore Fluid Density
Source and review
reviewedLee, J., Rollins, J. B., and Spivey, J. P. Pressure Transient Testing, SPE Textbook Series Vol. 9, Page 105.
Source