Phase Behavior and ThermodynamicsPVT Properties
Average Compressibility of Oil Formula
Average Compressibility of Oil calculates average oil compressibility for pvt properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (V, V_1, V_2, p_1, p_2) are known and the assumptions behind the cited pvt properties 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_o equals 0.00002 1/psi.
Vfraction
1
V_1fraction
0.98
V_2fraction
1
p_1psi
4000
p_2psi
3000
Inputs
V
fractionReference Volume
V_1
fractionVolume Fraction at Higher Pressure
V_2
fractionVolume Fraction at Lower Pressure
p_1
psiHigher Pressure
p_2
psiLower Pressure
Outputs
C_o
1/psi
Average Oil Compressibility
V
fraction
Reference Volume
V_1
fraction
Volume Fraction at Higher Pressure
V_2
fraction
Volume Fraction at Lower Pressure
p_1
psi
Higher Pressure
p_2
psi
Lower Pressure
Source and review
reviewedCraft, B.C., Hawkins, M. and Terry, R.E. 1991. Applied Petroleum Reservoir Engineering, 2nd Edition, Page 38.
Source