Villena-Lanzi Saturated Oil Compressibility Formula
Villena-Lanzi Saturated Oil Compressibility calculates saturated oil compressibility for pvt properties workflows in phase behavior and thermodynamics.
How engineers use this formula
Use this formula when the listed inputs (p, p_b, T, R_sb, API) 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 0.000106 1/psi.
2500
3000
180
600
35
Inputs
p
psiaCurrent Pressure Below Bubble Point
p_b
psiaBubble Point Pressure
T
deg FReservoir Temperature
R_sb
SCF/STBSolution Gas-Oil Ratio at Bubble Point
API
APIOil API Gravity
Outputs
c_o
Saturated Oil Compressibility
p
Current Pressure Below Bubble Point
p_b
Bubble Point Pressure
T
Reservoir Temperature
R_sb
Solution Gas-Oil Ratio at Bubble Point
API
Oil API Gravity
Source and review
reviewedOil Compressibility Correlations, Villena-Lanzi, M., Petroleum Office
Villena-Lanzi, M. 1985. A Correlation for the Coefficient of Isothermal Compressibility of Black Oil at Pressures Below the Bubblepoint, M.S. Thesis, University of Tulsa; Petroleum Office oil-compressibility documentation.
Source