# Isothermal compressibility of oil - Villena-Lanzi correlation - P<Pb

## Input(s)

p: Pressure (psi)

\(p_{b}\): Bubble point pressure (psi)

T: Temp \((\mathrm{F})\)

Rsob: Solution oil gas ratio at bubble point (fraction)

\(\rho\): Density of oil (API)

## Output(s)

\(l c_{o}\): Isothermal Compressibility of Oil (/psi)

## Formula(s)

\[
l c_{o}=-0.664-1.430 * \ln (p)-0.395 * \ln \left(p_{b}\right)+0.39 * \ln (T)+0.455 * \ln (R s o b)+0.262 * \ln (\rho)
\]

## Reference(s)

Applied Petroleum Reservoir Engineering, Second Edition, Craft & Hawkins, Page: 39.