← All Tools

PVT Properties Calculator

Calculate bubble point, solution GOR, oil FVF, viscosity, Z-factor, and more using Standing, Beggs-Robinson, and Hall-Yarborough correlations.

Reservoir Fluid Inputs

100% client-side. No data leaves your browser.

Oil Properties

Standing (1947) & Beggs-Robinson (1975)

Enter inputs and click Calculate to see results.

Gas Properties

Sutton (1985), Hall-Yarborough (1973) & Lee-Gonzalez-Eakin (1966)

Enter inputs and click Calculate to see results.

Oil FVF (Bo) vs Pressure

Solution GOR (Rs) vs Pressure

Oil Viscosity (μo) vs Pressure

Gas Z-factor vs Pressure

How this was calculated

Correlations used:

  • Bubble Point & Solution GOR: Standing (1947) — Pb = 18.2 × [(Rsg)^0.83 × 10^(0.00091T - 0.0125°API) - 1.4]
  • Oil FVF (Bo): Standing (1947) — Bo = 0.9759 + 12×10⁻⁵ × [Rsgo)^0.5 + 1.25T]^1.2
  • Oil Viscosity: Beggs & Robinson (1975) — dead oil + live oil correction
  • Z-Factor: Hall & Yarborough (1973) — Newton-Raphson iteration on reduced temperature/pressure
  • Gas Viscosity: Lee, Gonzalez & Eakin (1966)
  • Pseudocritical Properties: Sutton (1985)

Assumptions: Black oil model. No H₂S/CO₂ corrections. Separator conditions used for GOR correlation. Single-stage separation assumed.

When not to trust this: Volatile oils (API > 45), condensates, sour gas (>5% H₂S), temperatures above 350°F, or pressures above 10,000 psi. Lab PVT data should always take precedence.

Need help building a full-field PVT model or running compositional simulation? Our team combines Stanford-level reservoir engineering with modern data science to unlock value from your subsurface data.

Book a free strategy call →

What Are PVT Properties?

PVT (Pressure-Volume-Temperature) properties describe how reservoir fluids behave under changing conditions of pressure and temperature. Accurate PVT data is the foundation of every reservoir engineering study, from material balance analysis and decline curve forecasting to full-field numerical simulation. In the absence of laboratory PVT reports, engineers rely on empirical correlations developed from large datasets of measured fluid properties.

This free calculator implements the most widely used black-oil PVT correlations in the petroleum industry. Standing's correlation (1947) estimates bubble point pressure, solution gas-oil ratio (Rs), and oil formation volume factor (Bo) from API gravity, gas specific gravity, and reservoir temperature. Beggs and Robinson (1975) provide dead oil and live oil viscosity estimates that remain the industry standard for screening-level analysis.

For gas properties, we use Sutton's correlation (1985) to compute pseudocritical temperature and pressure, followed by the Hall-Yarborough method (1973) for the gas compressibility factor (Z-factor). The Hall-Yarborough equation of state is solved using Newton-Raphson iteration, providing accurate Z-factors across a wide range of reduced temperatures and pressures. Gas viscosity is calculated with the Lee, Gonzalez, and Eakin correlation (1966).

While these correlations are excellent for preliminary estimates and screening studies, laboratory PVT analysis remains essential for detailed reservoir characterization. If you need help interpreting PVT data, building equation-of-state models, or integrating fluid properties into your simulation workflow, contact Groundwork Analytics for a free consultation.

Related Tools

IPR Calculator — Plot IPR curves from your PVT data Oilfield Unit Converter — Convert between PE units

Disclaimer: These calculations are for screening and educational purposes only. Results should be verified against laboratory data, detailed simulation, or field measurements before making operational decisions. Groundwork Analytics assumes no liability for decisions made based on these results.