Use this geological calculation for a transparent first-pass interpretation of measured rock, soil, fluid, well, stratigraphic, isotopic, geophysical, or seismic data under an explicitly selected model.

API gravity

Stock-tank oil gravity in degrees API.

Temperature (K)

Temperature of the oil.

Solution GOR

Solution gas-oil ratio in standard m³ per m³ of oil; zero yields the dead oil viscosity.

Compute dead and live oil viscosity with the Beggs-Robinson (1975) correlations. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Oil viscosity (Pa·s)

Live (or dead when Rs is zero) oil viscosity in pascal seconds.

Dead oil viscosity (Pa·s)

Dead oil viscosity at the given temperature in pascal seconds.

• Petroleum correlations are fluid-, pressure-, temperature-, and region-dependent. PVT sampling, phase behavior, relative permeability, capillary pressure, heterogeneity, aquifer support, well constraints, history match, and units affect forecasts and reserves.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Compare independent measurements and models, retain units and analytical metadata, propagate uncertainty, and validate interpretations against logs, cores, maps, laboratory data, or field observations.

• API Gravity Calculator

  Convert the specific gravity of crude oil at 60 degrees Fahrenheit to API gravity.

• Bubble Point Pressure Vasquez Beggs Calculator

  Invert the Vasquez-Beggs solution-GOR correlation to obtain the bubble point pressure; pass the separator-corrected gas gravity.

• Fold Wavelength Calculator

  Estimate the Biot–Ramberg dominant wavelength of a competent viscous layer as 2π times thickness times the cube root of the viscosity contrast divided by six.