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Oil Viscosity Calculator

Calculate dead oil, live (saturated) oil, and undersaturated oil viscosity using Beggs-Robinson and Vasquez-Beggs correlations.

Input Parameters

Beggs-Robinson (dead oil) + Beggs-Robinson (live oil) + Vasquez-Beggs (undersaturated)

Dead Oil Viscosity

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cp

Live Oil Viscosity (at Pb)

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cp

Viscosity at Pressure

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cp

Condition

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How this was calculated

Dead Oil (Beggs-Robinson): x = T^(-1.163) * exp(6.9824 - 0.04658*API); μod = 10^x - 1

Live Oil (Beggs-Robinson): A = 10.715*(Rs+100)^(-0.515); B = 5.44*(Rs+150)^(-0.338); μob = A * μod^B

Undersaturated (Vasquez-Beggs): m = 2.6*P^1.187 * exp(-11.513 - 8.98e-5*P); μo = μob * (P/Pb)^m

When P ≤ Pb, the oil is saturated and Rs at pressure is used. When P > Pb, the undersaturated correction is applied.

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Understanding Oil Viscosity Correlations

Oil viscosity is one of the most important fluid properties in petroleum engineering, directly affecting flow rates, pressure drops, and recovery efficiency. Because direct laboratory measurements are not always available, correlations are widely used. The Beggs-Robinson correlation (1975) is one of the most popular methods for estimating dead oil and live (saturated) oil viscosity.

Dead oil viscosity (gas-free oil) depends primarily on API gravity and temperature. As dissolved gas is added, viscosity decreases significantly. The Beggs-Robinson correlation models this reduction as a function of solution gas-oil ratio (Rs). For pressures above the bubble point, all gas remains dissolved and viscosity increases with pressure. The Vasquez-Beggs (1980) correlation handles this undersaturated regime. This calculator implements all three stages. All calculations run in your browser. Built by Groundwork Analytics.

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.