Measurements and correlation of Mexican heavy dead crude oil viscosities

• This work presents viscosity measurements of heavy oil from Mexican reservoirs.
• Viscosity was measured using a constant force electromagnetic viscometer.
• Dynamic viscosities of heavy oils were obtained at a wide temperature range.
• An uncertainty on μ less than ±1.0% over the temperature range was found.
• A new correlation was developed to estimate viscosities of Mexican heavy oils.

This work presents reliable measurements for dynamic viscosity of representative heavy oil samples from Mexican reservoirs. Most of the experimental data of dynamic viscosity were measured using a constant force electromagnetic viscometer. The viscometer was calibrated using several viscosity standards based on a maximum standard deviation of 0.5% in all measurements for the three pistons used. Dynamic viscosities of heavy dead crude oils were obtained at a temperature range from 397.1 to 300.8 K, viscosities in the range of 10.9–7476.7 cP, oil API gravity from 11.5 to 19.4, and at a constant pressure of 0.1 MPa. The estimated uncertainty on viscosity was less than ±1.0% over the temperature range of measurements. A new correlation approach was developed to estimate dynamic viscosities of Mexican heavy crude oils based on oil API gravity, and temperature.