Study on the Rheology of CO2 Hydrate Slurry by Using the Capillary Method

The rheological properties of the CO2 hydrate slurry are experimentally investigated by using a new flow loop with an inner diameter of 50 mm. The pressure drops of the CO2 hydrate slurry are measured experimentally under the volumetric hydrate fraction, ranging from 1.4 to 17.2 vol%, and the shear rate ranging from 40 to 590 s(-1). Using the capillary method, the rheology of the CO2 hydrate slurry is analyzed based on pressure drop. The CO2 hydrate slurry is identified as a powerlaw fluid and exhibits strong shear-thickening behavior. The increase in the volumetric hydrate concentration not only ascends the apparent viscosity, but also makes the non-Newtonian behavior of the hydrate slurry become more obvious. The non-Newtonian index and the consistence factor of fluid increase exponentially with the volumetric hydrate concentration increasing. A Herschel- Bulkley-type rheological model of the CO2 hydrate slurry is correlated from experimental data. The developed model performs the average discrepancy of less than 16.3% within the range of the experiment.

Automated summary

The rheological properties of CO2 hydrate slurry were experimentally studied using a new flow loop. The slurry was found to be a powerlaw fluid with strong shear-thickening behavior. The increase in volumetric hydrate concentration not only increased the apparent viscosity, but also enhanced the non-Newtonian behavior.