News & Events
- July 15th, 2008Flowasta released
Viscosity
Hydrate formation will make the apparent viscosity increase, which will also make the pressure drop and liquid hold-up increase. The pressure drop in a pipeline with hydrate formation may be so high that the flow stops and the pipeline effectively gets plugged.
Oil, gas and water viscosities
Depending on which viscosity model was selected in PVTsim when the fluid was prepared, Flowasta determines gas and oil viscosities using either the corresponding states model (Pedersen et al. (1984 and 1987) and Lindeloff et al. (2004)) or the LBC model (Lohrenz et al., 1964).
The water viscosity is calculated using correlations specific for water (Meyer et al. (1967) and Schmidt (1969)).
Slurry Viscosity
The viscosities of hydrate slurries are calculated from a correlation that takes into consideration the volumetric as well as the non-Newtonian (shear rate dependent) effects of solids (Pedersen and Rønningsen, 2000).
ηliq and ηsusp denote respectively the liquid and suspension viscosities not considering the influence of shear rate. The shear rate (dvx/dy) dependence enters through the last two terms in the above equation where Φ is the hydrate volume fraction.
The solids suspension viscosity is calculated from the Thomas (1965) model for hydrates suspended in water
Con1 – Con4 and Con6-Con7 are constants given in the listed references.
