CO2 and brine models¶

Summary¶

The equation-of-state and viscosity of CO2 under both sub- and super-critical conditions are computed as a function of both pressure and temperature, using the empirical equations developed by Span & Wagner (1996) and Fenghour & Wakeman (1998), respectively.

The brine density, which depends on pressure, temperature, and salinity, is calculated based on the correlation developed by Phillips et al. (1981).

Function Description¶

Function of CO2 density calculation

double PVTPackage::CO2Model::ComputeMassDensity(double P, double T)

input parameters:

P - pressure (Pa), P < 800 MPa
T - temperature (K) 200K <= T <= 1100K

return parameter:

density ( $\text{kg/m}^3$ )

Function of CO2 viscosity calculation

double PVTPackage::CO2Model::ComputeVisc(double P, double T)

input parameters:

P - pressure (Pa), P < 300 MPa
T - temperature (K) 200K <= T <= 1500K

return parameter:

viscosity (Pa.s)

Function of brine density calculation

double PVTPackage::BrineModel::ComputeMassDensity(double P, double T, double salinity)

input parameters:

P - pressure (Pa), P <= 50 MPa
T - temperature (C), 10C <= T <= 350C
salinity - brine salinity, (molal) salinity <= 5 molal

return parameter:

density ( $\text{kg/m}^3$ )

References¶

A. Fenghour & W. A. Wakeman, The viscosity of carbon dioxide, J. Phys. Chem. Ref. Data, vol. 27, pp. 31-44, 1998.
S. L. Phillips et al., A technical databook for geothermal energy utilization, Lawrence Berkeley Laboratory report, 1981.
R. Span & W. Wagner., A new equation of state for carbon dioxide covering the fluid region from the triple-point temperature to 1100 K at pressure up to 800 MPa, J. Phys. Chem. Ref. Data, vol. 25, pp. 1509-1596, 1996.