Density and viscosity of brine: An overview from a process engineers perspective

Abstract

The aim of our study is to evaluate the sensitivity of the volumetric flow rate of a downhole pump in a geothermal production well on different density and viscosity functions during the startup and stationary operating phases.The geothermal fluid is modeled as an aqueous sodium chloride solution and functions for its density and viscosity are compared and applied to a model of the geothermal fluid cycle. It is shown that the deviations between viscosity functions have negligible impact on the the volumetric flow rate, while the impact of the deviations between different density functions is up to 54 % of the volumetric flow rate.

Ways to Minimize Water Usage in Engineered Geothermal Systems

“…5 TDS brine has a viscosity of 0.0018 Pa·s at 25C that drops to 0.0003 Pa·s at 190C (Franke & Thorade 2010). Calculation of flow rate versus permeability shows that the hydraulic head has the greatest effect on the flow rate through the rock.…”

“…The salinity of groundwater at geothermal sites can range from about 6000 ppm chloride ion, such as in the Berlin field, El Salvador (D'Amore & Mejia 1999), to 18,000 ppm in California at a depth of about 2 km (Rogers & Dreiss 1995), to 2x10 5 total dissolved solids (TDS) measured in German samples (4200m, 150C, 45 MPa) (Regenspurg, Wiersberg et al 2010). The composition of the geothermal water changes over time with production but, except at the highest TDS, can be considered to be primarily NaCl (aq) (Franke & Thorade 2010). The viscosity does not change much with subsurface pressure, but models show an exponential drop in viscosity with temperature.…”

Two-dimensional THM modelling of the large scale natural hydrothermal circulation at Soultz-sous-Forêts

“…Several other models exist in the literature, see, e.g. the review of Francke and Thorade (2010), but Equation (13) has been used because it is the law implemented in Code_Aster. Equation (13) can be rewritten in the following integral form:…”

Geochemical and Process Engineering Challenges for Geothermal Power Generation

“…For more complex fluid compositions the derivation and evaluation of mixing rules will require an ongoing experimental effort. Referring to the Groß Schönebeck site, laboratory measurements of density, viscosity, and electrical conductivity [17] as well as first calculations based on existing fluid property correlations [18] were performed. At the GFZ, nationally funded research is conducted on developing experimental methods, the physical properties of complex fluids, and interrelations between thermophysical parameters and chemical reactions.…”