Testing geochemical modeling codes using New Zealand hydrothermal systems

Conference · Wed Dec 01 04:00:00 EST 1993

OSTI ID:10123674

Bruton, C J; Glassley, W E; Bourcier, W L

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of selected portions of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will: (1) ensure that we are providing adequately for all significant processes occurring in natural systems; (2) determine the adequacy of the mathematical descriptions of the processes; (3) check the adequacy and completeness of thermodynamic data as a function of temperature for solids, aqueous species and gases; and (4) determine the sensitivity of model results to the manner in which the problem is conceptualized by the user and then translated into constraints in the code input. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions. The kinetics of silica precipitation in EQ6 will be tested using field data from silica-lined drain channels carrying hot water away from the Wairakei borefield.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10123674
• Report Number(s): UCRL-JC--114798; CONF-9309228--9; ON: DE94006667
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150200
58 GEOSCIENCES
580000
99 GENERAL AND MISCELLANEOUS
990200
CHEMICAL REACTION KINETICS
COMPUTER CODES
GEOCHEMISTRY
GEOLOGY AND HYDROLOGY OF GEOTHERMAL SYSTEMS
GEOSCIENCES
Geothermal Legacy
HYDROTHERMAL SYSTEMS
MATHEMATICAL MODELS
MATHEMATICS AND COMPUTERS
THERMODYNAMIC ACTIVITY
WAIRAKEI GEOTHERMAL FIELD