TY - JOUR

T1 - Thermal-hydrodynamic-chemical (THC) modeling based on geothermal field data

AU - Kiryukhin, Alexey

AU - Xu, Tianfu

AU - Pruess, Karsten

AU - Apps, John

AU - Slovtsov, Igor

N1 - Funding Information: The authors would like to express their gratitude for helpful discussions to G. Bodvarsson, A. Simmons, A. Truesdell, R. Fournier, M. Reed, N. Spycher, S. Fedotov,V. Belousov, S. Flexser, M. Lippmann, E. Sonnenthal, K. Williamson, P. Kruger, P. Dobson, M. Hanano, T. Shimoike, E. Lima, M. Momita, N. Tsuchiya, L. Richard, S. Salah and E. Kalacheva. This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Power Technologies, Office of Wind and Geothermal Technologies, of the US Department of Energy, under contract No. DE-ACO3-76SF00098; and by the Russia Foundation Basic Research grant 03-05-65373, and Far East Branch, Russia Academy of Sciences grant 03-3-A-08-069.

PY - 2004/6

Y1 - 2004/6

N2 - Data on fluid chemistry and rock mineralogy are evaluated for a number of geothermal fields located in the volcanic arc of Japan and Kamchatka, Russia, Common chemical characteristics are identified and used to define scenarios for detailed numerical modeling of coupled thermal-hydrodynamic-chemical (THC) processes. The following scenarios of parental geothermal fluid upflow were studied: (1) single-phase conditions, 260 °C at the bottom ('Ogiri' type); (2) two-phase conditions, 300 °C at the bottom ('Hatchobaru' type); and (3) heat pipe conditions, 260 °C at the bottom ('Matsukawa' type). THC modeling for the single-phase upflow scenario shows wairakite, quartz, K-feld spar and chlorite formed as the principal secondary minerals in the production zone, and illite-smectite formed below 230 °C. THC modeling of the two-phase upflow shows that quartz, K-feldspar (microcline), wairakite and calcite precipitate in the model as principal secondary minerals in the production zone. THC modeling of heat pipe conditions shows no significant secondary deposition of minerals (quartz, K-feldspar, zeolites) in the production zone. The influence of thermodynamic and kinetic parameters of chemical interaction, and of mass fluxes on mineral phase changes, was found to be significant, depending on the upflow regime. It was found that no parental geothermal fluid inflow is needed for zeolite precipitation, which occurs above 140 °C in saturated andesite, provided that the porosity is greater than 0.001. In contrast, quartz and K-feldspar precipitation may result in a significant porosity reduction over a hundred-year time scale under mass flux conditions, and complete fracture sealing will occur given sufficient time under either single-phase or two-phase upflow scenarios. A heat pipe scenario shows no significant porosity reduction due to lack of secondary mineral phase deposition.

AB - Data on fluid chemistry and rock mineralogy are evaluated for a number of geothermal fields located in the volcanic arc of Japan and Kamchatka, Russia, Common chemical characteristics are identified and used to define scenarios for detailed numerical modeling of coupled thermal-hydrodynamic-chemical (THC) processes. The following scenarios of parental geothermal fluid upflow were studied: (1) single-phase conditions, 260 °C at the bottom ('Ogiri' type); (2) two-phase conditions, 300 °C at the bottom ('Hatchobaru' type); and (3) heat pipe conditions, 260 °C at the bottom ('Matsukawa' type). THC modeling for the single-phase upflow scenario shows wairakite, quartz, K-feld spar and chlorite formed as the principal secondary minerals in the production zone, and illite-smectite formed below 230 °C. THC modeling of the two-phase upflow shows that quartz, K-feldspar (microcline), wairakite and calcite precipitate in the model as principal secondary minerals in the production zone. THC modeling of heat pipe conditions shows no significant secondary deposition of minerals (quartz, K-feldspar, zeolites) in the production zone. The influence of thermodynamic and kinetic parameters of chemical interaction, and of mass fluxes on mineral phase changes, was found to be significant, depending on the upflow regime. It was found that no parental geothermal fluid inflow is needed for zeolite precipitation, which occurs above 140 °C in saturated andesite, provided that the porosity is greater than 0.001. In contrast, quartz and K-feldspar precipitation may result in a significant porosity reduction over a hundred-year time scale under mass flux conditions, and complete fracture sealing will occur given sufficient time under either single-phase or two-phase upflow scenarios. A heat pipe scenario shows no significant porosity reduction due to lack of secondary mineral phase deposition.

KW - Geothermal fields

KW - Japan

KW - Kamchatka

KW - Modeling

KW - Russia

KW - TOUGHREACT

UR - http://www.scopus.com/inward/record.url?scp=2142699538&partnerID=8YFLogxK

U2 - 10.1016/j.geothermics.2003.09.005

DO - 10.1016/j.geothermics.2003.09.005

M3 - Article

AN - SCOPUS:2142699538

VL - 33

SP - 349

EP - 381

JO - Geothermics

JF - Geothermics

SN - 0375-6505

IS - 3

ER -