| Title | Model Study of Formation of the Cap Rocks for Geothermal System Using ChemTOUGH2 |
|---|---|
| Authors | Sato, T., Sato, M.. Ueda, A., Kato, K.. Kissling, W.M., and White, S.P. |
| Year | 2005 |
| Conference | World Geothermal Congress |
| Keywords | reservoir, modeling, geochemical, cap rock, TOUGH2, ChemTOUGH |
| Abstract | We have developed numerical model of the geothermal system. The aim of this study is to simulate the formation of low permeability cap rocks. The reactive chemical transport simulator ChemTOUGH2 was used to model the kinetic reactions describing precipitation and dissolution of minerals. First, we developed a numerical model of the natural state of the geothermal system without considering the chemistry of the geothermal fluid. This model was then extended by including reservoir rock, alteration minerals and assuming a chemistry for the source water based on 12 component species. Using ChemTOUGH2 the evolution of fluid chemistry and rock alteration was traced for several thousand years. The model predicted, in keeping with observation, deposition of clay minerals at the top of the upflow area forming a low permeability cap. |