Table 3 Symbols and descriptions of thermodynamic parameters used in this study
Symbol | Definition | Values | References |
|---|---|---|---|
\(\Delta V\) | Deflated volume | 7.0 × 105 m3 | Narita and Murakami (2018) |
\(\rho\) | Water bulk density | \(\rho = S\rho_{\text{l}} + \left( {1 - S} \right)\rho_{\text{v}}\) | – |
\(S\) | Volumetric liquid fraction | 0–1 | – |
\(\rho_{\text{l}}\) | Liquid water density | 688–777 kg/m3 | a |
\(\rho_{\text{v}}\) | Vapor density | 25–55 kg/m3 | a |
\(\beta_{\text{f}}\) | Water compressibility | Single phase: \(\frac{1}{\rho }\left( {\frac{{{\text{d}}\rho }}{{{\text{d}}P}}} \right)_{\text{h}}\) | b |
Two phases: \(\frac{\rho c}{\phi } \left[ {1.92 \times 10^{ - 6} P^{ - 1.66} } \right]\)d | Grant and Sorey (1979) | ||
\(P\) | Pressure | 5–10 MPa | – |
\(T\) | Temperature | 264–311 °C |  |
\(\phi\) | Porosity | 0.1–0.5 | – |
\(\left\langle {\rho c} \right\rangle\) | Volumetric heat capacity of the wetted rock | \(\left( {1 - \phi } \right)\rho_{\text{r}} C_{\text{r}} + \phi S\rho_{\text{l}} C_{\text{l}}\) | Grant and Sorey (1979) |
\(\rho_{\text{r}}\) | Host rock density | 2000 kg/m3 | – |
\(C_{\text{r}}\) | Isobaric specific heat of host rock | 1 kJ/kg/°C | – |
\(C_{\text{l}}\) | Isobaric specific heat of liquid water | 5.0–6.1 kJ/kg/ °C | a |
\(\beta_{\text{c}}\) | Compressibility of the pressure source | 1.4 × 10−8–10−9 Pa−1 | c |