https://doi.org/10.5194/hess-2018-624
https://doi.org/10.5194/hess-2018-624
| 08 Feb 2019
Status: this discussion paper is a preprint. It has been under review for the journal Hydrology and Earth System Sciences (HESS). The manuscript was not accepted for further review after discussion.

# Steady State Non-isothermal Well Flow in a Slanted Aquifer: Mathematical formulation and Field Application to a Deep Fault in the Xinzhou Geothermal Field in Guangdong, China

Guoping Lu and Bill X. Hu

Abstract. This paper develops a novel mathematical formulation for geothermal well flow. Non-isothermal flow would implicate the effectiveness of gravity as a body force term regulated by viscosity and density as well. Consequently it is a critical concept in practice that a dome-shaped water head surface would be present in its equilibrium-state water potential, as a proper observation needed to understand geothermal flow fields. Tabulation and formula are compiled on water density and viscosity as a function of temperatures and pressures to facilitate calculations. The derived formulas were applied to the field study site in a deep fault zone at a geothermal field in coastal Guangdong province, China, based on observations from a thousand-meter-depth borehole drilling project. The deep fault is unique in having a steep plane that emerges at the ground surface, and constitutes fast flow path for deep thermal water up to 115 °C and static water pressure up to 10 MPa at the borehole bottom. The fault is conceptualized as an inclined thin aquifer, and formula are derived for thermal outflows for the sloped aquifer to quantify the flow in the fault plane. Results showed that the deep fault has permeability equivalent to clean sands and lower end of unconsolidated gravels. Deep faults could provide useful information on pathways of preferential fluid flows. The deep fault study has several implications in deep geothermal environments and pressure characterizations, regional groundwater circulation limits, and pressure wave propagations in earthquake prediction in the deep crust.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Guoping Lu and Bill X. Hu

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
- Printer-friendly version - Supplement

Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
- Printer-friendly version - Supplement
Guoping Lu and Bill X. Hu
Guoping Lu and Bill X. Hu

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