Title
Effects of pore water-rock reaction on heat extraction from the karst geothermal reservoirs: Based on the dual media model
Author
Ji, Jiayan (China University of Petroleum - Beijing)
Song, Xianzhi (China University of Petroleum - Beijing)
Yi, Junlin (China University of Petroleum - Beijing)
Song, G. (TU Delft Applied Geology)
Wang, Gaosheng (China University of Petroleum - Beijing)
Date
2024
Abstract
Fractures and caves are the main flow and storage channels for the karst geothermal reservoirs, and the water-rock reaction within them significantly affects the thermal performance. Most previous studies concentrated on the fractures, disregarding the impact of the pore water-rock reaction. The objective of this study is to explore the importance of pore water-rock reactions and identify the influence of various parameters when considering pore and fracture water-rock reactions. A 3D thermal-hydraulic-chemical coupling model considering dual media of pores and fractures was developed. The importance of pore water-rock reactions is demonstrated, and quantitatively characterize the effect of injection temperature (Tin), injection rate (Qin), injection concentration (cin), and ratio of the reaction-specific surface area between pore and fracture (Ap/Af) on the thermal performance. Results indicate that the pore water-rock reaction drastically affects the hydraulic conductivity and pressure difference, even leading to an opposite trend. The influence of water-rock reaction in pores on fracture deformation is regulated by Ap/Af, which augments with Ap/Af. The relative contribution of Ap/Af to production temperature, net thermal power, pressure difference, and hydraulic conductivity are 12.8%, 4.1%, 6.8%, and 13.7%, respectively. This study provides a significant guide for accurate production prediction and exploitation of karst-based geothermal reservoirs.
Subject
Fracture aperture
Karst-based thermal reserve
Pore structure
Thermal performance
Water-rock reaction
To reference this document use:
http://resolver.tudelft.nl/uuid:9fa09968-6b60-41d5-820e-7378758d0d47
DOI
https://doi.org/10.1016/j.energy.2024.130651
Embargo date
2024-08-08
ISSN
0360-5442
Source
Energy, 293
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2024 Jiayan Ji, Xianzhi Song, Junlin Yi, G. Song, Gaosheng Wang