Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy)

Abstract

In this study, the sustainability of low-temperature geothermal field exploitation in a carbonate reservoir near Mondragone (CE), Southern Italy, is analyzed. The Mondragone geothermal field has been extensively studied through the research project VIGOR (Valutazione del potenzIale Geotermico delle RegiOni della convergenza). From seismic, geo-electric, hydro-chemical and groundwater data, obtained through the experimental campaigns carried out, physiochemical features of the aquifers and characteristics of the reservoir have been determined. Within this project, a well-doublet open-loop district heating plant has been designed to feed two public schools in Mondragone town. The sustainability of this geothermal application is analyzed in this study. A new exploration well (about 300 m deep) is considered to obtain further stratigraphic and structural information about the reservoir. Using the derived hydrogeological model of the area, a numerical analysis of geothermal exploitation was carried out to assess the thermal perturbation of the reservoir and the sustainability of its exploitation. The effect of extraction and reinjection of fluids on the reservoir was evaluated for 60 years of the plant activity. The results are fundamental to develop a sustainable geothermal heat plant and represent a real case study for the exploitation of similar carbonate reservoir geothermal resources. Author Contributions: Conceptualization, M.I., N.M., and L.V.; Data curation, M.I. and A.C. (Alfonso Corniello); Formal analysis, S.D.F.; Funding acquisition, M.I., A.C. (Alberto Carotenuto), N.M., and L.V.; Methodology, S.D.F. and N.M.; Project administration, M.I., A.C. (Alberto Carotenuto) and N.M.; Writing-original draft, S.D.F.; Writing-review and editing, M.I., A.

Well-Doublets: A First-Order Assessment of Geothermal SedHeat Systems

“…Finally, we point out that in geothermal reservoirs that are dominated by flow in natural fractures, there is an important short-circuiting mechanism associated with thermal effects: maximum fracture aperture increase occurs in the fracture with the most flow, reinforcing the flow rate [73]. It remains unclear if this process can be somewhat suppressed by flow management and by thermal recharge [74]. Assessing the commercial viability of a geothermal SedHeat reservoir that involves the injection of cold water is and One may assume that in the stratigraphic disposition shown, the permeability of the lowermost sandstone is several times that of the central sandstone, which in turn is several times that of the upper sandstone (a permeability range for the sandstones might be from 1 D to 0.1 D).…”

New Trends in Enhanced, Hybrid and Integrated Geothermal Systems

“…we point out that in geothermal reservoirs that are dominated by flow in natural fractures, there is an important short-circuiting mechanism associated with thermal maximum fracture aperture increase occurs in the fracture with the most flow, the flow rate [73]. It remains unclear if this process can be somewhat suppressed by flow management and by thermal recharge [74]. Assessing the commercial viability of a geothermal SedHeat reservoir that involves the injection of cold water is and will remain a challenging task.…”

Numerical modeling as a tool for evaluating the renewability of geothermal resources: the case study of the Euganean Geothermal System (NE Italy)

“…Due to the concomitant interaction of several processes, the assessment of renewability can be very complex. In this regard, numerical simulations are a helpful tool to reproduce the physical, chemical, and mechanical processes affecting a geothermal system and to assess the impact of geological and hydrogeological settings on the magnitude of these processes (Blöcher et al, 2010 ; Franco & Vaccaro, 2014 ; Gunnarsson & Aradóttir, 2015 ; Iorio et al, 2020 ; Llanos et al, 2015 ; O’Sullivan et al, 2010 ; Pandey et al, 2018 ). The application of numerical modeling for this purpose is widely employed in the literature (e.g., Baiocchi et al, 2013 ; Borović et al, 2019 ; Dempsey et al, 2012 , 2015 ; McKenna & Blackwell, 2004 ; Montanari et al, 2017 ; O’Sullivan et al, 2001 ; Porras et al, 2007 ; Viaroli et al, 2019 ; Volpi et al, 2017 ; Wisian & Blackwell, 2004 ).…”