The operative agreement between the Italian Ministry of Economic Development (Directorate General for Nuclear Energy, Renewable Energy, and Energy Efficiency) and the Italian National Research Council (Department of Earth and Environment), signed in 2010, promoted a new project (VIGOR project) to evaluate the geothermal potential and the implementation of innovative use of geothermal resources in the so-called Regions of Convergence (i.e., Campania, Puglia, Calabria, and Sicilia). Within this context, a characterization of medium enthalpy geothermal resources have been carried out in the promising "Guardia dei Lombardi" area, located in the Campania region (Southern Italy, Province of Avellino). Intense subsurface hydrocarbon exploration has been carried out in the area over the last decades (particularly during the 1956-1996 period), providing large quantities of seismic and geochemical data. This exploration activity has demonstrated the presence of a fractured carbonate reservoir, that is constituted by the Cretaceous-Eocene sequence of the Apulian shallow water carbonate platform (e.g., SCROCCA, 2010 and reference therein). Following the Apennine orogenesis, the platform was deformed to shape a buried antiformal stack (NICOLAI & GAMBINI, 2007). In the study area the culmination of the uppermost thrust unit reaches a depth of about -250 m below the sea level (i.e. about 1125 m below the ground level). The reservoir fluids are mainly composed of CO2, which rests above an accumulation of brackish water in the central and upper part of the culmination of the deep carbonatic aquifer (e.g., Monte Forcuso 1 and 2 wells), and saline water along the flank of the buried anticline (e.g., Bonito 1 Dir, Ciccone 1 wells). In previous assessment mainly made by ENEL (1987; 1994), a reservoir fluid has been estimated in the area that reaches temperature of 120°C at the depth of 3000 m below ground level, associated to a heat flow of 90 mW/m2. (DELLA VEDOVA et alii, 2001). These parameters suggest the presence of a medium enthalpy geothermal resource. The presence of thermal waters in the area (Terme di San Teodoro) provides further constrain about the geochemical characteristics of the reservoir water.. Reservoir fluid temperature up to about 124°C were calculated using different geothermometers (DUCHI et alii, 1995). In this study, the overall structural-stratigraphic setting of the reservoir/caprock system has been defined on the basis of the integrated interpretation of a composite dataset of surface and subsurface geological, geophysical and geochemical information. In particular, thanks to the cooperation of ENI Company, we have had access to a wide dataset composed by seismic reflection profiles, well data, logs and cores. A careful assessment of temperature field at depth has been carried out analyzing the well logs through Horner plot construction (RIDER, 1996 and reference therein). Where the data were scarce, the approach proposed by DELLA VEDOVA, et alii (2001) has been applied. On the basis of well tests, cores analysis and mud losses/absorptions, it has been possible to re-estimate the reservoir properties, confirming quite good permeabilities for the fractured carbonate reservoir. One of the main results of this research is the development of an integrated 3D geological model which provides the base for a detailed assessment of the possible geothermal exploitation of the carbonate reservoir. The preliminary results of our analysis suggest that the "Guardia dei Lombardi" site could be indicated as an interesting area for the geothermal medium enthalpy exploitation, although the presence of the CO2 gas cap should be carefully
Characterization of medium enthalpy geothermal resource in the Campania region (Southern Apennines, Italy),within the framework of the VIGOR project:from geological data to resource modeling
SCROCCA D;PETRACCHINI L;LIVANI M;BRILLI M;BRANDANO M;
2012
Abstract
The operative agreement between the Italian Ministry of Economic Development (Directorate General for Nuclear Energy, Renewable Energy, and Energy Efficiency) and the Italian National Research Council (Department of Earth and Environment), signed in 2010, promoted a new project (VIGOR project) to evaluate the geothermal potential and the implementation of innovative use of geothermal resources in the so-called Regions of Convergence (i.e., Campania, Puglia, Calabria, and Sicilia). Within this context, a characterization of medium enthalpy geothermal resources have been carried out in the promising "Guardia dei Lombardi" area, located in the Campania region (Southern Italy, Province of Avellino). Intense subsurface hydrocarbon exploration has been carried out in the area over the last decades (particularly during the 1956-1996 period), providing large quantities of seismic and geochemical data. This exploration activity has demonstrated the presence of a fractured carbonate reservoir, that is constituted by the Cretaceous-Eocene sequence of the Apulian shallow water carbonate platform (e.g., SCROCCA, 2010 and reference therein). Following the Apennine orogenesis, the platform was deformed to shape a buried antiformal stack (NICOLAI & GAMBINI, 2007). In the study area the culmination of the uppermost thrust unit reaches a depth of about -250 m below the sea level (i.e. about 1125 m below the ground level). The reservoir fluids are mainly composed of CO2, which rests above an accumulation of brackish water in the central and upper part of the culmination of the deep carbonatic aquifer (e.g., Monte Forcuso 1 and 2 wells), and saline water along the flank of the buried anticline (e.g., Bonito 1 Dir, Ciccone 1 wells). In previous assessment mainly made by ENEL (1987; 1994), a reservoir fluid has been estimated in the area that reaches temperature of 120°C at the depth of 3000 m below ground level, associated to a heat flow of 90 mW/m2. (DELLA VEDOVA et alii, 2001). These parameters suggest the presence of a medium enthalpy geothermal resource. The presence of thermal waters in the area (Terme di San Teodoro) provides further constrain about the geochemical characteristics of the reservoir water.. Reservoir fluid temperature up to about 124°C were calculated using different geothermometers (DUCHI et alii, 1995). In this study, the overall structural-stratigraphic setting of the reservoir/caprock system has been defined on the basis of the integrated interpretation of a composite dataset of surface and subsurface geological, geophysical and geochemical information. In particular, thanks to the cooperation of ENI Company, we have had access to a wide dataset composed by seismic reflection profiles, well data, logs and cores. A careful assessment of temperature field at depth has been carried out analyzing the well logs through Horner plot construction (RIDER, 1996 and reference therein). Where the data were scarce, the approach proposed by DELLA VEDOVA, et alii (2001) has been applied. On the basis of well tests, cores analysis and mud losses/absorptions, it has been possible to re-estimate the reservoir properties, confirming quite good permeabilities for the fractured carbonate reservoir. One of the main results of this research is the development of an integrated 3D geological model which provides the base for a detailed assessment of the possible geothermal exploitation of the carbonate reservoir. The preliminary results of our analysis suggest that the "Guardia dei Lombardi" site could be indicated as an interesting area for the geothermal medium enthalpy exploitation, although the presence of the CO2 gas cap should be carefullyI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
