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Geothermal 3D model of the Camp Basin

Evaluation of available deep geothermal resources in the Mesozoic reservoirs of the Camp Basin

The ICGC generates 3D basic information about the nature and structure of the subsurface to contribute to the future challenges set out by climate change scenarios in terms of water supply and decarbonization. 

That is why, within the framework of the GeoEnergia project: Deep Geothermal Energy (GeoEnergia-GP), which aims to advance towards the quantification of basic energy resources available in Catalonia, the ICGC has been developed and published the 3D geothermal model of the Camp Basin.

This area is known for the existence of deep geothermal resources and is identified and classified in the document Deep Geothermal Resources in Catalonia (RGOPCat): synthesis of their potential (ICGC, 2022).  Two main types of potential reservoirs are recognized:

  • Reservoirs associated with hydrothermal anomalies related to fault zones on the margin of the basin (Camp Fault) such as the thermal anomaly located between Montbrió del Camp, Botarell, and Riudecanyes, where thermal waters are found at 80°C at only 100 m depth.
  • Deep sedimentary reservoirs associated with the Mesozoic aquifers in the central part of the Neogene extensional basin.

The 3D geothermal model of the Camp Basin presented here evaluates the amount of stored energy or deep geothermal potential [MJ/m3] of the deep sedimentary reservoirs associated with the Mesozoic aquifers in the central part of the basin by using the USGS volumetric method "Heat-In-Place" (HIP) in 3D and from a stochastic approach. Thus, the results are expressed with three probabilities of occurrence: 10% HIP (P10), 50% HIP (P50), and 90% HIP (P90).

The modeled reservoirs

The Camp Basin is part of a set of SW-NE oriented extensional basins in the Catalan Coastal Ranges. The basin has a geometry of a strongly inclined half-graben towards its NW margin, where it is bounded by the Camp Fault. Below the Neogene sedimentary filling of the basin, which reaches a maximum thickness of about 2500 m near the towns of Cambrils and Montbrió del Camp, lie the Mesozoic carbonate and sedimentary deposits, as well as the Paleozoic substrate or basement. 

For their favorable hydrogeological characteristics for exploitation, the following four potential reservoirs have been considered within the Mesozoic series: 

  • Jurassic Aquifer: Formed by dolomitic breccias, dolomites, and fractured and karstified limestones. 
  • Middle-Upper Triassic Aquifer or Upper Muschelkalk facies (M3)*: Composed of tabular to massive fractured dolomites and limestones.
  • Middle Triassic Aquifer or Lower Muschelkalk facies (M1)*: Constituted by fractured dolomites and marly limestones.
  • Lower-Middle Triassic Aquifer or Buntsandstein (B1)*: Formed by sandstones and conglomerates.

These materials were drilled in the deep oil research borehole Reus-1 (Echánove et al., 1976), reaching a depth of 2228 m, where temperatures of 49°C and 52 °C were measured at 762 and 2015 m depth, respectively. No information is available from the hydrocarbon wells carried out later: Reus-2 and Reus-3 (MITECO, 2016). The drilling of the Reus-1 borehole (Echánove et al., 1976) revealed the existence of a deep geothermal resource associated with the various reservoirs. 

(*) Terminology used in the 3D Geological Resources Viewer and associated documentation (specification document and explanatory technical report of the 3D geothermal model of the Camp Basin).
Geoindex - 3D Viewer of geological resources
3D Viewer of geological resources

Viewer user guide (PDF, catalan)

3D geothermal model of the Fossa del Camp

Specifications of the Geothermal 3D Model of the Fossa del Camp v1.0 (18.07.2923) (PDF, Catalan)

Metadata of the geothermal 3D model of the Fossa del Camp (Catalan)

Avaluació dels recursos geotèrmics profunds als reservoris mesozoics de la Fossa del Camp (Desembre 2023)

Informe tècnic TR-0001/23 (PDF; 6,7 MB)

Evaluation of deep geothermal resources in the Mesozoic reservoirs of the Fossa del Camp (December 2023)

Technical report TR-0001/23 (PDF; 6,6 MB)

Composition with geological map, facies photographs, geological section and lithological column from the Reus-1 survey

Geological map of the Camp Basin; outcrops of B1 facies (A), M1 facies (B), M3 facies (C), and landscape view of Jurassic carbonate rocks (D); geological cross-section of the subsurface of the Camp Basin and lithological column of the Reus-1 borehole (modified from Echánove et al., 1976).


Construction of the 3D geothermal model en 3D

The construction of the geological model has been developed following the following phases of work:

  • Integration of the available previous geological information to generate an initial 3D geological model of the study area using the 3DGeomodeller® software (version 4.0.8, by Intrepid Geophysics) to build the main lithological and structural surfaces and several geological cross-sections. 
  • Integration of gravimetric and magnetic data for the adjustment and validation of the 3D voxet geological model through geophysical data inversion. This phase, performed using the 3DGeomodeller® software (version 4.0.8, Intrepid Geophysics), consists of iteratively calculating the probability for each voxel cell to correspond to a given lithological unit based on the initially assigned petrophysical properties until achieving the best fit with the measured geophysical data. This stochastic procedure allows the validation of the geological model.
  • Building the 3D thermal model. The "Forward Model Temperature" module of the 3DGeomodeller® software has been used to build a conductive model under steady-state conditions inferring the subsurface temperature distribution validated with the previous point data available, setting a Dirichlet-type boundary condition ( 1st type) at the base of the model established at 7 km obtained from the lithospheric model of Catalonia published in the GeoIndex Deep Geothermal. To take into account the uncertainty analysis of the thermal parameters, the "Parameter Sweep - Heat resource uncertainty" algorithm was used.
  • Based on the adjusted 3D geological and thermal model in voxet format, the geothermal potential of each of the four identified reservoirs has been calculated using the 3DHIP-Calculator tool (Piris et al., 2020), an application developed with Matlab programming language and compiled for Windows that  allows the stochastic approach using the volumetric method or Heat In Place (HIP) (Muffler and Cataldi, 1977; Muffler, 1979) obtaining the distribution function of the available resource in 2D and 3D (in PJ/km2 or MJ/m3) for different probabilities (P10, P50, and P90).
  • Finally, the SKUA-GOCAD® software (version 21 Paradigm) has been used to obtain the complete 3D geological model, the stratigraphic and structural surfaces, and the equivalent voxet model.

 

Building of the 3D geological model for the calculation of the deep geothermal potential: integration, model prior and obtaining the most probable geological model after the inversion.

Building of the 3D geological model for the calculation of the deep geothermal potential: integration of available geological information, model prior to geophysical inversion model and obtaining the most probable geological model after the inversion.


Results and conclusions

The geothermal model, including lithological and structural surfaces, temperature distribution and the results of geothermal potential calculation for the four modeled reservoirs at different probabilities (P10, P50, and P90), can be queried and visualized in the ICGC Geoindex - 3D Viewer of geological resources.

  • Jurassic Aquifer: It is at a depth of up to 3300 m and has a vertical thickness of up to 800 m, and occasionally reaches 1270 m. The temperature at the top of the unit would reach 81ºC in the SW end of the modeled area. The stored energy values range from 0 to 183 PJ/km2, with two peaks located beneath the municipalities of Cambrils, Vinyols, Riudoms, and Reus in the south, and below the municipality of Valls in the north. 
    Map of the distribution of stored energy in the Jurassic aquifer (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 

    Map of the distribution of stored energy in the Jurassic aquifer (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 


  • Middle Triassic Aquifer or Upper Muschelkalk facies (M3): It is at a depth of up to 3665 m. The temperature at the top of the unit would reach 104 ºC, considering the temperature model generated with an average gradient of approximately 2.5 ºC/100 m at the point where this unit is located at the greatest depth. The stored energy values range from 0 to 65 PJ/km2, with two peaks located below the municipalities of Cambrils, Vinyols, Riudoms, and Reus in the south, and below the municipality of Valls in the north.  
    Map of the distribution of stored energy in the Middle Triassic Aquifer (M3) (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 

    Map of the distribution of stored energy in the Middle Triassic Aquifer (M3) (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 


  • Middle Triassic Aquifer or Lower Muschelkalk facies (M1): It is at a depth of up to 3900 m. The temperature at the top of the unit would reach 113 ºC, coinciding with the point where this unit is located at the greatest depth. The stored energy values range from 0 to 56 PJ/km2, with two peaks located below the municipalities of Cambrils, Vinyols, Riudoms, and Reus in the south, and below the municipality of Valls in the north. 
    Map of the distribution of stored energy in the Middle Triassic Aquifer (M1) (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values.

    Map of the distribution of stored energy in the Middle Triassic Aquifer (M1) (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 


  • The deepest aquifer of the Lower Triassic Buntsandstein (B1): it is located at a depth of up to 4350 m. The temperature at the top of the unit would reach 116 ºC. The values of stored energy vary between 0 and 90 PJ/km2 with two peaks located beneath the municipalities of Cambrils, Vinyols, Riudoms, and Reus in the south, and beneath the municipality of Valls in the north.
    Distribution map of stored energy in the Lower Triassic B1 aquifer (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 

    Distribution map of stored energy in the Lower Triassic B1 aquifer (PJ/km2) with a probability of occurrence of 50%, 3D view of the reservoir temperature distribution and distribution histogram of modeled reservoir temperature values. 


  • The area with the highest potential within the Fossa del Camp is in the southern half of the modelled area, where the different identified reservoirs reach their maximum values of stored energy (around 183 PJ/km2 for the Jurassic aquifer, 56-65 PJ/ km2 for the Middle Triassic aquifers and about 90 PJ/km2 for the Lower Triassic aquifer). 
  • In the northern half, approximately beneath the municipality of Valls, the potential is also high, but with lower maximum values of up to 68 PJ/km2 (around 68 PJ/km2  for the Jurassic aquifer, 9-30 PJ/km2 for the Middle Triassic aquifers, and about 31 PJ/m2 for the Lower Triassic aquifer).
  • The geothermal model and the potential calculation for each of the four identified reservoirs show how this resource could be distributed along the Fossa del Camp and the existence of significantly high geothermal potential in the southern half of the study area. In this sector, due to the deepening of the lithological units, the highest temperatures are achieved. This sector is located beneath the municipalities of Cambrils, Vinyols, Riudoms, and Reus.
  • The available resource in this sector could be exploited for direct thermal uses through doublet/triplet systems (exploitation well and injection wells) at depths depending on the target reservoir, both for industrial uses and/or urban district heating networks. Depending on the reservoir temperature, the use could be direct or supported by high-temperature industrial water-to-water heat pumps to meet the demand's needs.
  • The assessment of geothermal potential has an associated uncertainty due to the limited availability of initial data. Consequently, the results should be considered preliminary until research studies are promoted to minimize the risks associated with the exploitation of this resource.

Resources

Visualization and data format

 

References