New geophysical inversion and modeling tools developed by the PIXIL project have been applied to a conceptual model of the Garriga geothermal anomaly in Spain.
After two and a half years of research, the PIXIL (Pyrenees Imaging eXperience: an international network) project is coming to an end. PIXIL is today the first cross-border network (Spain-Andorra-France) for the characterization of the subsoil by “geophysical imagery” in the field of geothermal energy. The project was supported by five Spanish and French partners across different research areas – Universitat de Barcelona, Basque Center for Applied Mathematics (BCAM), Pôle Avenia, INRIA and RealTimeSeismic – and coordinated by the Barcelona Supercomputing Center.
We first reported on the PIXIL project in 2020, shortly after the project started. It was envisaged as a transnational and multidisciplinary scientific and technological cooperation that aims to develop the most advanced tools for analyzing the Earth’s subsoil, with particular emphasis on promoting the use of geothermal energy in the region. “The project was 65% co-financed by the European Regional Development Fund (ERDF) via the Interreg VA Spain-France-Andorra programme.
“The PIXIL project has succeeded in interconnecting the academic and industrial sectors dedicated to geothermal energy. For two and a half years, we have been able to refine technologies and demonstrate applications that would not have been possible otherwise. said Josep de la Puente, head of the geoscience applications group at the Barcelona Supercomputing Center and coordinator of PIXIL.
“In addition, through working sessions open to the geothermal community, we were able to address the issues of this technology with a great future in our region. We hope to have contributed our grain of sand so that geothermal energy is a complementary technology in the revolution towards clean energies of local origin”, added de la Puente.
Design of imaging algorithms for the characterization of geothermal reservoirs
PIXIL’s research in the field of imaging algorithm design has led to the development of a novel high-order parallel modeling tool for simulating 3D magnetotelluric (MT) geophysical experiments. Simultaneously, researchers developed deep neural networks (DNNs) aimed at solving the so-called inverse problem – how to determine subsurface properties from recorded measurements. These DNNs have also been applied to the design of better well logging instruments.
In addition, research was carried out in collaboration with the industrial partner of the PIXIL project, RealTimeSeismic, to build a tool based on Full Wave Inversion (FWI) adapted to surface waves. The goal is to apply it to data acquired by RealTimeSeismic during a near-surface seismic survey.
Implementation in supercomputers for the geothermal sector
Although the design of innovative algorithms is essential to the effectiveness of imaging technologies, it is their computational implementation that gives the concept applicability. Thus, PIXIL has also endeavored to implement the methodological advances developed and to transform them into fast, precise and reliable computer programs.
The result of this effort was the latest version of PETGEM, a parallel code that focuses on the detection and characterization of geothermal reservoirs (and other valuable resources) using high-performance computational and electromagnetic methods. Thanks to PIXIL’s research, PETGEM has proven to be a scalable, flexible, accurate and efficient software for solving realistic test cases in marine and terrestrial contexts. Additionally, PETGEM has been selected for the first Lab-to-Market (L2M) pre-assessment study of the R+D+I Energy for Society Network (XRE4S) in which the technology and the opportunities it offers are valued at market.
Applications of geothermal technologies
An essential aspect of the PIXIL project has been the ability to demonstrate the improvement of the technologies developed with real applications and experiments to quantify the results obtained. Specifically, a reference model such as the geothermal anomaly of La Garriga, located in the Catalan region of Vallés Oriental, has been studied and reinterpreted to renew the existing conceptual model.
Thus, the new conceptual model integrates geophysical results (obtained from electromagnetic, seismic, gravity and temperature data) with geochemical, geological and hydrogeological results. In this way, it was possible to deepen the mechanisms that control many geothermal systems present in the Pyrenees.
This case study served as inspiration for the models and tests of the new geophysical inversion tools generated within the framework of the PIXIL project. Moreover, a collection of models of increasing complexity, inspired by a geothermal reservoir controlled by default, has also been established to test some of the numerical tools developed by the project partners.
Source: PIXIL Project