More information
Description
The main goal of this project is to evaluate the subsurface geothermal potential of the Baia Mare area, a region that has the highest values of heat flow recorded to date in RO. This assessment requires a multi-data and multi-disciplinary approach consisting in the evaluation of available data, the collection of modern geoscientific data, and in joint interpretation of this geo-data. The resulted 3D lithospheric, hydrogeological and geothermal models will be used further in geothermal energy exploitation, which will benefit the community from the Baia Mare area. Geothermal energy is a renewable source that has little effect on environment. The amount of CO2 emitted during the generation of electrical and thermal energy using this renewable source is very small, close to zero, since no burning process is involved. Our study area is located in the northwestern part of RO and comprises tens of villages and the town of Baia Mare. In the rural areas, wood is the main source used for space heating. As an effect, the measured quantities of CO2 emissions resulted from burning wood and fossil fuel are high. A wider range of geophysical data will be recorded and integrate it with a wealth of geological, hydrogeological, petrological and geochemical data in complex 3D geo-models. An added innovative aspect of the research will be given by customised algorithms for geophysical data processing and analysis. Cutting-edge techniques (joint probabilistic inversion of surface wave data, geoid, gravity anomalies and heat flow measurements) will be applied for the first time in this region and for the purpose of unveiling geothermal potential. The scientific outcomes and results of the project are represented by a multi-data comprehensive database, 3D geo-models, newly identified areas which are suitable for drilling of promising geothermal wells and increased knowledge on renewable energy, energy efficiency and security in the rural areas.
Summary of project results
Our project aimed to address two types of problems: a societal one and a scientific issue. The societal one was related to the high level of air and water pollution in a mining area located in the northwestern Romania and comprising tens of villages and the town of Baia Mare. For decades, this area was an important national source for Pb, Zn, Au, Ag, and Cu, but the mining activity transformed it into one of Romania’s most polluted with heavy metals mining area. One way to decrease the extreme pollution, in particular the CO2 emissions, is to find a source of green, renewable energy. Previous measurements showed high geothermal gradient and temperatures at depths greater than 3000 m. We performed a detailed study of the Baia Mare area and combined geological, geophysical, geochemical and hydrogeological available and new data for assessing its geothermal potential. This study also allowed our teams to gather data and model a region with high importance for understanding the geology of Carpathians and surroundings, but poorly covered by modern geophysical data. A dedicated website was developed which allows both researchers and the general public free access to the project’s activities and results (www.geysirbaiamare.ro).
In our project, we first performed a regional assessment of the geothermal potential using existent geological, hydrogeological, geochemical and geothermal data. We recorded active-source seismic data using explosive sources in order to identify and image possible reservoirs of thermal water into subsurface. The measurements were performed to south of the Baia Mare town along two lines with north-south and east-west orientations. Their total length was 33 km. The generation and recording of seismic waves was done by the University of Bucharest in collaboration with PROSPECTIUNI S.A. (Romania). The results provided the first information in the area about the subsurface geological structure and the presence of a system of deep faults considered paths for geothermal fluid transportation. Ambient seismic noise and magnetotelluric measurements were performed to identify water-bearing structures into subsurface. The magnetotelluric measurements were performed using equipment from the Lulea University of Technology (Sweden) in points spread over a larger area, between Sighetul Marmatiei and Targu Lapus, to north and to south of the Baia mare town. The researchers from the University of Oslo (Norway) and the Lulea University of Technology (Sweden) processed the data. The obtained resistivity sections imaged water-bearing layers and bodies of magmatic rocks.
The National Agency for Mineral Resources, Romania, is the main beneficiary of the scientific results of the project. The agency will use our results to select the open areas for geothermal water exploitation in the benefit of the local communities. The obtained seismic and resistivity sections provided us information about the geological structure and tectonic evolution of the sedimentary deposits of Neogene-Quaternary age, the fluid content and the location of intrusive bodies into the ground. Two locations for geothermal wells were proposed after the integrated analysis of the geological, hydrogeological, geophysical and geothermal data. The local community and the local public administration authorities will have the opportunity to use a cheap source for heating houses, official buildings or buildings with touristic activities. Thermal waters can also be used for greenhouse heating and spas.
Summary of bilateral results
The team from the University of Bucharest with less experience in the performing of magnetotelluric surveys had the opportunity to work together with the colleagues from Norway, gaining experience in this way. The integrated interpretation was done together and the final results are very interesting and useful for the people from the Baia Mare area. Private sector was involved in acquisition of this data, and the collaboration between the academia and private sector led to improvement in some of the workflows and efficiency in their respective institutes. The data analysis and interpretation is published in international journals accessible to geologists and engineers. The pre-print of the published articles will be available free of charge on dedicated servers like arxiv. The National Agency for Mineral Resources, Romania, the main beneficiary of these results, has the mandate to use this data and raise awareness about its availability, hence avoiding duplication of data collection. Our results will contribute to furthering the exploration with possibility of exploitation of geothermal energy, which is part of the national energy transition efforts.