Geothermal Energy
There has been a worldwide rise of anxiety regarding the increasing emissions of air pollution and the global climate change
Renewable energies can help to make an important part of energy mix. Especially, geothermal resources can be a reliable, affordable, alternative source of energy, been a cleaner and greener alternative to fossil fuels like coal.
The level of sustainable production of a geothermal resource increases with exploration methods development. A thorough understanding of the geology of the project area and how it fits into the surrounding regional geological and tectonic setting is crucial to understanding a given geothermal system. The exploration phase of a geothermal project aims at locating geothermal reservoirs for possible exploitation and at selecting the best sites for drilling production wells.
Geothermal exploration projects have a significant amount of risk associated with uncertainties encountered in the discovery of the geothermal resource. The key element of any geothermal investment is the proper location of geothermal installation, which would guarantee the relevant hydrogeothermal parameters of the water intake. Seismic exploration is the most effective method for geothermal water surveying. It is focused on the most promising areas with the specific goal of understanding the permeability pathways that bring thermal fluids from their deep source to shallower parts of the system, where they can be economically exploited for geothermal power production. Geophysical surveys help constrain understanding of stratigraphy, structure and heat flow. Seismic methods rely on elastic waves which have different velocities when travelling through different rock types, and are refracted or reflected at discontinuities in or between formations. Seismic surveys give information on the density of the formations, the porosity and texture, boundaries and discontinuities and fluid-filled zones and thus even temperature.
An important advantage of the seismic survey is that they support the selection of an optimal location of geothermal investment and determination of the geometry of geothermal aquifer, including the significant reduction of estimation error of groundwater reservoir temperature.
Seismic is not the only method required for making a geothermal program being successful. During drilling when the well temperatures are highly disturbed by drilling fluid circulation and cold water injection in to the well, well logging measurements help to determine formation temperature and reservoir pressures as well as valuable information on the location of aquifers and their relative size.
