The hydraulic tests and counter-stimulation were finalised during the week 21. The work progressed according to plan and almost in the planned schedule. A broken tool caused a few days’ delay.
The effects of the measures were closely monitored in co-operation with the Institute of Seismology of the University of Helsinki. A monitoring system has been set up for the project, which enabled hydraulic tests and stimulation to be carried out in a very controlled manner - without endangering people or property. A measurement network installed deep in the rock was used to monitor both the flow of water and the micro-earthquakes that the work steps caused deep in the bedrock. Micro-earthquakes may have caused momentary sounds on the ground in nearby areas. Sound waves could have also resonated in windows and structures, but they did not pose a danger to people or damage structures.
We apologize for any noise nuisance caused by micro-earthquakes that may have occurred to residents in nearby areas during the finishing phase of the heat wells.
Next, drilling equipment will be dismantled at the Otaniemi construction site and construction of above-ground parts will begin.
Further information:
St1 Oy, Matti Pentti, Director, Heat from the Ground, tel. +358 10 557 4119, matti.pentti@st1.fi
https://www.st1.com/geothermal-heat
St1 Nordic Oy is a Nordic energy Group whose vision is to be the leading producer and seller of CO2-aware energy. The Group researches and develops economically viable, environmentally sustainable energy solutions. St1 focuses on fuels marketing activities, oil refining and renewable energy solutions such as waste-based advanced ethanol fuels and industrial wind power. The Group has 1300 St1 and Shell branded retail stations in Finland, Sweden and Norway. Headquartered in Helsinki, St1 employs currently 770 people. www.st1.com