Background
To reduce CO2 emissions and to strengthen renewable energy sources HELEN Oy plans to drill a pilot well as deep single coaxial in well heat exchangers in the city of Helsinki. In combination with heat pumps, the well shall be used for heating purposes. Erdwerk has been assigned as a consultant to address a project scope of works including, but not limited to geological interpretation and risk analysis, drilling and well engineering.

Geology, Well Design and Drilling Program
The geology of Helsinki is largely dominated by metamorphic and magmatic rocks (granites, gneisses, and amphibolites). The geothermal heat flow is known to be relatively low, with a geothermal gradient of about 1.37 °C/100 m. The in well heat exchanger is planned to be drilled vertically to a maximum depth of about 2,500 m. The well will be drilled with an air system using pneumatic down-the-hole (air) hammer equipment. This technology is very common in the Scandinavian region and highly efficient in crystalline hard rock.

Further assistance
After completion of the drilling program, ERDWERK GmbH will continue to work with HELEN Oy in the tendering and drilling phase of the project.