St1 Deep Heat Oy First deep geothermal project in Scandinavia - PowerPoint PPT Presentation

St1 Deep Heat Oy First deep geothermal project in Scandinavia Achievements today Tero Saarno tero.saarno@st1.fi Tel. +358 50 373 1923 1 4/2/2019 St1 Deep Heat Oy

St1 Deep Heat project: plant concept • Concept is basically an 40 MW EGS (Enhanced Geothermal System) heat plant • This gives better efficiency for the plant and allows more electricity to be used in pumping • Finnish district heating networks are all designed with maximum temperature 120 °C and normal maximal operating temperature is around 115 °C. • Summer time minimum temperature is 75 °C • This causes the need to drill as far down as 6400 m in Southern Finland 2 4/2/2019 St1 Deep Heat Oy

Idea is not new Kellogg, Hager, Van der Hilst (Science, 1999) Installed capacity 2016 ( Source Stanford) • ~16 GWe • ~34 GWh Potential ( Source St1) • 0,1% of earth crust heat energy could produce all energy for all mankind for 10 000 years Mundus subterraneus - Athanasius Kircher (1601- 1680) 3 4/2/2019 St1 Deep Heat Oy

But there are many models Geothermal energy is: • Cost efficient • Reliable • Sustainable • Renewable • Environmentally friendly • Perfect base load solution to compensate other renewable energy sources natural fluctuations in networks 4 4/2/2019 St1 Deep Heat Oy

What has been done? Exploration well • Otaniemi site exploration drilling was done during summer 2015 with NQ2 coring drill. • Exploration well was ready 11.7.2015 at the MVD 1963 m and TD 2015 m 5 4/2/2019 St1 Deep Heat Oy

What has been done? Site and Drilling 6 4/2/2019 St1 Deep Heat Oy

What has been done? Seismic network 7 4/2/2019 St1 Deep Heat Oy

Traffic Light System 8 4/2/2019 St1 Deep Heat Oy

Traffic Light System 9 4/2/2019 St1 Deep Heat Oy

What has been done? Plant design 10 4/2/2019 St1 Deep Heat Oy

Project status • Both production wells have been drilled to more than half way down with air hammer (DTH drilling technique) • OTA-2 is 3,3km deep and OTA-3 6,4 km. • The deeper well was stimulated succesfully between June-July last summer with 18 600 m 3 of fresh water 11 4/2/2019 St1 Deep Heat Oy

What has been learned? How to stabilize a borehole more than 5km deep 12 4/2/2019 St1 Deep Heat Oy

What has been learned? How to create earthquakes big enough to see where the water goes BUT small enough not to disturb neighbors 15 4/2/2019 St1 Deep Heat Oy

What has been learned? Injecting huge amounts of fresh water to crystalline rock 16 4/2/2019 St1 Deep Heat Oy