Evaluation of deep geothermal exploration drillings in the crystalline basement of the Fennoscandian Shield Border Zone in south Sweden

Geothermal Energy

Science – Society – Technology

Table 4 Comparison of thermal data from the FFC-1 well with other deep boreholes drilled in the crystalline upper crust

	FFC-1	DGE-1^a	Gravberg-1^b	Bh32012 in Lake Vättern^c	Outokumpu R-2500^d	Hunt well, Western Canada^e
Depth, m	3133	3702	6957	1820	2516	2363
Temperature, °C	84	85	116	37	40	47
Q, mW/m²	51–66^f	58^f	50	35–47	40–45	51
Gradient, °C/km	7–24	22–24	14–18	15–20	14–17	20
K, W/(m K)	2.4–3.6	2.5–3.6	3.4	1.8–2.8	2.5–3.3	2.5
A, μW/m³	3.0^f	5.8^f	2.0–5.0	0.1^f	1.6–5.4	2.9–3.4
Dominating rock types	Gneiss, amphibolite	Gneiss, amphibolite	Granite	Diorite	Metasediments Pegmatitic granite, ultramafic rocks	Gneiss, granite, mylonite