Heat flow density estimates in the Upper Rhine Graben using laboratory measurements of thermal conductivity on sedimentary rocks

Geothermal Energy

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Table 1 Mean calculated thermal conductivities λ and heat flow densities q for the various intervals in the GRT-1, GPK-1 and GPK-2 geothermal wells

Well	Interval	Mean T (°C)	∆T/∆z (°C/100 m)	Dry		Hot		Wet
Well	Interval	Mean T (°C)	∆T/∆z (°C/100 m)	Mean λ (W/mK)	Mean q (mW/m²)	Mean λ (W/mK)	Mean q (mW/m²)	Mean λ (W/mK)	Mean q (mW/m²)
GRT-1	Global	92.54	9.07	1.35 ± 0.20	122 ± 19	1.20 ± 0.18	109 ± 18	1.81 ± 0.19	164 ± 20
	Tertiary	71.59	9.32	1.25 ± 0.24	117 ± 24	1.20 ± 0.24	112 ± 24	1.71 ± 0.23	159 ± 24
	Jurassic	132.30	9.69	1.49 ± 0.04	144 ± 18	1.22 ± 0.05	118 ± 16	1.90 ± 0.05	184 ± 22
	Keuper	153.25	7.03	1.77 ± 0.07	125 ± 31	1.15 ± 0.07	81 ± 22	2.27 ± 0.08	160 ± 39
GPK-1	Global	64.49	10.13	1.40 ± 0.24	141 ± 26	1.25 ± 0.21	126 ± 23	1.85 ± 0.23	188 ± 26
	Tertiary	46.02	10.08	1.25 ± 0.30	126 ± 32	1.23 ± 0.30	124 ± 32	1.71 ± 0.29	172 ± 32
	Jurassic	83.07	12.46	1.50 ± 0.05	187 ± 22	1.32 ± 0.06	165 ± 21	1.91 ± 0.05	238 ± 25
	Keuper	101.54	8.37	1.85 ± 0.06	155 ± 24	1.22 ± 0.06	102 ± 17	2.32 ± 0.09	194 ± 31
GPK-2	Global	62.34	10.14	1.33 ± 0.26	135 ± 29	1.26 ± 0.25	127 ± 27	1.78 ± 0.25	181 ± 28
	Tertiary	49.00	9.78	1.25 ± 0.31	123 ± 33	1.23 ± 0.32	120 ± 33	1.71 ± 0.31	167 ± 33
	Jurassic	87.60	11.82	1.50 ± 0.05	177 ± 21	1.32 ± 0.06	157 ± 20	1.90 ± 0.05	225 ± 25
	Keuper	100.95	8.81	1.82 ± 0.10	160 ± 63	1.31 ± 0.07	115 ± 45	2.26 ± 0.12	199 ± 77

Mean measured temperatures and temperature gradients are given for the various intervals [global (from surface to top of the Muschelkalk), Tertiary, Jurassic and Keuper]. Data for dry rocks at ambient temperature (dry), dry rocks at in situ temperature (hot) and saturated rocks at ambient temperature (wet)