Characterisation of the fracture- and karst-controlled geothermal reservoir below Munich from geophysical wireline and well information

Geothermal Energy

Science – Society – Technology

Table 8 Summary of the interpreted HAZs of the reservoir with according fracture system characteristics (only open and partial fractures are considered), amount of karstified reservoir sections, and porosity taken from the 3D porosity model of Wadas and von Hartmann (2022)

HAZ	Identified by			Well	Fracture intensity [n m⁻¹]			Aperture [norm.]	IQ [%]		Strike direction	Karst [%]			Porosity model [%]
HAZ	RPS	ML	T	Well	Mean	Max	n	Mean	IF	BQ	Strike direction	M	V	F	Min	Max	Mean
1	x			5	1.2	12.6	97.1	0.28	3	71	E–W	1	1	1	4.4	10.0	8.2
	x		x	4	2.5	7.0	40.5	0.43	4	27	NW–SE to NE–SW	0	16	0	11.8	11.9	11.9
	x		x	1	1.2	14.2	35.2	0.33	7	15	NE–SE	16	3	26	12.3	13.4	12.8
	x			6	2.7	13.5	92.0	0.33	6	49	NW–SE	0	0	0	5.4	9.6	7.6
2		x		3	No data	No data	No data	No data	No data	No data	No data	No data	No data	No data	7.1	10.4	8.5
		x		5	0.0	1.4	1.4	0	0	6	No data	12	9	0	7.3	11.9	9.2
	x			6	0.3	5.2	38.6	0.29	2	0	NW–SE	1	0	0	6.9	9.1	8.1
		x		2a	0.3	5.0	24.9	0.32	0	35	N–S	4	11	0	3.3	9.2	6.4
3			x	4	0.7	2.4	10.2	0.37	16	13	NNE–SSW	13	0	0	5.3	6.7	6.0
4			x	4	0.4	2.5	7.3	0.52	47	0	NNW–SSE	0	0	10	0.1	9.0	0.7
5			x	4	2.2	8.8	47.5	0.28	36	2	N–S	0	5	0	5.6	6.7	5.7
6	x			1	1.2	8.6	223	0.37	36	5	N–S	2	15	1	0.4	9.0	4.1
7		x		1	0.6	3.6	9.4	0.35	0	50	N–S	7	0	0	0.5	5.9	1.3
8		x		1	0.4	5.6	45.5	0.39	0	13	N–S, NE–SW	3	1	0	4.6	10.5	9.6
9		x		2a	0.1	1.4	1.4	0.36	0	5	NW–SE	0	0	0	8.7	8.9	8.9
10		x		2a	0.4	3.9	15.0	0.29	8	12	N–S, NE–SW	0	30	11	2.1	4.3	2.9

The fracture intensity is corrected after Terzaghi (1965)
HAZ hydraulic active zone, RPS revolutions per second—flowmeter, ML mud loss, T temperature, IQ image quality, IF intensely fractured zone, BQ bad quality zone, M massive karst, V vuggy karst, F karst associated with fractures