Injection-Triggered Occlusion of Flow Pathways in Geothermal Operations

Table 1

Historical and recently hydrochemical composition of water sampled in 2016 at different locations at the Klaipeda geothermal site, see Figure 1 (Wolfgramm 2008 and 2010, unpublished reports by GTN Neubrandenburg). Italic numbers are years.

Sample		KGDP-2P		KGDP-1I			KGDP-4I
Well type		Production well since 1997		Injection well since 1997			Injection well since 1998
Location		Before filter	Before filter	Before filter	Before filter	After filter	Before filter	Before filter	After filter
Sample date		July 2001	March 2016	1997	March 2016	April 2016	1998	April 2016	April 2016
pH	—	6.3	6.55	5.9	6.63	6.63	6.2	6.54	6.49
Electrical conductivity	(μS/cm)	134,134	125,300	129,920	130,900	129,500	137,808	130,200	129,400
Total dissolved solids (TDS)	(mg/l)	95,810	89,801	92,800	93,814	92,811	98,434	93,312	92,739
T	(°C)	37.8	36.4	17.6 (2001)	10.1	12.7	17.2 (2001)	11.7	13.3
Redox	(mV)	48	−133	−6 (2001)	−94	−56.2	−9 (2001)	−4.2	−45.5
O2	(mg/l)	0.1 (2010)	0.45		0.11	2.3	0.1 (2010)	0.55	0.38
HCO3		55	85.4	112	85.4	85.4	52	85.4	91.5
F		0.25 (2010)	0.38		0.37	0.35	0.2 (2010)	0.34	0.36
Cl		58,400	56498.4	56,000	56009.9	54253.5	61,250	54899.3	53568.1
Br			355.9		333.6	347		353.7	363
NO3			<0.6		<0.6	<0.6	<1 (2010)	<0.6	<0.6
SO4		1830	1733.1	1910	1735.5	1742.4	1756	1707.7	1650.5
Na		25,000	24,299	24,550	24,249	24,022	25,150	24,481	24,225
K		600	616	611	621	619	915	607	620
Ca		7600	7558	6820	7500	7532	9100	7484	7506
Mg		2250	2375	2140	2344	2359	2700 (1999)	2355	2358
Fe		14	17	14 (2001)	18	18	14 (2001)	18	18
Mn		0.82	1	0.82 (2001)	1	1	0.82 (2001)	1	1
Li		4.53 (2010)	3.4		3.7	3.5	4.41 (2010)	3.4	3.3
B		10.4 (2010)	9.3		9.8	9.6	10.1 (2010)	9.3	9.1
Si		6.3 (2010)	4.7		4.9	4.9	6.3 (2010)	4.7	4.7
Sr		140	165	145	167	167	145 (1999)	163	167
Ba			0.19		0.2	0.19	0.21 (2010)	0.19	0.18
Al		0.017 (2010)	0.019 (2015)				0.018 (2010)