Dissolved organic compounds in geothermal fluids used for energy production: a review

Geothermal Energy

Science – Society – Technology

Table 6 Overview of compiled data on organic matter in geothermal fluids from the Los Humeros (Mexico), Mutnovskii and Annenskii (Russia) geothermal fields

Well	Sample	Well depth (m)	Reservoir depth (m)	Discharge temperature (\(^{\circ }\hbox {C}\))	Reservoir temperature (\(^{\circ }\hbox {C}\))	Type of reservoir rock	Geological formation	No. of organic compounds	Range of n-alkanes	CPI
Los Humeros, Sánchez-Avila et al. (2021)			1150–2800		300–400\(^{\mathrm{a}}\)	Pre-caldera andesites	Neogene Quaternary	48 (6 homologues)
H-7	Condensate	2782		348					C10–C33	0.68
H-9	Condensate	2752		320					C10–C33	0.52
H-20	Condensate	2830		301					C10–C33	0.48
H-31	Condensate	1926		331					C10–C33	0.64
H-39	Condensate	2290		336					C11–C31	0.57
H-44	Condensate	1770		312					C10–C33	0.46
H-45	Condensate	2280		323					C10–C33	0.70
H-49	Condensate	2030		292					C11–C32	0.65
H-50	Condensate	2580		319					C10–C33	0.54
H-56	Condensate	1930		314					C10–C32	0.65
Mutnovskii, Kompanichenko et al. (2016)						Volcanic and volcano sedimentary	Oligocene Quaternary
4-E/Dachnyi	Condensate	1600	1600–2000	175	270			48 (9 homologues)	C10–C26	-
no. 3/Severo	Condensate	1800		97	300–310			22 (5 homologues)	C10–C18 C23–C28	-
Annenskii, Poturay (2017)						Volcanic and tuff sedimentary	Upper Cretacerous	72 (13 homologues)
Well 21	Water	202	2000–3000	54	99\(^{\mathrm{b}}\)				C10–C14 C17–C32	0.95
Well 2	Water	44	2000–3000	54	99\(^{\mathrm{b}}\)				C10–C14 C17–C35	0.9

\(^{\mathrm{a}}\) Based on calculations of stabilized temperatures by the sphere method adjusted by PPEP (pressure profile versus depth) method (Gutiérrez-Negrín et al. 2010).
\(^{\mathrm{b}}\) Estimated by quartz thermometer (Kulakov 2014).