Chemical and isotopic fingerprinting techniques provide support for tracing the origin and evolut... more Chemical and isotopic fingerprinting techniques provide support for tracing the origin and evolution of formation waters taken during downhole and drill stem tests from exploration wells in Saudi Arabian oil and gas fields. Low molar Cl/Br ratios (85-93) and a δ 18 O reverse loop suggests an evaporative seawater origin for hypersaline water from the Upper Permian-Lower Triassic Khuff Formation. In contrast, formation water from the Upper Carboniferous-Lower Permian Unayzah Group shows a heterogeneous trend between low salinity/low δ 18 O freshwater and hypersaline/intermediate δ 18 O brine, the latter being a product of evaporated seawater. Unayzah water salinity increases linearly with depth at the rate of 77 to 98 mg/L per meter, allowing quantitative prediction of water resistivity (R w) at specific reservoir depths. The increase in Ca and depletion of Mg and HCO 3 with Unayzah depth suggests the impact of temperature-triggered ion exchange processes that alter the primary host rock and formation water composition.
Nitrate (NO3−) represents one of the major groundwater constituents with increasing distribution ... more Nitrate (NO3−) represents one of the major groundwater constituents with increasing distribution and concentration in the Kingdom of Saudi Arabia. This study aimed to determine potential sources of nitrate in the Early to Late Cretaceous Wasia aquifer system at the Al Kharj area (Central Saudi Arabia) by an integrative approach using groundwater geochemistry, nitrate isotopes (15N–NO3 and 18O–NO3), and tritium (3H) measurements. The lowest saline groundwater samples (TDS = 1400–2000 mg/L) from the peripheral zone were representative for pristine groundwater from the Wasia aquifer with nitrate concentrations below 20 mg/L and low 18O–NO3 ratios (8.7–20.6‰) but enriched 15N–NO3 values (up to 10.8‰). In contrast, 11 out of 34 analyzed water samples from irrigation wells and cattle watering wells exceeded the World Health Organization (WHO) drinking water guideline value for nitrate of 50 mg/L with maximum concentrations of up to 395 mg/L. Nitrate fertilizers and atmospheric deposition ...
Abstract Major and trace elements, noble gases, and stable (δD, δ18O) and cosmogenic (3H, 14C) is... more Abstract Major and trace elements, noble gases, and stable (δD, δ18O) and cosmogenic (3H, 14C) isotopes were measured from geothermal fluids in two adjacent geothermal areas in NW-Mexico, Las Tres Virgenes (LTV) and Cerro Prieto (CP). The goal is to trace the origin of reservoir fluids and to place paleoclimate and structural-volcanic constraints in the region. Measured 3He/4He (R) ratios normalized to the atmospheric value (Ra = 1.386 × 10−6) vary between 2.73 and 4.77 and are compatible with mixing between a mantle component varying between 42 and 77% of mantle helium and a crustal, radiogenic He component with contributions varying between 23% and 58%. Apparent U–Th/4He ages for CP fluids (0.7–7 Ma) suggest the presence of a sustained 4He flux from a granitic basement or from mixing with connate brines, deposited during the Colorado River delta formation (1.5–3 Ma). Radiogenic in situ 4He production age modeling at LTV, combined with the presence of radiogenic carbon (1.89 ± 0.11 pmC – 35.61 ± 0.28 pmC) and the absence of tritium strongly suggest the Quaternary infiltration of meteoric water into the LTV geothermal reservoir, ranging between 4 and 31 ka BP. The present geochemical heterogeneity of LTV fluids can be reconstructed by mixing Late Pleistocene – Early Holocene meteoric water (58–75%) with a fossil seawater component (25–42%), as evidenced by Br/Cl and stable isotope trends. CP geothermal water is composed of infiltrated Colorado River water with a minor impact by halite dissolution, whereas a vapor-dominated sample is composed of Colorado River water and vapor from deeper levels. δD values for the LTV meteoric end-member, which are 20‰–44‰ depleted with respect to present-day precipitation, as well as calculated annual paleotemperatures 6.9–13.6 °C lower than present average temperatures in Baja California point to the presence of humid and cooler climatic conditions in the Baja California peninsula during the final stage of the Last Glacial Pluvial period. Quaternary recharge of the LTV geothermal reservoir is related to elevated precipitation rates during cooler-humid climate intervals in the Late Pleistocene and Early Holocene. The probable replacement of connate water or pore fluids by infiltrating surface water might have been triggered by enhanced fracture and fault permeability through contemporaneous tectonic–volcanic activity in the Las Tres Virgenes region. Fast hydrothermal alteration processes caused a secondary, positive δ18O-shift from 4‰ to 6‰ for LTV and from 2‰ to 4‰ for CP geothermal fluids since the Late Glacial infiltration.
Numerous volcanoes, hot springs, fumaroles, and geothermal wells occur in the Pacific region of L... more Numerous volcanoes, hot springs, fumaroles, and geothermal wells occur in the Pacific region of Latin America. These systems are characterized by high As concentrations and other typical geothermal elements such as Li and B. This paper presents a review of the available data on As concentrations in geothermal systems and their surficial discharges and As data on volcanic gases of Latin America. Data for geothermal systems in Mexico, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Ecuador, Bolivia, and Chile are presented. Two sources of As can be recognized in the investigated sites: Arsenic partitioned into volcanic gases and emitted in plumes and fumaroles, and arsenic in rocks of volcanic edifices that are leached by groundwaters enriched in volcanic gases. Water containing the most elevated concentrations of As are mature Na-Cl fluids with relatively low sulfate content and As concentrations reaching up to 73.6 mg L⁻¹ (Los Humeros geothermal field in Mexico), but more commonly ranging from a few mg L⁻¹ to tens of mg L⁻¹. Fluids derived from Na-Cl enriched waters formed through evaporation and condensation at shallower depths have As levels of only a few μg L⁻¹. Mixing of Na-Cl waters with shallower meteoric waters results in low to intermediate As concentrations (up to a few mg L⁻¹). After the waters are discharged at the ground surface, As(III) oxidizes to As(V) and attenuation of As concentration can occur due to sorption and co-precipitation processes with iron minerals and organic matter present in sediments. Understanding the mechanisms of As enrichment in geothermal waters and their fate upon mixing with shallower groundwater and surface waters is important for the protection of water resources in Latin America.
The northern discharge areas of the Ahuachapán, and Chipilapa geothermal fields can be subdivided... more The northern discharge areas of the Ahuachapán, and Chipilapa geothermal fields can be subdivided into four different zones based on their structural position, and the isotopic and chemical composition of their waters. In general, the contribution of geothermal waters ...
Se comprobó el uso de los isótopos ambientales como un método útil para mejorar la eficiencia de ... more Se comprobó el uso de los isótopos ambientales como un método útil para mejorar la eficiencia de la explotación actual en yacimientos petroleros del Golfo de México. En general, los isótopos estables como deuterio, 18O, 13C, 37Cl, 87Sr y 34S, apoyan en cuestiones sobre el origen de las aguas, su calidad, la evolución geoquímica, procesos de recarga, interacción agua-roca, origen de la salinidad y procesos de contaminación, mientras que los isótopos radiactivos (Tritio, 14C, 36Cl y 129I) proporcionan información sobre el tiempo de circulación, el origen y la edad de las aguas subterráneas. Desde el año 1998, la Gerencia de Geotermia del Instituto de Investigaciones Eléctricas está realizando proyectos de investigación en los campos petroleros de los activos de Producción Luna, Pol-Chuc, Chilapilla-Colomo (todos en el estado de Tabasco) y Cactus-Sitio Grande (Chiapas) en la Región Sur de Pemex Exploración y Producción (PEP). Como objetivo principal de dichos estudios se desarrollaron ...
espanolComo parte de la solucion del problema que representa la escasa informacion que se tiene a... more espanolComo parte de la solucion del problema que representa la escasa informacion que se tiene acerca del origen de la recarga profunda del yacimiento geotermico Los Azufres, Michoacan, se analizo el potencial de infiltracion y almacenamiento de la zona, a partir del estudio del escurrimiento superficial medido al fin de la temporada de secas. El papel que juega la composicion litologica de la region, se manifiesta directamente en los volumenes de agua detectados en los acuiferos del interior de cada unidad geologica; esto permitio hacer una clasificacion de sus condiciones hidrogeologicas: Complejo Basal Andesitico (reservorio principal del yacimiento), con un potencial de infiltracion variable, debido a heterogeneidades en su fracturamiento y alteracion hidrotermal; riolitas Agua Fria, con un potencial de infiltracion restringido a fracturas; domos San Andres y Cerro Mozo, formaciones impermeables y sin posibilidades de infiltracion; riolitas Yerbabuena con los domos El Bosque y ...
Hydrological balance calculations suggested a potential, average annual infiltration rate of 446 ... more Hydrological balance calculations suggested a potential, average annual infiltration rate of 446 mm/m for the Los Azufres area, which corresponds to a total of 82.2 million m per year. Due to the highly fractured and faulted structure of the volcanic underground, a considerable potential for the infiltration of meteoric water into deeper sections of the volcanic formations can be assumed. Isotopic data indicate the minor importance of recent meteoric water for the recharge of the geothermal reservoir. Very negative δC values can be explained by the input of organic carbon from the surface, but the lack of C in the deep fluids reflects a pre-historic age for the infiltration event. The dilution of the meteoric water by C-free CO2 gas from a shallow magma chamber complicates the exact age determination of the infiltration event, which probably occurred during Late Pleistocene or Early Holocene glacial periods. Additionally, the positive δD and δO trend of the geothermal brines towards...
The Las Tres Virgenes (LTV) geothermal reservoir is a liquid-dominated resource located in the Ba... more The Las Tres Virgenes (LTV) geothermal reservoir is a liquid-dominated resource located in the Baja California Peninsula (NW-Mexico) with a currently installed power capacity of 10 MWe. The sustainability of future electricity production at the LTV geothermal field raises concerns about the origin and hydraulic dynamics of exploited geothermal fluids. As part of the present study, water samples were taken from the production wells LTV-4 and LTV-11 with a maximum bottom depth of 2,413 m and 1,974 m, respectively, to analyze a series of chemical (major and trace elements) and isotopic ( 2 H, 3 H, 11 B, 13 C, 14 C, 18 O, 87 Sr/ 86 Sr) parameters. The chemical and isotopic composition of LTV geothermal fluids is compared with surface water types (precipitation, thermal springs, shallow groundwater, seawater) and host rocks from the Baja California region to define their primary provenance, as well as type and degree of hydrothermal alteration. Interpreted results are compared with data ...
The Water Rock Interaction (WRI) working group of the International Association of GeoChemistry (... more The Water Rock Interaction (WRI) working group of the International Association of GeoChemistry (IAGC) organizes the International Symposium on Water Rock Interaction on a triennial schedule. Since 1974, in settings varying from Park City (USA) to Vladivostock (Russia), these meetings have focused on scientific researchabout processes where the interaction of rocks, water in its many forms, gases, life, and human perturbation occur. These symposia bring together scientists, engineers, professionals, and students from around the world that represent almost all the Earth science disciplines, including geology, geochemistry, petroleum geology, ore deposits, environmental sciences and hazard geology.
En el proceso de desalacion del petroleo crudo se generan aguas residuales (aguas congenitas). Es... more En el proceso de desalacion del petroleo crudo se generan aguas residuales (aguas congenitas). Estas aguas pueden ser utilizadas en los pozos de inyeccion al subsuelo, sustituyendo el agua de primer uso requerida en la recuperacion secundaria de los yacimientos. Para lograr esta reutilizacion, se necesita aplicar un tratamiento a las aguas residuales. El objetivo de este estudio fue definir y desarrollar el mejor sistema de tratamiento de las aguas congenitas que permite obtener un efluente con la calidad adecuada para su aprovechamiento en los pozos de inyeccion. La caracterizacion del agua congenita indico un alto contenido de cloruros y de sodio, asi como una dureza extremadamente alta (4,500-4,800 mg/L). Ademas, el agua contiene bicarbonatos, sulfuros e hidrocarburos (DQO de 2,500-2,900 mg/L). El estudio de tratabilidad se realizo en dos etapas: pruebas en laboratorio y simulacion fisica de trenes en planta piloto. En laboratorio se estudio la factibilidad de diferentes procesos...
Chemical and isotopic fingerprinting techniques provide support for tracing the origin and evolut... more Chemical and isotopic fingerprinting techniques provide support for tracing the origin and evolution of formation waters taken during downhole and drill stem tests from exploration wells in Saudi Arabian oil and gas fields. Low molar Cl/Br ratios (85-93) and a δ 18 O reverse loop suggests an evaporative seawater origin for hypersaline water from the Upper Permian-Lower Triassic Khuff Formation. In contrast, formation water from the Upper Carboniferous-Lower Permian Unayzah Group shows a heterogeneous trend between low salinity/low δ 18 O freshwater and hypersaline/intermediate δ 18 O brine, the latter being a product of evaporated seawater. Unayzah water salinity increases linearly with depth at the rate of 77 to 98 mg/L per meter, allowing quantitative prediction of water resistivity (R w) at specific reservoir depths. The increase in Ca and depletion of Mg and HCO 3 with Unayzah depth suggests the impact of temperature-triggered ion exchange processes that alter the primary host rock and formation water composition.
Nitrate (NO3−) represents one of the major groundwater constituents with increasing distribution ... more Nitrate (NO3−) represents one of the major groundwater constituents with increasing distribution and concentration in the Kingdom of Saudi Arabia. This study aimed to determine potential sources of nitrate in the Early to Late Cretaceous Wasia aquifer system at the Al Kharj area (Central Saudi Arabia) by an integrative approach using groundwater geochemistry, nitrate isotopes (15N–NO3 and 18O–NO3), and tritium (3H) measurements. The lowest saline groundwater samples (TDS = 1400–2000 mg/L) from the peripheral zone were representative for pristine groundwater from the Wasia aquifer with nitrate concentrations below 20 mg/L and low 18O–NO3 ratios (8.7–20.6‰) but enriched 15N–NO3 values (up to 10.8‰). In contrast, 11 out of 34 analyzed water samples from irrigation wells and cattle watering wells exceeded the World Health Organization (WHO) drinking water guideline value for nitrate of 50 mg/L with maximum concentrations of up to 395 mg/L. Nitrate fertilizers and atmospheric deposition ...
Abstract Major and trace elements, noble gases, and stable (δD, δ18O) and cosmogenic (3H, 14C) is... more Abstract Major and trace elements, noble gases, and stable (δD, δ18O) and cosmogenic (3H, 14C) isotopes were measured from geothermal fluids in two adjacent geothermal areas in NW-Mexico, Las Tres Virgenes (LTV) and Cerro Prieto (CP). The goal is to trace the origin of reservoir fluids and to place paleoclimate and structural-volcanic constraints in the region. Measured 3He/4He (R) ratios normalized to the atmospheric value (Ra = 1.386 × 10−6) vary between 2.73 and 4.77 and are compatible with mixing between a mantle component varying between 42 and 77% of mantle helium and a crustal, radiogenic He component with contributions varying between 23% and 58%. Apparent U–Th/4He ages for CP fluids (0.7–7 Ma) suggest the presence of a sustained 4He flux from a granitic basement or from mixing with connate brines, deposited during the Colorado River delta formation (1.5–3 Ma). Radiogenic in situ 4He production age modeling at LTV, combined with the presence of radiogenic carbon (1.89 ± 0.11 pmC – 35.61 ± 0.28 pmC) and the absence of tritium strongly suggest the Quaternary infiltration of meteoric water into the LTV geothermal reservoir, ranging between 4 and 31 ka BP. The present geochemical heterogeneity of LTV fluids can be reconstructed by mixing Late Pleistocene – Early Holocene meteoric water (58–75%) with a fossil seawater component (25–42%), as evidenced by Br/Cl and stable isotope trends. CP geothermal water is composed of infiltrated Colorado River water with a minor impact by halite dissolution, whereas a vapor-dominated sample is composed of Colorado River water and vapor from deeper levels. δD values for the LTV meteoric end-member, which are 20‰–44‰ depleted with respect to present-day precipitation, as well as calculated annual paleotemperatures 6.9–13.6 °C lower than present average temperatures in Baja California point to the presence of humid and cooler climatic conditions in the Baja California peninsula during the final stage of the Last Glacial Pluvial period. Quaternary recharge of the LTV geothermal reservoir is related to elevated precipitation rates during cooler-humid climate intervals in the Late Pleistocene and Early Holocene. The probable replacement of connate water or pore fluids by infiltrating surface water might have been triggered by enhanced fracture and fault permeability through contemporaneous tectonic–volcanic activity in the Las Tres Virgenes region. Fast hydrothermal alteration processes caused a secondary, positive δ18O-shift from 4‰ to 6‰ for LTV and from 2‰ to 4‰ for CP geothermal fluids since the Late Glacial infiltration.
Numerous volcanoes, hot springs, fumaroles, and geothermal wells occur in the Pacific region of L... more Numerous volcanoes, hot springs, fumaroles, and geothermal wells occur in the Pacific region of Latin America. These systems are characterized by high As concentrations and other typical geothermal elements such as Li and B. This paper presents a review of the available data on As concentrations in geothermal systems and their surficial discharges and As data on volcanic gases of Latin America. Data for geothermal systems in Mexico, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Ecuador, Bolivia, and Chile are presented. Two sources of As can be recognized in the investigated sites: Arsenic partitioned into volcanic gases and emitted in plumes and fumaroles, and arsenic in rocks of volcanic edifices that are leached by groundwaters enriched in volcanic gases. Water containing the most elevated concentrations of As are mature Na-Cl fluids with relatively low sulfate content and As concentrations reaching up to 73.6 mg L⁻¹ (Los Humeros geothermal field in Mexico), but more commonly ranging from a few mg L⁻¹ to tens of mg L⁻¹. Fluids derived from Na-Cl enriched waters formed through evaporation and condensation at shallower depths have As levels of only a few μg L⁻¹. Mixing of Na-Cl waters with shallower meteoric waters results in low to intermediate As concentrations (up to a few mg L⁻¹). After the waters are discharged at the ground surface, As(III) oxidizes to As(V) and attenuation of As concentration can occur due to sorption and co-precipitation processes with iron minerals and organic matter present in sediments. Understanding the mechanisms of As enrichment in geothermal waters and their fate upon mixing with shallower groundwater and surface waters is important for the protection of water resources in Latin America.
The northern discharge areas of the Ahuachapán, and Chipilapa geothermal fields can be subdivided... more The northern discharge areas of the Ahuachapán, and Chipilapa geothermal fields can be subdivided into four different zones based on their structural position, and the isotopic and chemical composition of their waters. In general, the contribution of geothermal waters ...
Se comprobó el uso de los isótopos ambientales como un método útil para mejorar la eficiencia de ... more Se comprobó el uso de los isótopos ambientales como un método útil para mejorar la eficiencia de la explotación actual en yacimientos petroleros del Golfo de México. En general, los isótopos estables como deuterio, 18O, 13C, 37Cl, 87Sr y 34S, apoyan en cuestiones sobre el origen de las aguas, su calidad, la evolución geoquímica, procesos de recarga, interacción agua-roca, origen de la salinidad y procesos de contaminación, mientras que los isótopos radiactivos (Tritio, 14C, 36Cl y 129I) proporcionan información sobre el tiempo de circulación, el origen y la edad de las aguas subterráneas. Desde el año 1998, la Gerencia de Geotermia del Instituto de Investigaciones Eléctricas está realizando proyectos de investigación en los campos petroleros de los activos de Producción Luna, Pol-Chuc, Chilapilla-Colomo (todos en el estado de Tabasco) y Cactus-Sitio Grande (Chiapas) en la Región Sur de Pemex Exploración y Producción (PEP). Como objetivo principal de dichos estudios se desarrollaron ...
espanolComo parte de la solucion del problema que representa la escasa informacion que se tiene a... more espanolComo parte de la solucion del problema que representa la escasa informacion que se tiene acerca del origen de la recarga profunda del yacimiento geotermico Los Azufres, Michoacan, se analizo el potencial de infiltracion y almacenamiento de la zona, a partir del estudio del escurrimiento superficial medido al fin de la temporada de secas. El papel que juega la composicion litologica de la region, se manifiesta directamente en los volumenes de agua detectados en los acuiferos del interior de cada unidad geologica; esto permitio hacer una clasificacion de sus condiciones hidrogeologicas: Complejo Basal Andesitico (reservorio principal del yacimiento), con un potencial de infiltracion variable, debido a heterogeneidades en su fracturamiento y alteracion hidrotermal; riolitas Agua Fria, con un potencial de infiltracion restringido a fracturas; domos San Andres y Cerro Mozo, formaciones impermeables y sin posibilidades de infiltracion; riolitas Yerbabuena con los domos El Bosque y ...
Hydrological balance calculations suggested a potential, average annual infiltration rate of 446 ... more Hydrological balance calculations suggested a potential, average annual infiltration rate of 446 mm/m for the Los Azufres area, which corresponds to a total of 82.2 million m per year. Due to the highly fractured and faulted structure of the volcanic underground, a considerable potential for the infiltration of meteoric water into deeper sections of the volcanic formations can be assumed. Isotopic data indicate the minor importance of recent meteoric water for the recharge of the geothermal reservoir. Very negative δC values can be explained by the input of organic carbon from the surface, but the lack of C in the deep fluids reflects a pre-historic age for the infiltration event. The dilution of the meteoric water by C-free CO2 gas from a shallow magma chamber complicates the exact age determination of the infiltration event, which probably occurred during Late Pleistocene or Early Holocene glacial periods. Additionally, the positive δD and δO trend of the geothermal brines towards...
The Las Tres Virgenes (LTV) geothermal reservoir is a liquid-dominated resource located in the Ba... more The Las Tres Virgenes (LTV) geothermal reservoir is a liquid-dominated resource located in the Baja California Peninsula (NW-Mexico) with a currently installed power capacity of 10 MWe. The sustainability of future electricity production at the LTV geothermal field raises concerns about the origin and hydraulic dynamics of exploited geothermal fluids. As part of the present study, water samples were taken from the production wells LTV-4 and LTV-11 with a maximum bottom depth of 2,413 m and 1,974 m, respectively, to analyze a series of chemical (major and trace elements) and isotopic ( 2 H, 3 H, 11 B, 13 C, 14 C, 18 O, 87 Sr/ 86 Sr) parameters. The chemical and isotopic composition of LTV geothermal fluids is compared with surface water types (precipitation, thermal springs, shallow groundwater, seawater) and host rocks from the Baja California region to define their primary provenance, as well as type and degree of hydrothermal alteration. Interpreted results are compared with data ...
The Water Rock Interaction (WRI) working group of the International Association of GeoChemistry (... more The Water Rock Interaction (WRI) working group of the International Association of GeoChemistry (IAGC) organizes the International Symposium on Water Rock Interaction on a triennial schedule. Since 1974, in settings varying from Park City (USA) to Vladivostock (Russia), these meetings have focused on scientific researchabout processes where the interaction of rocks, water in its many forms, gases, life, and human perturbation occur. These symposia bring together scientists, engineers, professionals, and students from around the world that represent almost all the Earth science disciplines, including geology, geochemistry, petroleum geology, ore deposits, environmental sciences and hazard geology.
En el proceso de desalacion del petroleo crudo se generan aguas residuales (aguas congenitas). Es... more En el proceso de desalacion del petroleo crudo se generan aguas residuales (aguas congenitas). Estas aguas pueden ser utilizadas en los pozos de inyeccion al subsuelo, sustituyendo el agua de primer uso requerida en la recuperacion secundaria de los yacimientos. Para lograr esta reutilizacion, se necesita aplicar un tratamiento a las aguas residuales. El objetivo de este estudio fue definir y desarrollar el mejor sistema de tratamiento de las aguas congenitas que permite obtener un efluente con la calidad adecuada para su aprovechamiento en los pozos de inyeccion. La caracterizacion del agua congenita indico un alto contenido de cloruros y de sodio, asi como una dureza extremadamente alta (4,500-4,800 mg/L). Ademas, el agua contiene bicarbonatos, sulfuros e hidrocarburos (DQO de 2,500-2,900 mg/L). El estudio de tratabilidad se realizo en dos etapas: pruebas en laboratorio y simulacion fisica de trenes en planta piloto. En laboratorio se estudio la factibilidad de diferentes procesos...
Uploads
Papers by Peter Birkle