Michael J Stephens
Michael J. Stephens is a Research Hydrologist with the USGS California Water Science Center, working in the Groundwater program area.
Michael's research focuses on water resources, particularly groundwater in sedimentary basins. He develops subsurface models of hydrogeologic systems including groundwater salinity, stratigraphy, porosity, temperature, and fault zones which help identify water resources.
Professional Experience
Research Hydrologist, USGS, 2022-present
Hydrologist, USGS, 2017-2022
Education and Certifications
MS, Geology, California State University, Sacramento, 2017
BS, Geology, University of Southern Indiana, 2015
Science and Products
Groundwater elevation data and models in and around select California oil fields (ver. 2.0, May 2024) Groundwater elevation data and models in and around select California oil fields (ver. 2.0, May 2024)
This data release contains groundwater elevation data and the associated model/code used to create groundwater elevation surfaces in and around select oil fields in California. The data and model provided here are intended to supplement interpretative manuscripts. Specific study areas will be added as Child Items found in this data release. Groundwater elevations are usually collected...
Idle well fluid measurements for oil and gas wells in California Idle well fluid measurements for oil and gas wells in California
This dataset consists of 119,494 lines of data consisting of idle well fluid level depth, auxiliary measurements, and well parameters from California oil and gas wells that were reported to the California Department of Conservation, Geologic Energy Management Division (CalGEM). The dataset was provided by CalGEM in March 2018 and includes measurements made from 1976 to 2018. There are 5...
Geological, geochemical, and geophysical data from the Lost Hills and Belridge oil fields Geological, geochemical, and geophysical data from the Lost Hills and Belridge oil fields
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed data for mapping groundwater salinity and characterizing aquifer systems in and near selected oil and gas fields in California. Data for the Lost Hills, North Belridge, and South Belridge oil fields include production and injection volumes, oil show data...
Geophysical and geological data for select petroleum wells in North Coles Levee Oil Field, Kern County, California Geophysical and geological data for select petroleum wells in North Coles Levee Oil Field, Kern County, California
This dataset includes geological and geophysical data from petroleum wells located in the North Coles Levee Oil Field, Kern County, California. The purpose of this dataset is to describe groundwater salinity trends and the related geological controls. These data are used in an interpretive manuscript that characterizes a salinity inversion (lower-salinities found below higher-salinities)...
Geophysical, geological, hydrological, and geochemical data for aquifer salinity mapping in the Elk Hills, Buena Vista, and Coles Levee Oil Fields, Kern County, California Geophysical, geological, hydrological, and geochemical data for aquifer salinity mapping in the Elk Hills, Buena Vista, and Coles Levee Oil Fields, Kern County, California
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (State Water Board) compiled and analyzed data for mapping groundwater salinity, characterizing aquifer systems, and documenting the effects of oil field water injection in the Elk Hills Elk Hills, Buena Vista, and Coles Levee Oil Fields, San Joaquin Valley, California. Data provided...
Geochemical, geological, and geophysical data for wells in the Poso Creek oil and gas field, Kern County, California Geochemical, geological, and geophysical data for wells in the Poso Creek oil and gas field, Kern County, California
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board and the U.S. Bureau of Land Management compiled and analyzed data for mapping groundwater salinity and characterizing aquifer systems in and around selected oil and gas fields in California. Data were collected for the Poso Creek oil field area which includes well construction data...
Mud logs from the Oxnard Oil Field, Ventura County, California Mud logs from the Oxnard Oil Field, Ventura County, California
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB) compiled and digitized mud logs from oil and gas wells in the Oxnard Oil Field area. Scanned copies of the mud logs were downloaded from the California Geologic Energy Management Division (CalGEM) online data and were digitized. Thirteen available mud logs associated with the...
Fluid levels in the Oxnard Oil Field, Ventura County, California Fluid levels in the Oxnard Oil Field, Ventura County, California
The U.S. Geological Survey (USGS), in cooperation with the California State Water Resources Control Board (SWRCB), compiled Fall 2017 fluid level elevation data from idle oil and gas wells in the Oxnard Oil Field to estimate vertical hydraulic head difference between oil production and overlying groundwater aquifer zones. Fluid elevations came from two sources, measurements in idle oil...
Geophysical and geochemical data for salinity mapping in the Midway-Sunset oil field area Geophysical and geochemical data for salinity mapping in the Midway-Sunset oil field area
The U.S. Geological Survey (USGS) and California State University-Sacramento, in cooperation with the California State Water Resources Control Board and U.S. Bureau of Land Management, compiled and analyzed data for mapping groundwater salinity in selected oil and gas fields in California. The data for the Midway-Sunset (MWSS) oil field includes digitized borehole geophysical data...
Geochemical and geophysical data for wells in the Fruitvale and Rosedale Ranch oil and gas fields, Kern County, California, USA Geochemical and geophysical data for wells in the Fruitvale and Rosedale Ranch oil and gas fields, Kern County, California, USA
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed data for the purpose of mapping groundwater salinity in selected oil and gas fields in California. The data for the Fruitvale and Rosedale Ranch oil fields include well construction data, digitized borehole geophysical data, geochemical analyses of water samples...
Filter Total Items: 15
Relations of groundwater quality to long-term surface disposal of produced water near the Midway-Sunset and Buena Vista Oil Fields, California, USA Relations of groundwater quality to long-term surface disposal of produced water near the Midway-Sunset and Buena Vista Oil Fields, California, USA
Contamination of groundwater by oil-field fluids in proximity to oil and gas development has been an issue of concern to water users and regulators given long histories of development and legacy disposal practices. A robust set of geochemical tracers including petroleum hydrocarbon compounds, thermogenic gases, inorganic ion concentrations, stable isotopes, radioactive isotopes, and...
Authors
Riley Gannon, Matthew K. Landon, Justin T. Kulongoski, Michael J. Stephens, Lyndsay B. Ball, John G. Warden, Tracy Davis, Janice M. Gillespie, Isabelle M. Cozzarelli
A joint Gaussian process model of geochemistry, geophysics, and temperature for groundwater TDS in the San Ardo Oil Field, California, USA A joint Gaussian process model of geochemistry, geophysics, and temperature for groundwater TDS in the San Ardo Oil Field, California, USA
Decline in availability of fresh groundwater has expanded interest in brackish groundwater resources; however, the distribution of brackish groundwater is poorly understood. Water resources in sedimentary basins across the United States often overlie oil and gas development. Mapping of groundwater total dissolved solids (TDS) using data from oil well geophysical logs has become an...
Authors
Michael J. Stephens, Will Chang, David H. Shimabukuro, Amanda Howery, Theron Sowers, Janice M. Gillespie
Assessing potential effects of oil and gas development activities on groundwater quality near and overlying the Elk Hills and North Coles Levee Oil Fields, San Joaquin Valley, California Assessing potential effects of oil and gas development activities on groundwater quality near and overlying the Elk Hills and North Coles Levee Oil Fields, San Joaquin Valley, California
Groundwater resources are utilized near areas of intensive oil and gas development in California’s San Joaquin Valley. In this study, we examined chemical and isotopic data to assess if thermogenic gas or saline water from oil producing formations have mixed with groundwater near the Elk Hills and North Coles Levee Oil Fields in the southwestern San Joaquin Valley. Major ion...
Authors
John G. Warden, Matthew K. Landon, Michael J. Stephens, Tracy Davis, Janice M. Gillespie, Peter B. McMahon, Justin T. Kulongoski, Andrew G. Hunt, David H. Shimabukuro, Riley Gannon, Lyndsay B. Ball
Land-use interactions, Oil-Field infrastructure, and natural processes control hydrocarbon and arsenic concentrations in groundwater, Poso Creek Oil Field, California, USA Land-use interactions, Oil-Field infrastructure, and natural processes control hydrocarbon and arsenic concentrations in groundwater, Poso Creek Oil Field, California, USA
Like many hydrocarbon production areas in the U.S., the Poso Creek Oil Field in California includes and is adjacent to other land uses (agricultural and other developed lands) that affect the hydrology and geochemistry of the aquifer overlying and adjacent to oil development. We hypothesize that the distributions of hydrocarbons and arsenic in groundwater in such areas will be controlled...
Authors
Peter B. McMahon, Matthew K. Landon, Michael J. Stephens, Kimberly A. Taylor, Michael Wright, Angela Hansen, Tamara E. C. Kraus, Isabelle M. Cozzarelli, David H. Shimabukuro, Theron A. Sowers, Justin T. Kulongoski, Andrew G. Hunt, Ruta Karolyte, Darren J. Hillegonds, Chris J. Ballentine
Fluid migration pathways to groundwater in mature oil fields: Exploring the roles of water injection/production and oil-well integrity in California, USA Fluid migration pathways to groundwater in mature oil fields: Exploring the roles of water injection/production and oil-well integrity in California, USA
Mature oil fields potentially contain multiple fluid migration pathways toward protected groundwater (total dissolved solids, TDS, in nonexempted aquifer
Authors
Peter B. McMahon, Matthew K. Landon, Michael J. Stephens, Kimberly A. Taylor, Janice M. Gillespie, Tracy Davis, David H. Shimabukuro
Multiple-well monitoring site within the Poso Creek Oil Field, Kern County, California Multiple-well monitoring site within the Poso Creek Oil Field, Kern County, California
IntroductionThe Poso Creek Oil Field is one of the many fields selected for regional groundwater mapping and monitoring by the California State Water Resources Control Board as part of the Oil and Gas Regional Monitoring Program (RMP; California State Water Resources Control Board, 2015, 2022b; U.S. Geological Survey, 2022a). The U.S. Geological Survey (USGS), in cooperation with the...
Authors
Rhett R. Everett, Peter B. McMahon, Michael J. Stephens, Janice M. Gillespie, Mackenzie M. Shepherd, Nicole C. Fenton
Geologic controls on groundwater salinity reversal in North Coles Levee Oil Field, southern San Joaquin Valley, California, USA Geologic controls on groundwater salinity reversal in North Coles Levee Oil Field, southern San Joaquin Valley, California, USA
This paper documents a reversal in the groundwater salinity depth gradient in the North Coles Levee Oil Field in the San Joaquin Valley, California. Salinity, measured in mg/L, was mapped with water quality data from groundwater and oil and gas wells and salinity estimated from oil and gas well borehole geophysical logs using Archie's equation. The resulting three-dimensional salinity...
Authors
Michael D Flowers, David H. Shimabukuro, Michael J. Stephens, John G. Warden, Janice M. Gillespie, Will Chang
Airborne electromagnetic survey results near the Poso Creek oil field, San Joaquin Valley, California, fall 2016 Airborne electromagnetic survey results near the Poso Creek oil field, San Joaquin Valley, California, fall 2016
An airborne electromagnetic survey west of the Poso Creek oil field, located in the southeastern San Joaquin Valley, California, was flown in October 2016 to improve understanding of the hydrogeologic setting and the distribution of groundwater salinity in the area. The airborne electromagnetic data were used to develop resistivity models of the subsurface, where the mean depth of...
Authors
Katrina D. Zamudio, Lyndsay B. Ball, Michael J. Stephens
Mapping aquifer salinity gradients and effects of oil field produced water disposal using geophysical logs: Elk Hills, Buena Vista and Coles Levee Oil Fields, San Joaquin Valley, California Mapping aquifer salinity gradients and effects of oil field produced water disposal using geophysical logs: Elk Hills, Buena Vista and Coles Levee Oil Fields, San Joaquin Valley, California
The effects of oil and gas production on adjacent groundwater quality are becoming a concern in many areas of the United States. As a result, it has become increasingly important to identify which aquifers require monitoring and protection. In this study, we map the extent of groundwater with less than 10,000 mg/L TDS both laterally and vertically near the Elk Hills, Buena Vista and...
Authors
Janice M. Gillespie, Michael J. Stephens, Will Chang, John G. Warden
Stratigraphic and structural controls on groundwater salinity variations in the Poso Creek Oil Field, Kern County, California, USA Stratigraphic and structural controls on groundwater salinity variations in the Poso Creek Oil Field, Kern County, California, USA
Groundwater total dissolved solids (TDS) distribution was mapped with a three-dimensional (3D) model, and it was found that TDS variability is largely controlled by stratigraphy and geologic structure. General TDS patterns in the San Joaquin Valley of California (USA) are attributed to predominantly connate water composition and large-scale recharge from the adjacent Sierra Nevada...
Authors
Michael J. Stephens, David H. Shimabukuro, Will Chang, Janice M. Gillespie, Zack Levinson
Groundwater quality of aquifers overlying the Oxnard Oil Field, Ventura County, California Groundwater quality of aquifers overlying the Oxnard Oil Field, Ventura County, California
Groundwater samples collected from irrigation, monitoring, and municipal supply wells near the Oxnard Oil Field were analyzed for chemical and isotopic tracers to evaluate if thermogenic gas or water from hydrocarbon-bearing formations have mixed with surrounding groundwater. New and historical data show no evidence of water from hydrocarbon-bearing formations in groundwater overlying...
Authors
Celia Z. Rosecrans, Matthew K. Landon, Katherine Marie Ransom, Janice M. Gillespie, Justin T. Kulongoski, Michael J. Stephens, Andrew G. Hunt, David H. Shimabukuro, Tracy Davis
A novel method for the extraction, purification and characterization of noble gases in produced fluids A novel method for the extraction, purification and characterization of noble gases in produced fluids
Hydrocarbon systems with declining or viscous oil production are often stimulated using enhanced oil recovery (EOR) techniques, such as the injection of water, steam and CO2, in order to increase oil and gas production. As EOR and other methods of enhancing production such as hydraulic fracturing have become more prevalent, environmental concerns about the impact of both new and...
Authors
Rebecca L. Tyne, Peter H Barry, D J Hillegonds, Andrew G. Hunt, Justin T. Kulongoski, Michael J. Stephens, D.J. Byrne, C. J. Ballentine
Science and Products
Groundwater elevation data and models in and around select California oil fields (ver. 2.0, May 2024) Groundwater elevation data and models in and around select California oil fields (ver. 2.0, May 2024)
This data release contains groundwater elevation data and the associated model/code used to create groundwater elevation surfaces in and around select oil fields in California. The data and model provided here are intended to supplement interpretative manuscripts. Specific study areas will be added as Child Items found in this data release. Groundwater elevations are usually collected...
Idle well fluid measurements for oil and gas wells in California Idle well fluid measurements for oil and gas wells in California
This dataset consists of 119,494 lines of data consisting of idle well fluid level depth, auxiliary measurements, and well parameters from California oil and gas wells that were reported to the California Department of Conservation, Geologic Energy Management Division (CalGEM). The dataset was provided by CalGEM in March 2018 and includes measurements made from 1976 to 2018. There are 5...
Geological, geochemical, and geophysical data from the Lost Hills and Belridge oil fields Geological, geochemical, and geophysical data from the Lost Hills and Belridge oil fields
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed data for mapping groundwater salinity and characterizing aquifer systems in and near selected oil and gas fields in California. Data for the Lost Hills, North Belridge, and South Belridge oil fields include production and injection volumes, oil show data...
Geophysical and geological data for select petroleum wells in North Coles Levee Oil Field, Kern County, California Geophysical and geological data for select petroleum wells in North Coles Levee Oil Field, Kern County, California
This dataset includes geological and geophysical data from petroleum wells located in the North Coles Levee Oil Field, Kern County, California. The purpose of this dataset is to describe groundwater salinity trends and the related geological controls. These data are used in an interpretive manuscript that characterizes a salinity inversion (lower-salinities found below higher-salinities)...
Geophysical, geological, hydrological, and geochemical data for aquifer salinity mapping in the Elk Hills, Buena Vista, and Coles Levee Oil Fields, Kern County, California Geophysical, geological, hydrological, and geochemical data for aquifer salinity mapping in the Elk Hills, Buena Vista, and Coles Levee Oil Fields, Kern County, California
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (State Water Board) compiled and analyzed data for mapping groundwater salinity, characterizing aquifer systems, and documenting the effects of oil field water injection in the Elk Hills Elk Hills, Buena Vista, and Coles Levee Oil Fields, San Joaquin Valley, California. Data provided...
Geochemical, geological, and geophysical data for wells in the Poso Creek oil and gas field, Kern County, California Geochemical, geological, and geophysical data for wells in the Poso Creek oil and gas field, Kern County, California
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board and the U.S. Bureau of Land Management compiled and analyzed data for mapping groundwater salinity and characterizing aquifer systems in and around selected oil and gas fields in California. Data were collected for the Poso Creek oil field area which includes well construction data...
Mud logs from the Oxnard Oil Field, Ventura County, California Mud logs from the Oxnard Oil Field, Ventura County, California
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB) compiled and digitized mud logs from oil and gas wells in the Oxnard Oil Field area. Scanned copies of the mud logs were downloaded from the California Geologic Energy Management Division (CalGEM) online data and were digitized. Thirteen available mud logs associated with the...
Fluid levels in the Oxnard Oil Field, Ventura County, California Fluid levels in the Oxnard Oil Field, Ventura County, California
The U.S. Geological Survey (USGS), in cooperation with the California State Water Resources Control Board (SWRCB), compiled Fall 2017 fluid level elevation data from idle oil and gas wells in the Oxnard Oil Field to estimate vertical hydraulic head difference between oil production and overlying groundwater aquifer zones. Fluid elevations came from two sources, measurements in idle oil...
Geophysical and geochemical data for salinity mapping in the Midway-Sunset oil field area Geophysical and geochemical data for salinity mapping in the Midway-Sunset oil field area
The U.S. Geological Survey (USGS) and California State University-Sacramento, in cooperation with the California State Water Resources Control Board and U.S. Bureau of Land Management, compiled and analyzed data for mapping groundwater salinity in selected oil and gas fields in California. The data for the Midway-Sunset (MWSS) oil field includes digitized borehole geophysical data...
Geochemical and geophysical data for wells in the Fruitvale and Rosedale Ranch oil and gas fields, Kern County, California, USA Geochemical and geophysical data for wells in the Fruitvale and Rosedale Ranch oil and gas fields, Kern County, California, USA
The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board compiled and analyzed data for the purpose of mapping groundwater salinity in selected oil and gas fields in California. The data for the Fruitvale and Rosedale Ranch oil fields include well construction data, digitized borehole geophysical data, geochemical analyses of water samples...
Filter Total Items: 15
Relations of groundwater quality to long-term surface disposal of produced water near the Midway-Sunset and Buena Vista Oil Fields, California, USA Relations of groundwater quality to long-term surface disposal of produced water near the Midway-Sunset and Buena Vista Oil Fields, California, USA
Contamination of groundwater by oil-field fluids in proximity to oil and gas development has been an issue of concern to water users and regulators given long histories of development and legacy disposal practices. A robust set of geochemical tracers including petroleum hydrocarbon compounds, thermogenic gases, inorganic ion concentrations, stable isotopes, radioactive isotopes, and...
Authors
Riley Gannon, Matthew K. Landon, Justin T. Kulongoski, Michael J. Stephens, Lyndsay B. Ball, John G. Warden, Tracy Davis, Janice M. Gillespie, Isabelle M. Cozzarelli
A joint Gaussian process model of geochemistry, geophysics, and temperature for groundwater TDS in the San Ardo Oil Field, California, USA A joint Gaussian process model of geochemistry, geophysics, and temperature for groundwater TDS in the San Ardo Oil Field, California, USA
Decline in availability of fresh groundwater has expanded interest in brackish groundwater resources; however, the distribution of brackish groundwater is poorly understood. Water resources in sedimentary basins across the United States often overlie oil and gas development. Mapping of groundwater total dissolved solids (TDS) using data from oil well geophysical logs has become an...
Authors
Michael J. Stephens, Will Chang, David H. Shimabukuro, Amanda Howery, Theron Sowers, Janice M. Gillespie
Assessing potential effects of oil and gas development activities on groundwater quality near and overlying the Elk Hills and North Coles Levee Oil Fields, San Joaquin Valley, California Assessing potential effects of oil and gas development activities on groundwater quality near and overlying the Elk Hills and North Coles Levee Oil Fields, San Joaquin Valley, California
Groundwater resources are utilized near areas of intensive oil and gas development in California’s San Joaquin Valley. In this study, we examined chemical and isotopic data to assess if thermogenic gas or saline water from oil producing formations have mixed with groundwater near the Elk Hills and North Coles Levee Oil Fields in the southwestern San Joaquin Valley. Major ion...
Authors
John G. Warden, Matthew K. Landon, Michael J. Stephens, Tracy Davis, Janice M. Gillespie, Peter B. McMahon, Justin T. Kulongoski, Andrew G. Hunt, David H. Shimabukuro, Riley Gannon, Lyndsay B. Ball
Land-use interactions, Oil-Field infrastructure, and natural processes control hydrocarbon and arsenic concentrations in groundwater, Poso Creek Oil Field, California, USA Land-use interactions, Oil-Field infrastructure, and natural processes control hydrocarbon and arsenic concentrations in groundwater, Poso Creek Oil Field, California, USA
Like many hydrocarbon production areas in the U.S., the Poso Creek Oil Field in California includes and is adjacent to other land uses (agricultural and other developed lands) that affect the hydrology and geochemistry of the aquifer overlying and adjacent to oil development. We hypothesize that the distributions of hydrocarbons and arsenic in groundwater in such areas will be controlled...
Authors
Peter B. McMahon, Matthew K. Landon, Michael J. Stephens, Kimberly A. Taylor, Michael Wright, Angela Hansen, Tamara E. C. Kraus, Isabelle M. Cozzarelli, David H. Shimabukuro, Theron A. Sowers, Justin T. Kulongoski, Andrew G. Hunt, Ruta Karolyte, Darren J. Hillegonds, Chris J. Ballentine
Fluid migration pathways to groundwater in mature oil fields: Exploring the roles of water injection/production and oil-well integrity in California, USA Fluid migration pathways to groundwater in mature oil fields: Exploring the roles of water injection/production and oil-well integrity in California, USA
Mature oil fields potentially contain multiple fluid migration pathways toward protected groundwater (total dissolved solids, TDS, in nonexempted aquifer
Authors
Peter B. McMahon, Matthew K. Landon, Michael J. Stephens, Kimberly A. Taylor, Janice M. Gillespie, Tracy Davis, David H. Shimabukuro
Multiple-well monitoring site within the Poso Creek Oil Field, Kern County, California Multiple-well monitoring site within the Poso Creek Oil Field, Kern County, California
IntroductionThe Poso Creek Oil Field is one of the many fields selected for regional groundwater mapping and monitoring by the California State Water Resources Control Board as part of the Oil and Gas Regional Monitoring Program (RMP; California State Water Resources Control Board, 2015, 2022b; U.S. Geological Survey, 2022a). The U.S. Geological Survey (USGS), in cooperation with the...
Authors
Rhett R. Everett, Peter B. McMahon, Michael J. Stephens, Janice M. Gillespie, Mackenzie M. Shepherd, Nicole C. Fenton
Geologic controls on groundwater salinity reversal in North Coles Levee Oil Field, southern San Joaquin Valley, California, USA Geologic controls on groundwater salinity reversal in North Coles Levee Oil Field, southern San Joaquin Valley, California, USA
This paper documents a reversal in the groundwater salinity depth gradient in the North Coles Levee Oil Field in the San Joaquin Valley, California. Salinity, measured in mg/L, was mapped with water quality data from groundwater and oil and gas wells and salinity estimated from oil and gas well borehole geophysical logs using Archie's equation. The resulting three-dimensional salinity...
Authors
Michael D Flowers, David H. Shimabukuro, Michael J. Stephens, John G. Warden, Janice M. Gillespie, Will Chang
Airborne electromagnetic survey results near the Poso Creek oil field, San Joaquin Valley, California, fall 2016 Airborne electromagnetic survey results near the Poso Creek oil field, San Joaquin Valley, California, fall 2016
An airborne electromagnetic survey west of the Poso Creek oil field, located in the southeastern San Joaquin Valley, California, was flown in October 2016 to improve understanding of the hydrogeologic setting and the distribution of groundwater salinity in the area. The airborne electromagnetic data were used to develop resistivity models of the subsurface, where the mean depth of...
Authors
Katrina D. Zamudio, Lyndsay B. Ball, Michael J. Stephens
Mapping aquifer salinity gradients and effects of oil field produced water disposal using geophysical logs: Elk Hills, Buena Vista and Coles Levee Oil Fields, San Joaquin Valley, California Mapping aquifer salinity gradients and effects of oil field produced water disposal using geophysical logs: Elk Hills, Buena Vista and Coles Levee Oil Fields, San Joaquin Valley, California
The effects of oil and gas production on adjacent groundwater quality are becoming a concern in many areas of the United States. As a result, it has become increasingly important to identify which aquifers require monitoring and protection. In this study, we map the extent of groundwater with less than 10,000 mg/L TDS both laterally and vertically near the Elk Hills, Buena Vista and...
Authors
Janice M. Gillespie, Michael J. Stephens, Will Chang, John G. Warden
Stratigraphic and structural controls on groundwater salinity variations in the Poso Creek Oil Field, Kern County, California, USA Stratigraphic and structural controls on groundwater salinity variations in the Poso Creek Oil Field, Kern County, California, USA
Groundwater total dissolved solids (TDS) distribution was mapped with a three-dimensional (3D) model, and it was found that TDS variability is largely controlled by stratigraphy and geologic structure. General TDS patterns in the San Joaquin Valley of California (USA) are attributed to predominantly connate water composition and large-scale recharge from the adjacent Sierra Nevada...
Authors
Michael J. Stephens, David H. Shimabukuro, Will Chang, Janice M. Gillespie, Zack Levinson
Groundwater quality of aquifers overlying the Oxnard Oil Field, Ventura County, California Groundwater quality of aquifers overlying the Oxnard Oil Field, Ventura County, California
Groundwater samples collected from irrigation, monitoring, and municipal supply wells near the Oxnard Oil Field were analyzed for chemical and isotopic tracers to evaluate if thermogenic gas or water from hydrocarbon-bearing formations have mixed with surrounding groundwater. New and historical data show no evidence of water from hydrocarbon-bearing formations in groundwater overlying...
Authors
Celia Z. Rosecrans, Matthew K. Landon, Katherine Marie Ransom, Janice M. Gillespie, Justin T. Kulongoski, Michael J. Stephens, Andrew G. Hunt, David H. Shimabukuro, Tracy Davis
A novel method for the extraction, purification and characterization of noble gases in produced fluids A novel method for the extraction, purification and characterization of noble gases in produced fluids
Hydrocarbon systems with declining or viscous oil production are often stimulated using enhanced oil recovery (EOR) techniques, such as the injection of water, steam and CO2, in order to increase oil and gas production. As EOR and other methods of enhancing production such as hydraulic fracturing have become more prevalent, environmental concerns about the impact of both new and...
Authors
Rebecca L. Tyne, Peter H Barry, D J Hillegonds, Andrew G. Hunt, Justin T. Kulongoski, Michael J. Stephens, D.J. Byrne, C. J. Ballentine