Geoffrey S Ellis (Former Employee)
Science and Products
Filter Total Items: 81
Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019 Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 6.9 billion barrels of oil and 41.5 trillion cubic feet of natural gas in conventional and continuous accumulations in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations onshore and in State waters of the U.S. Gulf Coast region.
Authors
Janet K. Pitman, Stanley T. Paxton, Scott A. Kinney, Katherine J. Whidden, Seth S. Haines, Brian A. Varela, Tracey J. Mercier, Cheryl A. Woodall, Christopher J. Schenk, Heidi M. Leathers-Miller, Ofori N. Pearson, Lauri A. Burke, Phuong A. Le, Justin E. Birdwell, Nicholas J. Gianoutsos, Katherine L. French, Ronald M. Drake, Thomas M. Finn, Geoffrey S. Ellis, Stephanie B. Gaswirth, Kristen R. Marra, Marilyn E. Tennyson, Chilisa M. Shorten
Position-specific distribution of hydrogen isotopes in natural propane: Effects of thermal cracking, equilibration and biodegradation Position-specific distribution of hydrogen isotopes in natural propane: Effects of thermal cracking, equilibration and biodegradation
Intramolecular isotope distributions, including isotope clumping and position specific fractionation, can provide proxies for the formation temperature and formation and destruction pathways of molecules. In this study, we explore the position-specific hydrogen isotope distribution in propane. We analyzed propane samples from 10 different petroleum systems with high-resolution molecular...
Authors
Hao Xie, Camilo Ponton, Michael Formolo, Michael Lawson, Geoffrey S. Ellis, Michael Lewan, Alexandre A. Ferreira, Erica T. Morais, Andre D. Spigolon, Alex L. Sessions, John M. Eiler
Assessment of continuous oil and gas resources in the Ordovician Collingwood Formation and Utica Shale of the Michigan Basin Province, 2019 Assessment of continuous oil and gas resources in the Ordovician Collingwood Formation and Utica Shale of the Michigan Basin Province, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 290 milllion barrels of shale oil and 7.9 trillion cubic feet of shale gas in the Ordovician Collingwood-Utica Shale Total Petroleum System of the Michigan Basin Province.
Authors
Christopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Heidi M. Leathers-Miller, Thomas M. Finn, Phuong A. Le, Michael E. Brownfield, Kristen R. Marra, Geoffrey S. Ellis
Sulfur isotope composition of individual compounds in immature organic-rich rocks and possible geochemical implications Sulfur isotope composition of individual compounds in immature organic-rich rocks and possible geochemical implications
We applied compound-specific sulfur isotope analysis (CSSIA) to organic matter (OM) extracted from ancient and immature organic-rich rocks from the Cretaceous Ghareb (Shefela Basin locality, Israel) and Miocene Monterey (Naples Beach locality, California, USA) Formations. Large variations in the δ34S values of different organosulfur compounds (OSCs), that reach up to 28‰ and 36‰, were...
Authors
Lubna Shawar, Ward Said-Ahmad, Geoffrey S. Ellis, Alon Amrani
Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019 Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable continuous mean resources of 96.5 trillion cubic feet of gas in the Middle Devonian Marcellus Shale of the Appalachian Basin Province.
Authors
Debra K. Higley, Catherine B. Enomoto, Heidi M. Leathers-Miller, Geoffrey S. Ellis, Tracey J. Mercier, Christopher J. Schenk, Michael H. Trippi, Phuong A. Le, Michael E. Brownfield, Cheryl A. Woodall, Kristen R. Marra, Marilyn E. Tennyson
Assessment of continuous oil and gas resources in the niobrara interval of the Cody Shale, Bighorn Basin Province, Wyoming and Montana, 2019 Assessment of continuous oil and gas resources in the niobrara interval of the Cody Shale, Bighorn Basin Province, Wyoming and Montana, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 534 million barrels of oil and 939 billion cubic feet of gas in the Niobrara interval of the Cody Shale in the Bighorn Basin Province, Wyoming and Montana.
Authors
Thomas M. Finn, Christopher J. Schenk, Tracey J. Mercier, Marilyn E. Tennyson, Phuong A. Le, Michael E. Brownfield, Kristen R. Marra, Heidi M. Leathers-Miller, Ronald M. Drake, Cheryl A. Woodall, Janet K. Pitman, Geoffrey S. Ellis, Scott A. Kinney
Kinetics of elemental sulfur reduction by petroleum hydrocarbons and the implications for hydrocarbon thermal chemical alteration Kinetics of elemental sulfur reduction by petroleum hydrocarbons and the implications for hydrocarbon thermal chemical alteration
Although sulfur-containing compounds are known to play a significant role in the diagenic and catagenic processes that generate oil and gas, relatively little is known about the kinetics of reactions between elemental S and petroleum hydrocarbons. To investigate this subject, a series of closed-system pyrolysis experiments using paraffin, a low-sulfur oil, and a high-sulfur oil with and...
Authors
Geoffrey S. Ellis, Tongwei Zhang, Paul G. Kralert, Yongchun Tang
Experimental investigation of the role of rock fabric in gas generation and expulsion during thermal maturation: Anhydrous closed-system pyrolysis of a bitumen-rich Eagle Ford Shale Experimental investigation of the role of rock fabric in gas generation and expulsion during thermal maturation: Anhydrous closed-system pyrolysis of a bitumen-rich Eagle Ford Shale
Gold-tube pyrolysis experiments were conducted on miniature core plugs and powdered rock from a bitumen-rich sample of Eagle Ford Shale to investigate the role of rock fabric in gas generation and expulsion during thermal maturation. The samples were isothermally heated at 130, 300, 310, 333, 367, 400, and 425 °C for 72 h under a confining pressure of 68.0 MPa, corresponding to six...
Authors
Deyong Shao, Geoffrey S. Ellis, Yanfang Li, Tongwei Zhang
Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases
Multiply isotopically substituted molecules (‘clumped’ isotopologues) can be used as geothermometers because their proportions at isotopic equilibrium relative to a random distribution of isotopes amongst all isotopologues are functions of temperature. This has allowed measurements of clumped-isotope abundances to be used to constrain formation temperatures of several natural materials...
Authors
Yanhua Shuai, Peter M.J. Douglas, Shuichang Zhang, Daniel A. Stolper, Geoffrey S. Ellis, Michael Lawson, Michael Lewan, Michael Formolo, Jingkui Mi, Kun He, Guoyi Hu, John M. Eiler
Experimental investigation on thermochemical sulfate reduction in the presence of 1-pentanethiol at 200 and 250 °C: Implications for in situ TSR processes occurring in some MVT deposits Experimental investigation on thermochemical sulfate reduction in the presence of 1-pentanethiol at 200 and 250 °C: Implications for in situ TSR processes occurring in some MVT deposits
Organic sulfur compounds are ubiquitous in natural oil and gas fields and moderate-low temperature sulfide ore deposits. Previous studies have shown that organic sulfur compounds are important in enhancing the rates of thermochemical sulfate reduction (TSR) reactions, but the details of these reaction mechanisms remain unclear. In order to assess the extent of sulfate reduction in the...
Authors
Shunda Yuan, Geoffrey S. Ellis, I-Ming Chou, Robert Burruss
Position-specific 13C distributions within propane from experiments and natural gas samples Position-specific 13C distributions within propane from experiments and natural gas samples
Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, ‘bulk’ isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one...
Authors
Alison Piasecki, Alex L. Sessions, Michael Lawson, A.A. Ferreira, E. V. Santos Neto, Geoffrey S. Ellis, Michael Lewan, J.M. Eilers
East African weathering dynamics controlled by vegetation-climate feedbacks East African weathering dynamics controlled by vegetation-climate feedbacks
Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm that the detrital clays accumulating in...
Authors
Sarah J. Ivory, Michael M. McGlue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen
Science and Products
Filter Total Items: 81
Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019 Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 6.9 billion barrels of oil and 41.5 trillion cubic feet of natural gas in conventional and continuous accumulations in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations onshore and in State waters of the U.S. Gulf Coast region.
Authors
Janet K. Pitman, Stanley T. Paxton, Scott A. Kinney, Katherine J. Whidden, Seth S. Haines, Brian A. Varela, Tracey J. Mercier, Cheryl A. Woodall, Christopher J. Schenk, Heidi M. Leathers-Miller, Ofori N. Pearson, Lauri A. Burke, Phuong A. Le, Justin E. Birdwell, Nicholas J. Gianoutsos, Katherine L. French, Ronald M. Drake, Thomas M. Finn, Geoffrey S. Ellis, Stephanie B. Gaswirth, Kristen R. Marra, Marilyn E. Tennyson, Chilisa M. Shorten
Position-specific distribution of hydrogen isotopes in natural propane: Effects of thermal cracking, equilibration and biodegradation Position-specific distribution of hydrogen isotopes in natural propane: Effects of thermal cracking, equilibration and biodegradation
Intramolecular isotope distributions, including isotope clumping and position specific fractionation, can provide proxies for the formation temperature and formation and destruction pathways of molecules. In this study, we explore the position-specific hydrogen isotope distribution in propane. We analyzed propane samples from 10 different petroleum systems with high-resolution molecular...
Authors
Hao Xie, Camilo Ponton, Michael Formolo, Michael Lawson, Geoffrey S. Ellis, Michael Lewan, Alexandre A. Ferreira, Erica T. Morais, Andre D. Spigolon, Alex L. Sessions, John M. Eiler
Assessment of continuous oil and gas resources in the Ordovician Collingwood Formation and Utica Shale of the Michigan Basin Province, 2019 Assessment of continuous oil and gas resources in the Ordovician Collingwood Formation and Utica Shale of the Michigan Basin Province, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 290 milllion barrels of shale oil and 7.9 trillion cubic feet of shale gas in the Ordovician Collingwood-Utica Shale Total Petroleum System of the Michigan Basin Province.
Authors
Christopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Heidi M. Leathers-Miller, Thomas M. Finn, Phuong A. Le, Michael E. Brownfield, Kristen R. Marra, Geoffrey S. Ellis
Sulfur isotope composition of individual compounds in immature organic-rich rocks and possible geochemical implications Sulfur isotope composition of individual compounds in immature organic-rich rocks and possible geochemical implications
We applied compound-specific sulfur isotope analysis (CSSIA) to organic matter (OM) extracted from ancient and immature organic-rich rocks from the Cretaceous Ghareb (Shefela Basin locality, Israel) and Miocene Monterey (Naples Beach locality, California, USA) Formations. Large variations in the δ34S values of different organosulfur compounds (OSCs), that reach up to 28‰ and 36‰, were...
Authors
Lubna Shawar, Ward Said-Ahmad, Geoffrey S. Ellis, Alon Amrani
Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019 Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable continuous mean resources of 96.5 trillion cubic feet of gas in the Middle Devonian Marcellus Shale of the Appalachian Basin Province.
Authors
Debra K. Higley, Catherine B. Enomoto, Heidi M. Leathers-Miller, Geoffrey S. Ellis, Tracey J. Mercier, Christopher J. Schenk, Michael H. Trippi, Phuong A. Le, Michael E. Brownfield, Cheryl A. Woodall, Kristen R. Marra, Marilyn E. Tennyson
Assessment of continuous oil and gas resources in the niobrara interval of the Cody Shale, Bighorn Basin Province, Wyoming and Montana, 2019 Assessment of continuous oil and gas resources in the niobrara interval of the Cody Shale, Bighorn Basin Province, Wyoming and Montana, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 534 million barrels of oil and 939 billion cubic feet of gas in the Niobrara interval of the Cody Shale in the Bighorn Basin Province, Wyoming and Montana.
Authors
Thomas M. Finn, Christopher J. Schenk, Tracey J. Mercier, Marilyn E. Tennyson, Phuong A. Le, Michael E. Brownfield, Kristen R. Marra, Heidi M. Leathers-Miller, Ronald M. Drake, Cheryl A. Woodall, Janet K. Pitman, Geoffrey S. Ellis, Scott A. Kinney
Kinetics of elemental sulfur reduction by petroleum hydrocarbons and the implications for hydrocarbon thermal chemical alteration Kinetics of elemental sulfur reduction by petroleum hydrocarbons and the implications for hydrocarbon thermal chemical alteration
Although sulfur-containing compounds are known to play a significant role in the diagenic and catagenic processes that generate oil and gas, relatively little is known about the kinetics of reactions between elemental S and petroleum hydrocarbons. To investigate this subject, a series of closed-system pyrolysis experiments using paraffin, a low-sulfur oil, and a high-sulfur oil with and...
Authors
Geoffrey S. Ellis, Tongwei Zhang, Paul G. Kralert, Yongchun Tang
Experimental investigation of the role of rock fabric in gas generation and expulsion during thermal maturation: Anhydrous closed-system pyrolysis of a bitumen-rich Eagle Ford Shale Experimental investigation of the role of rock fabric in gas generation and expulsion during thermal maturation: Anhydrous closed-system pyrolysis of a bitumen-rich Eagle Ford Shale
Gold-tube pyrolysis experiments were conducted on miniature core plugs and powdered rock from a bitumen-rich sample of Eagle Ford Shale to investigate the role of rock fabric in gas generation and expulsion during thermal maturation. The samples were isothermally heated at 130, 300, 310, 333, 367, 400, and 425 °C for 72 h under a confining pressure of 68.0 MPa, corresponding to six...
Authors
Deyong Shao, Geoffrey S. Ellis, Yanfang Li, Tongwei Zhang
Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases
Multiply isotopically substituted molecules (‘clumped’ isotopologues) can be used as geothermometers because their proportions at isotopic equilibrium relative to a random distribution of isotopes amongst all isotopologues are functions of temperature. This has allowed measurements of clumped-isotope abundances to be used to constrain formation temperatures of several natural materials...
Authors
Yanhua Shuai, Peter M.J. Douglas, Shuichang Zhang, Daniel A. Stolper, Geoffrey S. Ellis, Michael Lawson, Michael Lewan, Michael Formolo, Jingkui Mi, Kun He, Guoyi Hu, John M. Eiler
Experimental investigation on thermochemical sulfate reduction in the presence of 1-pentanethiol at 200 and 250 °C: Implications for in situ TSR processes occurring in some MVT deposits Experimental investigation on thermochemical sulfate reduction in the presence of 1-pentanethiol at 200 and 250 °C: Implications for in situ TSR processes occurring in some MVT deposits
Organic sulfur compounds are ubiquitous in natural oil and gas fields and moderate-low temperature sulfide ore deposits. Previous studies have shown that organic sulfur compounds are important in enhancing the rates of thermochemical sulfate reduction (TSR) reactions, but the details of these reaction mechanisms remain unclear. In order to assess the extent of sulfate reduction in the...
Authors
Shunda Yuan, Geoffrey S. Ellis, I-Ming Chou, Robert Burruss
Position-specific 13C distributions within propane from experiments and natural gas samples Position-specific 13C distributions within propane from experiments and natural gas samples
Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, ‘bulk’ isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one...
Authors
Alison Piasecki, Alex L. Sessions, Michael Lawson, A.A. Ferreira, E. V. Santos Neto, Geoffrey S. Ellis, Michael Lewan, J.M. Eilers
East African weathering dynamics controlled by vegetation-climate feedbacks East African weathering dynamics controlled by vegetation-climate feedbacks
Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm that the detrital clays accumulating in...
Authors
Sarah J. Ivory, Michael M. McGlue, Geoffrey S. Ellis, Adam Boehlke, Anne-Marie Lézine, Annie Vincens, Andrew S. Cohen
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government