Geoffrey S Ellis
Biography
Geoffrey Ellis is a petroleum geochemist with the Energy Resources Program (ERP) of the US Geological Survey. He manages the sealed tube and hydrous pyrolysis laboratories within the Central Energy Resources Science Center. His research interests encompass the areas of organic-inorganic interactions in petroleum systems, gas isotope geochemistry, and the controls on sedimentary organic geochemistry in aquatic environments. He has published extensively on the process of thermochemical sulfate reduction and its impact on petroleum geochemistry. He is also actively investigating the application of compound-specific sulfur isotope analysis to problems in petroleum and organic geochemistry. He also has ongoing research projects involving clumped and position specific isotope analysis of hydrocarbons and organosulfur compounds and their relation to petroleum formation processes.
Further information about Dr. Ellis’ research products can be found here:
https://scholar.google.com/citations?user=qlXgLE8AAAAJ&hl=en&oi=ao
Education
Ph.D., Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science, University of Miami
M.S., Geochemistry, Colorado School of Mines
B.A., Geological Sciences, Cornell University
Profession Experience
2006-Present: Research Geologist, Energy Resources Program, U.S. Geological Survey
2003-2006: Postdoctoral Fellow, Division of Chemistry & Chemical Engineering, California Institute of Technology
1996-2003: Graduate Research Assistant, Rosenstiel School of Marine and Atmospheric Science, University of Miami
1994-1996: Consulting Petroleum Geochemist, Venezuela
1991-1994: Physical Scientist, Nation Research Program, Water Resources Division, U.S. Geological Survey
1988-1990: Geochemist, Northeast Research Institute
Affiliations
Affiliate faculty Department of Geology and Geological Engineering, Colorado School of Mines
Member American Association of Petroleum Geologists, European Association of Organic Geochemists, Geochemical Society, Geological Society of America, Association of Afro-Asian Petroleum Geochemists, Latin American Association of Organic Geochemistry
Member of the “Committee on Research” of the American Association of Petroleum Geologists (2009-present)
Vice-chairman of the executive council of the Association of Afro-Asian Petroleum Geochemists
Founding member of the editorial board of the journal Petroleum Research
Member of the editorial board of the English-language version of the journal Acta Petrolei Sinica
Member of the editorial board of the journal China Petroleum Exploration
Member of the editorial board of the journal Unconventional Resources
Science and Products
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.
Schenk, Christopher J.; Mercier, Tracey J.; Woodall, Cheryl A.; Leathers-Miller, Heidi M.; Finn, Thomas M.; Le, Phuong A.; Brownfield, Michael E.; Marra, Kristen R.; Ellis, Geoffrey S.
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.
Higley, Debra K.; Enomoto, Catherine E; Leathers-Miller, Heidi M.; Ellis, Geoffrey S.; Mercier, Tracey J.; Schenk, Christopher J.; Trippi, Michael H.; Le, Phuong A.; Brownfield, Michael E.; Woodall, Cheryl A.; Marra, Kristen R.; Tennyson, Marilyn E.
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.
Finn, Thomas M.; Schenk, Christopher J.; Mercier, Tracey J.; Tennyson, Marilyn E.; Le, Phuong A.; Brownfield, Michael E.; Marra, Kristen R.; Leathers-Miller, Heidi M.; Drake, Ronald M.; Woodall, Cheryl A.; Pitman, Janet K.; Ellis, Geoffrey S.; Kinney, Scott A.
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-...
Ellis, Geoffrey S.; Zhang, Tongwei; Kralert, Paul G.; Tang, Yongchun 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...
Shao, Deyong; Ellis, Geoffrey S.; Li, Yanfang; Zhang, Tongwei 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...
Shuai, Yanhua; Douglas, Peter M.J.; Zhang, Shuichang; Stolper, Daniel A.; Ellis, Geoffrey S.; Lawson, Michael; Lewan, Michael; Formolo, Michael; Mi, Jingkui; He, Kun; Hu, Guoyi; Eiler, John M. 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...
Piasecki, Alison; Sessions, Alex L.; Lawson, Michael; Ferreira, A.A.; Santos Neto, E. V.; Ellis, Geoffrey S.; Lewan, Michael; Eilers, J.M. 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...
Yuan, Shunda; Ellis, Geoffrey S.; Chou, I-Ming; Burruss, Robert 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...
Ivory, Sarah J.; McGlue, Michael M.; Ellis, Geoffrey S.; Boehlke, Adam; Lézine, Anne-Marie; Vincens, Annie; Cohen, Andrew S. Depositional environment and organic matter accumulation of Upper Ordovician–Lower Silurian marine shale in the Upper Yangtze Platform, South China
The main controlling factors of organic matter accumulation in the Upper Ordovician Wufeng–Lower Silurian Longmaxi Formations are complex and remain highly controversial. This study investigates the vertical variation of total organic carbon (TOC) content as well as major and trace element concentrations of four Ordovician–Silurian transition...
Li, Yangfang; Zhang, Tongwei; Ellis, Geoffrey S.; Shao, Deyong Effects of thermal maturation and thermochemical sulfate reduction on compound-specific sulfur isotopic compositions of organosulfur compounds in Phosphoria oils from the Bighorn Basin, USA
Compound-specific sulfur isotope analysis was applied to a suite of 18 crude oils generated from the Permian Phosphoria Formation in the Bighorn Basin, western USA. These oils were generated at various levels of thermal maturity and some experienced thermochemical sulfate reduction (TSR). This is the first study to examine the effects of thermal...
Ellis, Geoffrey S.; Said-Ahamed, Ward; Lillis, Paul G.; Shawar, Lubna; Amrani, Alon Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis
The sulfur isotopic fractionation associated with the formation of organic sulfur compounds (OSCs) during thermochemical sulfate reduction (TSR) was studied using gold-tube pyrolysis experiments to simulate TSR. The reactants used included n-hexadecane (n-C16) as a model organic compound with sulfate, sulfite, or elemental sulfur as the...
Meshoulam, Alexander; Ellis, Geoffrey S.; Ahmad, Ward Said ; Deev, Andrei; Sessions, Alex L.; Tang, Yongchun; Adkins, Jess F.; Liu, Jinzhong; Gilhooly, William P.; Aizenshtat, Zeev; Amrani, Alon
USGS Releases New Standards for Natural Gas
USGS now has the new standard for natural gas.