Geoffrey S Ellis
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.
Geoffrey Ellis' 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.
Professional Experience
2006-Present: Research Geologist, Energy Resources Program, USGS
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, USGS
1988-1990: Geochemist, Northeast Research Institute
Education and Certifications
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
Affiliations and Memberships*
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
Member 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 Journal of Natural Gas Geoscience
Member of the editorial board of the journal Unconventional Resources
Science and Products
Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis
Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA
The modern muds of Laguna Mar Chiquita (Argentina): Particle size and geochemical trends from a large saline lake in the "thick-skinned" Andean foreland
Introduction to special section: China shale gas and shale oil plays
Organic sedimentation in modern lacustrine systems: A case study from Lake Malawi, East Africa
Qualitative and quantitative analysis of Dibenzofuran, Alkyldibenzofurans, and Benzo[b]naphthofurans in crude oils and source rock extracts
Lake formation, characteristics and evolution in retroarc deposystems: A synthesis of data from the modern Andean orogen and its associated basins
Vegetation controls on weathering intensity during the last deglacial transition in southeast Africa
Experimental investigation of changes in methane adsorption of bitumen-free Woodford Shale with thermal maturation induced by hydrous pyrolysis
Formation temperatures of thermogenic and biogenic methane
Compositional and stable carbon isotopic fractionation during non-autocatalytic thermochemical sulfate reduction by gaseous hydrocarbons
Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: molecular tracers for oil migration distances
Science and Products
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Filter Total Items: 67
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 sulfur source. At the end of each experiment, the S-isotopicAuthorsAlexander Meshoulam, Geoffrey S. Ellis, Ward Said Ahmad, Andrei Deev, Alex L. Sessions, Yongchun Tang, Jess F. Adkins, Jinzhong Liu, William P. Gilhooly, Zeev Aizenshtat, Alon AmraniCompound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA
Thiadiamondoids (TDs) are diamond-like compounds with a sulfide bond located within the cage structure. These compounds were suggested as a molecular proxy for the occurrence and extent of thermochemical sulfate reduction (TSR). Compound-specific sulfur-isotope analysis of TDs may create a multi-parameter system, based on molecular and δ34S values that may be sensitive over a wider range of TSR anAuthorsZvi Gvirtzman, Ward Said-Ahmad, Geoffrey S. Ellis, Ronald J. Hill, J. Michael Moldowan, Zhibin Wei, Alon AmraniThe modern muds of Laguna Mar Chiquita (Argentina): Particle size and geochemical trends from a large saline lake in the "thick-skinned" Andean foreland
Laguna Mar Chiquita (central Argentina; ~latitude 31°S, longitude 63°W) provides an outstanding opportunity to examine organic facies development and petroleum source-rock potential in a modern thick-skinned foreland basin lake. In this case study, we define profundal, paleodelta, and lake-margin depositional environments based on trends in bathymetry and lake-floor sediment particle size. SedimenAuthorsMichael M McGlue, Geoffrey S Ellis, Andrew S. CohenIntroduction to special section: China shale gas and shale oil plays
In the last 10 years, the success of shale gas and shale oil productions as a result of technological advances in horizontal drilling, hydraulic fracturing and nanoscale reservoir characterization have revolutionized the energy landscape in the United States. Resource assessment by the China Ministry of Land and Resources in 2010 and 2012 and by the U.S. Energy Information Administration in 2011 aAuthorsShu Jiang, Hongliu Zeng, Jinchuan Zhang, Neil Fishman, Baojun Bai, Xianming Xiao, Tongwei Zhang, Geoffrey S. Ellis, Xinjing Li, Bryony Richards-McClung, Dongsheng Cai, Yongsheng MaOrganic sedimentation in modern lacustrine systems: A case study from Lake Malawi, East Africa
This study examines the relationship between depositional environment and sedimentary organic geochemistry in Lake Malawi, East Africa, and evaluates the relative significance of the various processes that control sedimentary organic matter (OM) in lacustrine systems. Total organic carbon (TOC) concentrations in recent sediments from Lake Malawi range from 0.01 to 8.80 wt% and average 2.83 wt% forAuthorsGeoffrey S. Ellis, Barry J. Katz, Christopher A. Scholz, Peter K. SwartQualitative and quantitative analysis of Dibenzofuran, Alkyldibenzofurans, and Benzo[b]naphthofurans in crude oils and source rock extracts
Dibenzofuran (DBF), its alkylated homologues, and benzo[b]naphthofurans (BNFs) are common oxygen-heterocyclic aromatic compounds in crude oils and source rock extracts. A series of positional isomers of alkyldibenzofuran and benzo[b]naphthofuran were identified in mass chromatograms by comparison with internal standards and standard retention indices. The response factors of dibenzofuran in relatiAuthorsMeijun Li, Geoffrey S. EllisLake formation, characteristics and evolution in retroarc deposystems: A synthesis of data from the modern Andean orogen and its associated basins
Lake deposystems are commonly associated with retroarc mountain belts in the geological record. These deposystems are poorly characterized in modern retroarcs, placing limits on our ability to interpret environmental signals from ancient deposits. To address this problem, we have synthesized our existing knowledge about the distribution, morphometrics, and sedimentary geochemical characteristics oAuthorsAndrew S. Cohen, Michael M. McGlue, Geoffrey S. Ellis, Hiran Zani, Peter W. Swarzenski, Mario L. Assine, Aguinaldo SilvaVegetation controls on weathering intensity during the last deglacial transition in southeast Africa
Tropical climate is rapidly changing, but the effects of these changes on the geosphere are unknown, despite a likelihood of climatically-induced changes on weathering and erosion. The lack of long, continuous paleo-records prevents an examination of terrestrial responses to climate change with sufficient detail to answer questions about how systems behaved in the past and may alter in the future.AuthorsSarah J. Ivory, Michael M. McGlue, Geoffrey S. Ellis, Anne-Marie Lézine, Andrew S. Cohen, Annie VincensExperimental investigation of changes in methane adsorption of bitumen-free Woodford Shale with thermal maturation induced by hydrous pyrolysis
This study quantifies the effects of organic-matter (OM) thermal maturity on methane (CH4) sorption, on the basis of five samples that were artificially matured through hydrous pyrolysis achieved by heating samples of immature Woodford Shale under five different time–temperature conditions. CH4-sorption isotherms at 35 °C, 50 °C, and 65 °C, and pressures up to 14 MPa on dry, solvent-extracted sampAuthorsHaiyan Hu, Tongwei Zhang, Jaclyn D. Wiggins-Camacho, Geoffrey S. Ellis, Michael D. Lewan, Xiayong ZhangFormation temperatures of thermogenic and biogenic methane
Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a “clumped isotope” technique. Thermogenic gases yield formAuthorsD.A. Stolper, M. Lawson, C.L. Davis, A.A. Ferreira, E. V. Santos Neto, G.S. Ellis, M. D. Lewan, Anna M. Martini, Y. Tang, M. Schoell, A.L. Sessions, J.M. EilerCompositional and stable carbon isotopic fractionation during non-autocatalytic thermochemical sulfate reduction by gaseous hydrocarbons
The possibility of autocatalysis during thermochemical sulfate reduction (TSR) by gaseous hydrocarbons was investigated by examination of previously reported laboratory and field data. This reaction was found to be a kinetically controlled non-autocatalytic process, and the apparent lack of autocatalysis is thought to be due to the absence of the required intermediate species. Kinetic parameters fAuthorsXinyu Xia, Geoffrey S. Ellis, Qisheng Ma, Yongchun TangBenzo[b]naphthothiophenes and alkyl dibenzothiophenes: molecular tracers for oil migration distances
The secondary migration of petroleum is one of the most critical geological processes responsible for the accumulation of hydrocarbons in a sedimentary basin. Pyrrolic nitrogen compounds such as carbazoles and benzocarbazoles are thought to be practical molecular indicators for estimating relative migration distances of oil. In light oils or condensates, however, considerable analytical errors areAuthorsMeijun Li, T.-G. Wang, Shengbao Shi, Keyu Liu, Geoffrey S. Ellis - News
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