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Your search keyword '"ELLIS, GEOFFREY S."' showing total 135 results
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135 results on '"ELLIS, GEOFFREY S."'

3. Recognition of Artificial Gases Formed during Drill-Bit Metamorphism Using Advanced Mud Gas.

Author

Leon, Janaina Andrade de Lima, Penteado, Henrique Luiz de Barros, Ellis, Geoffrey S., Milkov, Alexei, and Filho, João Graciano Mendonça

Subjects
LIQUID-liquid interfaces, CARBONATE rocks, PROPERTIES of fluids, OIL wells, DRILLING fluids
Abstract

Drill-bit metamorphism (DBM) is the process of thermal degradation of drilling fluid at the interface of the bit and rock due to the overheating of the bit. The heat generated by the drill when drilling into a rock formation promotes the generation of artificial hydrocarbon and non-hydrocarbon gas, changing the composition of the gas. The objective of this work is to recognize and evaluate artificial gases originating from DBM in wells targeting oil accumulations in pre-salt carbonates in the Santos Basin, Brazil. For the evaluation, chromatographic data from advanced mud gas equipment, drilling parameters, drill type, and lithology were used. The molar concentrations of gases and gas ratios (especially ethene/ethene+ethane and dryness) were analyzed, which identified the occurrence of DBM. DBM is most severe when wells penetrate igneous and carbonate rocks with diamond-impregnated drill bits. The rate of penetration, weight on bit, and rotation per minute were evaluated together with gas data but did not present good correlations to assist in identifying DBM. The depth intervals over which artificial gases formed during DBM are recognized should not be used to infer pay zones or predict the composition and properties of reservoir fluids because the gas composition is completely changed. [ABSTRACT FROM AUTHOR]

Published
2024
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4. 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

Author

Shuai, Yanhua, Douglas, Peter MJ, Zhang, Shuichang, Stolper, Daniel A, Ellis, Geoffrey S, Lawson, Michael, Lewan, Michael D, Formolo, Michael, Mi, Jingkui, He, Kun, Hu, Guoyi, and Eiler, John M

Subjects
Thermogenic methane, Clumped isotopologues, Non-equilibrium, Coal, Shale, Geochemistry, Geology, Physical Geography and Environmental Geoscience, Geochemistry & Geophysics
Abstract

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. However, kinetic processes during generation, modification, or transport of natural materials can also affect their clumped-isotope compositions. Herein, we show that methane generated experimentally by closed-system hydrous pyrolysis of shale or nonhydrous pyrolysis of coal yields clumped-isotope compositions consistent with an equilibrium distribution of isotopologues under some experimental conditions (temperature–time conditions corresponding to ‘low,’ ‘mature,’ and ‘over-mature’ stages of catagenesis), but can have non-equilibrium (i.e., kinetically controlled) distributions under other experimental conditions (‘high’ to ‘over-mature’ stages), particularly for pyrolysis of coal. Non-equilibrium compositions, when present, lead the measured proportions of clumped species to be lower than expected for equilibrium at the experimental temperature, and in some cases to be lower than a random distribution of isotopes (i.e., negative Δ18 values). We propose that the consistency with equilibrium for methane formed by relatively low temperature pyrolysis reflects local reversibility of isotope exchange reactions involving a reactant or transition state species during demethylation of one or more components of kerogen. Non-equilibrium clumped-isotope compositions occur under conditions where 'secondary’ cracking of retained oil in shale or wet gas hydrocarbons (C2-5, especially ethane) in coal is prominent. We suggest these non-equilibrium isotopic compositions are the result of the expression of kinetic isotope effects during the irreversible generation of methane from an alkyl precursor. Other interpretations are also explored. These findings provide new insights into the chemistry of thermogenic methane generation, and may provide an explanation of the elevated apparent temperatures recorded by the methane clumped-isotope thermometer in some natural gases. However, it remains unknown if the laboratory experiments capture the processes that occur at the longer time and lower temperatures of natural gas formation.

Published
2018

7. Assessment of undiscovered conventional oil and gas resources in postsalt reservoirs of the West-Central Coastal Province of Africa, 2022

Author

Schenk, Christopher J., primary, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Le, Phuong A., additional, Cicero, Andrea D., additional, Drake, Ronald M., additional, Ellis, Geoffrey S., additional, Finn, Thomas M., additional, Gardner, Michael H., additional, Gelman, Sarah E., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Lagesse, Jenny H., additional, Leathers-Miller, Heidi M., additional, Marra, Kristen R., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2024
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8. Assessment of undiscovered continuous oil and gas resources in Upper Cretaceous marine shales of the Raton Basin-Sierra Grande Uplift Province, Colorado and New Mexico, 2022

Author

Finn, Thomas M., primary, Schenk, Christopher J., additional, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Leathers-Miller, Heidi M., additional, Le, Phuong A., additional, Cicero, Andrea D., additional, Ellis, Geoffrey S., additional, Gardner, Michael H., additional, Gelman, Sarah E., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Kinney, Scott A., additional, Lagesse, Jenny H., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2024
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14. Assessment of continuous oil and gas resources in the Bakken Formation of northwest Montana, 2022

Author

Schenk, Christopher J., primary, Gardner, Michael H., additional, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Le, Phuong A., additional, Cicero, Andrea D., additional, Drake, Ronald M., additional, Ellis, Geoffrey S., additional, Finn, Thomas M., additional, Gelman, Sarah E., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Lagesse, Jenny H., additional, Leathers-Miller, Heidi M., additional, Marra, Kristen R., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2023
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15. Assessment of undiscovered conventional oil and gas resources in the offshore Salt Basin area of Morocco, 2021

Author

Schenk, Christopher J., primary, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Le, Phuong A., additional, Cicero, Andrea D., additional, Drake, Ronald M., additional, Ellis, Geoffrey S., additional, Finn, Thomas M., additional, Gardner, Michael H., additional, Gelman, Sarah E., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Lagesse, Jenny H., additional, Leathers-Miller, Heidi M., additional, Marra, Kristen R., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2023
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25. Assessment of undiscovered conventional oil and gas resources of the Montana Thrust Belt Province, 2021

Author

Schenk, Christopher J., primary, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Le, Phuong A., additional, Cicero, Andrea D., additional, Drake, Ronald M., additional, Ellis, Geoffrey S., additional, Finn, Thomas M., additional, Gardner, Michael H., additional, Gelman, Sarah E., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Lagesse, Jenny H., additional, Leathers-Miller, Heidi M., additional, Marra, Kristen R., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2022
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26. Assessment of undiscovered conventional oil and gas resources of the Senegal Basin Province of northwest Africa, 2021

Author

Schenk, Christopher J., primary, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Le, Phuong A., additional, Cicero, Andrea D., additional, Drake, Ronald M., additional, Ellis, Geoffrey S., additional, Finn, Thomas M., additional, Gardner, Michael H., additional, Gelman, Sarah E., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Lagesse, Jenny H., additional, Leathers-Miller, Heidi M., additional, Marra, Kristen R., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2022
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33. ICDP workshop on the Lake Tanganyika Scientific Drilling Project: A late Miocene-present record of climate, rifting, and ecosystem evolution from the world's oldest tropical lake

Author

Russell, James, Barker, P A, Cohen, Andrew S, Ivory, Sarah J, Kimirei, I A, Lane, Christine S, Leng, Melanie J., Maganza, Neema, McGlue, Michael Matthew, Msaky, Emma S, Noren, Anders J, Boush, Lisa Park, Salzburger, Walter, Scholz, Christopher A, Tiedemann, Ralph, Nuru, Shaidu, Albrecht, Christian, Ali, Rahma, Arrowsmith, Ramón Ja, Asanga, Danstan, Asmerom, Yemane, Bakundukize, Charles, Bauersachs, Thorsten, Beck, Catherine C, Berke, Melissa A, Beverley, Emily, Blaauw, Martin, Brown, Erik T, Campisano, Christopher J, Carrapa, Bárbara, Castaûeda, Isla, Dee, Sylvia G, Deino, Alan L, Ebinger, Cynthia J, Ellis, Geoffrey S, Foerster, Verena E, Fontijn, Karen, Gehrels, George E, Indemaur, Adrian, Jovanovska, Elena, Junginger, Annett, Kaboth, Stefanie, Kallmeyer, Jens, King, John W, Konecky, Bronwen L, Mark, Darren F, McIntyre, Peter B, Michel, Ellinor, Mkuu, Doreen, Morgan, Leah, Mtetela, Cassy, Muderwha, Nshombo, Muirhead, James D, Mumbi, Cassian T, Muschick, Mo, Nahimana, David, Ngowi, Venosa, Njiko, Pashcal, Nkenyeli, Simon, Nkotagu, Hudson H, Ntakimazi, Gaspard, Oppo, Davide, Purkamo, Lotta, Rick, Jessica A, Roberts, Helen M, Ronco, Fabrizia, Sangweni, Charles, Shaghude, Yohanna W, Shigela, Josephat, Shillington, Donna J, Sophia, Chen Shuang, Sier, Mark Jan, Soreghan, Michael James, Spanbauer, Trisha L, Spencer-Jones, Charlotte L, Staff, Richard A, Stone, Jeffery R, Todd, Jonathan A, Trauth, Martin H, Van Bocxlaer, Bert, Viehberg, Finn A, Vogel, Hendrik, Vonhof, Hubert, Wolff, Christian, Wu, Qinglong, Yost, Chad L, Zeeden, Christian, Russell, James, Barker, P A, Cohen, Andrew S, Ivory, Sarah J, Kimirei, I A, Lane, Christine S, Leng, Melanie J., Maganza, Neema, McGlue, Michael Matthew, Msaky, Emma S, Noren, Anders J, Boush, Lisa Park, Salzburger, Walter, Scholz, Christopher A, Tiedemann, Ralph, Nuru, Shaidu, Albrecht, Christian, Ali, Rahma, Arrowsmith, Ramón Ja, Asanga, Danstan, Asmerom, Yemane, Bakundukize, Charles, Bauersachs, Thorsten, Beck, Catherine C, Berke, Melissa A, Beverley, Emily, Blaauw, Martin, Brown, Erik T, Campisano, Christopher J, Carrapa, Bárbara, Castaûeda, Isla, Dee, Sylvia G, Deino, Alan L, Ebinger, Cynthia J, Ellis, Geoffrey S, Foerster, Verena E, Fontijn, Karen, Gehrels, George E, Indemaur, Adrian, Jovanovska, Elena, Junginger, Annett, Kaboth, Stefanie, Kallmeyer, Jens, King, John W, Konecky, Bronwen L, Mark, Darren F, McIntyre, Peter B, Michel, Ellinor, Mkuu, Doreen, Morgan, Leah, Mtetela, Cassy, Muderwha, Nshombo, Muirhead, James D, Mumbi, Cassian T, Muschick, Mo, Nahimana, David, Ngowi, Venosa, Njiko, Pashcal, Nkenyeli, Simon, Nkotagu, Hudson H, Ntakimazi, Gaspard, Oppo, Davide, Purkamo, Lotta, Rick, Jessica A, Roberts, Helen M, Ronco, Fabrizia, Sangweni, Charles, Shaghude, Yohanna W, Shigela, Josephat, Shillington, Donna J, Sophia, Chen Shuang, Sier, Mark Jan, Soreghan, Michael James, Spanbauer, Trisha L, Spencer-Jones, Charlotte L, Staff, Richard A, Stone, Jeffery R, Todd, Jonathan A, Trauth, Martin H, Van Bocxlaer, Bert, Viehberg, Finn A, Vogel, Hendrik, Vonhof, Hubert, Wolff, Christian, Wu, Qinglong, Yost, Chad L, and Zeeden, Christian

Abstract

The Neogene and Quaternary are characterized by enormous changes in global climate and environments, including global cooling and the establishment of northern high-latitude glaciers. These changes reshaped global ecosystems, including the emergence of tropical dry forests and savannahs that are found in Africa today, which in turn may have influenced the evolution of humans and their ancestors. However, despite decades of research we lack long, continuous, well-resolved records of tropical climate, ecosystem changes, and surface processes necessary to understand their interactions and influences on evolutionary processes. Lake Tanganyika, Africa, contains the most continuous, long continental climate record from the mid-Miocene (∼ 10 Ma) to the present anywhere in the tropics and has long been recognized as a top-priority site for scientific drilling. The lake is surrounded by the Miombo woodlands, part of the largest dry tropical biome on Earth. Lake Tanganyika also harbors incredibly diverse endemic biota and an entirely unexplored deep microbial biosphere, and it provides textbook examples of rift segmentation, fault behavior, and associated surface processes. To evaluate the interdisciplinary scientific opportunities that an ICDP drilling program at Lake Tanganyika could offer, more than 70 scientists representing 12 countries and a variety of scientific disciplines met in Dar es Salaam, Tanzania, in June 2019. The team developed key research objectives in basin evolution, source-to-sink sedimentology, organismal evolution, geomicrobiology, paleoclimatology, paleolimnology, terrestrial paleoecology, paleoanthropology, and geochronology to be addressed through scientific drilling on Lake Tanganyika. They also identified drilling targets and strategies, logistical challenges, and education and capacity building programs to be carried out through the project. Participants concluded that a drilling program at Lake Tanganyika would produce the first continuous Mioce, SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2020

36. Assessment of undiscovered continuous oil resources in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana, 2021

Author

Marra, Kristen R., primary, Mercier, Tracey J., additional, Gelman, Sarah E., additional, Schenk, Christopher J., additional, Woodall, Cheryl A., additional, Cicero, Andrea D., additional, Drake, Ronald M., additional, Ellis, Geoffrey S., additional, Finn, Thomas M., additional, Gardner, Michael H., additional, Hearon, Jane S., additional, Johnson, Benjamin G., additional, Lagesse, Jenny H., additional, Le, Phuong A., additional, Leathers-Miller, Heidi M., additional, Timm, Kira K., additional, and Young, Scott S., additional

Published
2021
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45. Assessment of undiscovered oil and gas resources in the Upper Cretaceous Austin Chalk and Tokio and Eutaw Formations, U.S. Gulf Coast, 2019

Author

Pitman, Janet K., primary, Paxton, Stanley T., additional, Kinney, Scott A., additional, Whidden, Katherine J., additional, Haines, Seth S., additional, Varela, Brian A., additional, Mercier, Tracey J., additional, Woodall, Cheryl A., additional, Schenk, Christopher J., additional, Leathers-Miller, Heidi M., additional, Pearson, Ofori N., additional, Burke, Lauri A., additional, Le, Phuong A., additional, Birdwell, Justin E., additional, Gianoutsos, Nicholas J., additional, French, Katherine L., additional, Drake, Ronald M., additional, Finn, Thomas M., additional, Ellis, Geoffrey S., additional, Gaswirth, Stephanie B., additional, Marra, Kristen R., additional, Tennyson, Marilyn E., additional, and Shorten, Chilisa M., additional

Published
2020
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47. Assessment of continuous oil and gas resources in the niobrara interval of the Cody Shale, Bighorn Basin Province, Wyoming and Montana, 2019

Author

Finn, Thomas M., primary, Schenk, Christopher J., additional, Mercier, Tracey J., additional, Tennyson, Marilyn E., additional, Le, Phuong A., additional, Brownfield, Michael E., additional, Marra, Kristen R., additional, Leathers-Miller, Heidi M., additional, Drake, Ronald M., additional, Woodall, Cheryl A., additional, Pitman, Janet K., additional, Ellis, Geoffrey S., additional, and Kinney, Scott A., additional

Published
2019
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48. Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019

Author

Higley, Debra K., primary, Enomoto, Catherine E, additional, Leathers-Miller, Heidi M., additional, Ellis, Geoffrey S., additional, Mercier, Tracey J., additional, Schenk, Christopher J., additional, Trippi, Michael H., additional, Le, Phuong A., additional, Brownfield, Michael E., additional, Woodall, Cheryl A., additional, Marra, Kristen R., additional, and Tennyson, Marilyn E., additional

Published
2019
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49. Development of Hydrocarbon Gas Reference Materials for Stable Isotopic Composition (δ13C and δ²H).

Author

Ellis, Geoffrey S. and Dias, Robert F.

Subjects
HYDROCARBONS, STABLE isotope tracers, DATA analysis, POWER resources
Abstract

A suite of gas standards was developed to serve as international secondary reference materials (RMs) for the determination of the compound-specific carbon-13/carbon-12 (d13C) and hydrogen-2/hydrogen-1 (d2H) values of hydrocarbon gases. This report provides background information on the project, the methods used to produce and analyze the gases, as well as the data analysis and recommended stable isotopic values. Additionally, samples of older hydrocarbon gas RMs no longer available were analyzed along with the new RMs to allow for traceability to historical data. These secondary RMs are intended for interlaboratory standardization and traceability to primary RMs. The gaseous RMs are currently (at time of publication) available for purchase from the U.S. Geological Survey Energy Resources Program. [ABSTRACT FROM AUTHOR]

Published
2022
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