Geoffrey S Ellis (Former Employee)
Science and Products
Filter Total Items: 81
Gas storage in the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, Oklahoma: how much of a role do the cherts play? Gas storage in the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, Oklahoma: how much of a role do the cherts play?
How gas is stored in shale-gas systems is a critical element in characterizing these potentially prolific, low-porosity/permeability reservoirs. An integrated mineralogic, geochemical, and porosity/permeability study is of the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, southern Oklahoma, at locations previously described through detailed stratigraphic and...
Authors
Neil S. Fishman, Geoffrey S. Ellis, Stanley T. Paxton, Marvin M. Abbott, Adam Boehlke
Experimental investigation on thermochemical sulfate reduction by H2S initiation Experimental investigation on thermochemical sulfate reduction by H2S initiation
Hydrogen sulfide (H2S) is known to catalyze thermochemical sulfate reduction (TSR) by hydrocarbons (HC), but the reaction mechanism remains unclear. To understand the mechanism of this catalytic reaction, a series of isothermal gold-tube hydrous pyrolysis experiments were conducted at 330 °C for 24 h under a constant confining pressure of 24.1 MPa. The reactants used were saturated HC...
Authors
Tongwei Zhang, Alon Amrani, Geoffrey S Ellis, Qisheng Ma, Yongchun Tang, David Applegate
The role of labile sulfur compounds in thermal chemical sulfate reduction The role of labile sulfur compounds in thermal chemical sulfate reduction
The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A...
Authors
Alon Amrani, Geoffrey S Ellis, Tongwei Zhang, Qisheng Ma, Yongchun Tang
Theoretical study on the reactivity of sulfate species with hydrocarbons Theoretical study on the reactivity of sulfate species with hydrocarbons
The abiotic, thermochemically controlled reduction of sulfate to hydrogen sulfide coupled with the oxidation of hydrocarbons, is termed thermochemical sulfate reduction (TSR), and is an important alteration process that affects petroleum accumulations in nature. Although TSR is commonly observed in high-temperature carbonate reservoirs, it has proven difficult to simulate in the...
Authors
Qisheng Ma, Geoffrey S Ellis, Alon Amrani, Tongwei Zhang, Yongchun Tang
Distinguishing solid bitumens formed by thermochemical sulfate reduction and thermal chemical alteration Distinguishing solid bitumens formed by thermochemical sulfate reduction and thermal chemical alteration
Insoluble solid bitumens are organic residues that can form by the thermal chemical alteration (TCA) or thermochemical sulfate reduction (TSR) of migrated petroleum. TCA may actually encompass several low temperature processes, such as biodegradation and asphaltene precipitation, followed by thermal alteration. TSR is an abiotic redox reaction where petroleum is oxidized by sulfate. It...
Authors
S.R. Kelemen, C.C. Walters, P.J. Kwiatek, M. Afeworki, M. Sansone, H. Freund, R.J. Pottorf, H.G. Machel, T. Zhang, G.S. Ellis, Y. Tang, K. E. Peters
Geochemical signatures of thermochemical sulfate reduction in controlled hydrous pyrolysis experiments Geochemical signatures of thermochemical sulfate reduction in controlled hydrous pyrolysis experiments
A series of gold tube hydrous pyrolysis experiments was conducted in order to investigate the effect of thermochemical sulfate reduction (TSR) on gas generation, residual saturated hydrocarbon compositional alteration, and solid pyrobitumen formation. The intensity of TSR significantly depends on the H2O/MgSO4 mole ratio, the smaller the ratio, the stronger the oxidizing conditions...
Authors
T. Zhang, G.S. Ellis, C.C. Walters, S.R. Kelemen, Kang-shi Wang, Y. Tang
Organic contaminants associated with suspended sediment collected during five cruises of the Mississippi River and its principal tributaries, May 1988 to June 1990 Organic contaminants associated with suspended sediment collected during five cruises of the Mississippi River and its principal tributaries, May 1988 to June 1990
Suspended-sediment samples were obtained from sites along the Mississippi River and its principal tributaries to determine the presence of halogenated hydrophobic organic compounds on the suspended sediment smaller than 63 micrometers. Sample collection involved pumping discharge-weighted volumes of river water along a cross section of the river into a continuous-flow centrifuge to...
Authors
Colleen E. Rostad, LaDonna M. Bishop, Geoffrey S. Ellis, Thomas J. Leiker, Stephanie G. Monsterleet, Wilfred E. Pereira
Paleolimnology of Lake Tanganyika, East Africa, over the past 100 k yr Paleolimnology of Lake Tanganyika, East Africa, over the past 100 k yr
New sediment core data from a unique slow-sedimentation rate site in Lake Tanganyika contain a much longer and continuous record of limnological response to climate change than have been previously observed in equatorial regions of central Africa. The new core site was first located through an extensive seismic reflection survey over the Kavala Island Ridge (KIR), a sedimented basement...
Authors
C.A. Scholz, J.W. King, G.S. Ellis, Peter K. Swart, J.C. Stager, Steven M. Colman
Evaluation of lipid-containing semipermeable membrane devices for monitoring organochlorine contaminants in the Upper Mississippi river Evaluation of lipid-containing semipermeable membrane devices for monitoring organochlorine contaminants in the Upper Mississippi river
Organochlorine contaminants sequestered in lipid-containing semipermeable membrane devices (SPMDs) were compared to those found in tangential-flow ultrafilter permeates as part of a pilot study at 10 sites in the Upper Mississippi River system. Caged and feral fish from three primary sites were also analyzed for comparison. Concentrated organochlorine (OC) compounds were readily...
Authors
Geoffrey S. Ellis, Colleen E. Rostad, James N. Huckins, Christopher J. Schmitt, Patrick MacCarthy
Science and Products
Filter Total Items: 81
Gas storage in the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, Oklahoma: how much of a role do the cherts play? Gas storage in the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, Oklahoma: how much of a role do the cherts play?
How gas is stored in shale-gas systems is a critical element in characterizing these potentially prolific, low-porosity/permeability reservoirs. An integrated mineralogic, geochemical, and porosity/permeability study is of the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, southern Oklahoma, at locations previously described through detailed stratigraphic and...
Authors
Neil S. Fishman, Geoffrey S. Ellis, Stanley T. Paxton, Marvin M. Abbott, Adam Boehlke
Experimental investigation on thermochemical sulfate reduction by H2S initiation Experimental investigation on thermochemical sulfate reduction by H2S initiation
Hydrogen sulfide (H2S) is known to catalyze thermochemical sulfate reduction (TSR) by hydrocarbons (HC), but the reaction mechanism remains unclear. To understand the mechanism of this catalytic reaction, a series of isothermal gold-tube hydrous pyrolysis experiments were conducted at 330 °C for 24 h under a constant confining pressure of 24.1 MPa. The reactants used were saturated HC...
Authors
Tongwei Zhang, Alon Amrani, Geoffrey S Ellis, Qisheng Ma, Yongchun Tang, David Applegate
The role of labile sulfur compounds in thermal chemical sulfate reduction The role of labile sulfur compounds in thermal chemical sulfate reduction
The reduction of sulfate to sulfide coupled with the oxidation of hydrocarbons to carbon dioxide, commonly referred to as thermochemical sulfate reduction (TSR), is an important abiotic alteration process that most commonly occurs in hot carbonate petroleum reservoirs. In the present study we focus on the role that organic labile sulfur compounds play in increasing the rate of TSR. A...
Authors
Alon Amrani, Geoffrey S Ellis, Tongwei Zhang, Qisheng Ma, Yongchun Tang
Theoretical study on the reactivity of sulfate species with hydrocarbons Theoretical study on the reactivity of sulfate species with hydrocarbons
The abiotic, thermochemically controlled reduction of sulfate to hydrogen sulfide coupled with the oxidation of hydrocarbons, is termed thermochemical sulfate reduction (TSR), and is an important alteration process that affects petroleum accumulations in nature. Although TSR is commonly observed in high-temperature carbonate reservoirs, it has proven difficult to simulate in the...
Authors
Qisheng Ma, Geoffrey S Ellis, Alon Amrani, Tongwei Zhang, Yongchun Tang
Distinguishing solid bitumens formed by thermochemical sulfate reduction and thermal chemical alteration Distinguishing solid bitumens formed by thermochemical sulfate reduction and thermal chemical alteration
Insoluble solid bitumens are organic residues that can form by the thermal chemical alteration (TCA) or thermochemical sulfate reduction (TSR) of migrated petroleum. TCA may actually encompass several low temperature processes, such as biodegradation and asphaltene precipitation, followed by thermal alteration. TSR is an abiotic redox reaction where petroleum is oxidized by sulfate. It...
Authors
S.R. Kelemen, C.C. Walters, P.J. Kwiatek, M. Afeworki, M. Sansone, H. Freund, R.J. Pottorf, H.G. Machel, T. Zhang, G.S. Ellis, Y. Tang, K. E. Peters
Geochemical signatures of thermochemical sulfate reduction in controlled hydrous pyrolysis experiments Geochemical signatures of thermochemical sulfate reduction in controlled hydrous pyrolysis experiments
A series of gold tube hydrous pyrolysis experiments was conducted in order to investigate the effect of thermochemical sulfate reduction (TSR) on gas generation, residual saturated hydrocarbon compositional alteration, and solid pyrobitumen formation. The intensity of TSR significantly depends on the H2O/MgSO4 mole ratio, the smaller the ratio, the stronger the oxidizing conditions...
Authors
T. Zhang, G.S. Ellis, C.C. Walters, S.R. Kelemen, Kang-shi Wang, Y. Tang
Organic contaminants associated with suspended sediment collected during five cruises of the Mississippi River and its principal tributaries, May 1988 to June 1990 Organic contaminants associated with suspended sediment collected during five cruises of the Mississippi River and its principal tributaries, May 1988 to June 1990
Suspended-sediment samples were obtained from sites along the Mississippi River and its principal tributaries to determine the presence of halogenated hydrophobic organic compounds on the suspended sediment smaller than 63 micrometers. Sample collection involved pumping discharge-weighted volumes of river water along a cross section of the river into a continuous-flow centrifuge to...
Authors
Colleen E. Rostad, LaDonna M. Bishop, Geoffrey S. Ellis, Thomas J. Leiker, Stephanie G. Monsterleet, Wilfred E. Pereira
Paleolimnology of Lake Tanganyika, East Africa, over the past 100 k yr Paleolimnology of Lake Tanganyika, East Africa, over the past 100 k yr
New sediment core data from a unique slow-sedimentation rate site in Lake Tanganyika contain a much longer and continuous record of limnological response to climate change than have been previously observed in equatorial regions of central Africa. The new core site was first located through an extensive seismic reflection survey over the Kavala Island Ridge (KIR), a sedimented basement...
Authors
C.A. Scholz, J.W. King, G.S. Ellis, Peter K. Swart, J.C. Stager, Steven M. Colman
Evaluation of lipid-containing semipermeable membrane devices for monitoring organochlorine contaminants in the Upper Mississippi river Evaluation of lipid-containing semipermeable membrane devices for monitoring organochlorine contaminants in the Upper Mississippi river
Organochlorine contaminants sequestered in lipid-containing semipermeable membrane devices (SPMDs) were compared to those found in tangential-flow ultrafilter permeates as part of a pilot study at 10 sites in the Upper Mississippi River system. Caged and feral fish from three primary sites were also analyzed for comparison. Concentrated organochlorine (OC) compounds were readily...
Authors
Geoffrey S. Ellis, Colleen E. Rostad, James N. Huckins, Christopher J. Schmitt, Patrick MacCarthy
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