Sample records for hydrate cxs applied

  1. To appear in International Journal of Advances in Engineering Sciences and Applied Mathematics (2010). Critical Observations for the Evaluation of Cement Hydration Models

    E-Print Network [OSTI]

    Bentz, Dale P.

    2010-01-01T23:59:59.000Z

    (2010). Critical Observations for the Evaluation of Cement Hydration Models Dale P. Bentz Engineering of computer models for cement hydration and microstructure development, with an explicit consideration of experimental observations concerning the influence of water-to-cement ratio, cement particle size distribution

  2. Hydrate-phobic surfaces

    E-Print Network [OSTI]

    Smith, Jonathan David, S.M. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    Clathrate hydrate formation and subsequent plugging of deep-sea oil and gas pipelines represent a significant bottleneck for ultra deep-sea production. Current methods for hydrate mitigation focus on injecting thermodynamic ...

  3. Seismic technology will be of key importance for evaluat-ing gas-hydrate resources, particularly across the Gulf of

    E-Print Network [OSTI]

    Texas at Austin, University of

    Seismic technology will be of key importance for evaluat- ing gas-hydrate resources, particularly to be acquired. To apply seismic technology to gas-hydrate studies in the gulf in an optimal manner, it is essential to understand the seismic target that has to be analyzed. What is gas hydrate? Gas hydrate

  4. Hydration-dependent dynamic crossover phenomenon in protein hydration water

    E-Print Network [OSTI]

    Wang, Zhe

    The characteristic relaxation time ? of protein hydration water exhibits a strong hydration level h dependence. The dynamic crossover is observed when h is higher than the monolayer hydration level h[subscript c] =0.2–0.25 ...

  5. Methane Hydrate Field Program

    SciTech Connect (OSTI)

    None

    2013-12-31T23:59:59.000Z

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report. • Historical Methane Hydrate Project Review Report • Methane Hydrate Workshop Report • Topical Report: Marine Methane Hydrate Field Research Plan • Final Scientific/Technical Report

  6. Apply

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProductsAlternative FuelsSanta3Appliance andApplicationBerkeleyAppliedApply

  7. Chemically reacting plumes, gas hydrate dissociation and dendrite solidification

    E-Print Network [OSTI]

    Conroy, Devin Thomas

    2008-01-01T23:59:59.000Z

    II Gas hydrates Introductionto gas hydrates . . . . . . . . . . 1.127 Gas hydrate dissociation in porous media . 1.

  8. CX-009465: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Categorical Exclusion Determination Temporal Characterization of Hydrates System Dynamics Beneath Seafloor Mounds: Integrating Time-Lapse CX(s) Applied: B3.6 Date: 10182012...

  9. CX-009462: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Categorical Exclusion Determination Temporal Characterization of Hydrates System Dynamics Beneath Seafloor Mounds: Integrating Time-Lapse CX(s) Applied: A9, A11 Date: 1018...

  10. CX-009463: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Categorical Exclusion Determination Temporal Characterization of Hydrates System Dynamics Beneath Seafloor Mounds: Integrating Time-Lapse CX(s) Applied: B3.6 Date: 10182012...

  11. CX-009464: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Categorical Exclusion Determination Temporal Characterization of Hydrates System Dynamics beneath Seafloor Mounds: Integrating Time-Lapse CX(s) Applied: A9, A11 Date: 1018...

  12. CX-000734: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    CX-000734: Categorical Exclusion Determination Detection and Production of Methane Hydrates CX(s) Applied: A9 Date: 01222010 Location(s): Stillwater, Oklahoma Office(s):...

  13. CX-000733: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    CX-000733: Categorical Exclusion Determination Detection and Production of Methane Hydrates CX(s) Applied: A9 Date: 01222010 Location(s): Austin, Texas Office(s): Fossil...

  14. CX-010941: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    CX-010941: Categorical Exclusion Determination Assessing the Response of Methane Hydrates to Environmental Change at the Svalbard Continental Margin CX(s) Applied: B3.6,...

  15. Fe-containing phases in hydrated cements

    SciTech Connect (OSTI)

    Dilnesa, B.Z., E-mail: belay.dilnesa@gmail.com [Empa, Laboratory for Concrete and Construction Chemistry, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Wieland, E. [Paul Scherrer Institute, Laboratory for Waste Management, 5232 Villigen PSI (Switzerland); Lothenbach, B. [Empa, Laboratory for Concrete and Construction Chemistry, Überlandstrasse 129, 8600 Dübendorf (Switzerland); Dähn, R. [Paul Scherrer Institute, Laboratory for Waste Management, 5232 Villigen PSI (Switzerland); Scrivener, K.L. [Ecole Polytechnique Federal de Lausanne (EPFL), Laboratory for Construction Materials, 1015 Lausanne (Switzerland)

    2014-04-01T23:59:59.000Z

    In this study synchrotron X-ray absorption spectroscopy (XAS) has been applied, an element specific technique which allows Fe-containing phases to be identified in the complex mineral mixture of hydrated cements. Several Fe species contributed to the overall Fe K-edge spectra recorded on the cement samples. In the early stage of cement hydration ferrite was the dominant Fe-containing mineral. Ferrihydrite was detected during the first hours of the hydration process. After 1 day the formation of Al- and Fe-siliceous hydrogarnet was observed, while the amount of ferrihydrite decreased. The latter finding agrees with thermodynamic modeling, which predicts the formation of Fe-siliceous hydrogarnet in Portland cement systems. The presence of Al- and Fe-containing siliceous hydrogarnet was further substantiated in the residue of hydrated cement by performing a selective dissolution procedure. - Highlights: • Fe bound to ferrihydrite at early age hydration • Fe found to be stable in siliceous hydrogarnet at longer term age hydration • Fe-containing AFt and AFm phases are less stable than siliceous hydrogarnet. • The study demonstrates EXAFS used to identify amorphous or poorly crystalline phases.

  16. X-ray Scanner for ODP Leg 204: Drilling Gas Hydrates on Hydrate Ridge, Cascadia Continental Margin

    E-Print Network [OSTI]

    Freifeld, Barry; Kneafsey, Tim; Pruess, Jacob; Reiter, Paul; Tomutsa, Liviu

    2002-01-01T23:59:59.000Z

    International Conference of Gas Hydrates, Yokohama, Japan.Prospectus, Drilling Gas Hydrates On Hydrate Ridge, CascadiaLeg 204: Drilling Gas Hydrates on Hydrate Ridge, Cascadia

  17. (GAS HYDRATES) 2 ()

    E-Print Network [OSTI]

    : ... ... .... .... «» , 28 2007 : « » #12; · ·· #12; 2 #12; (GAS HYDRATES) #12;Y · µ 2 µ () µ · µ µ · µ µ µ ·µ: - - µ CO2 - - #12; - 3S·2M·1L·34H3S

  18. Marine electromagnetic methods for gas hydrate characterization

    E-Print Network [OSTI]

    Weitemeyer, Karen Andrea

    2008-01-01T23:59:59.000Z

    1.2 Gas Hydrates . . . . . . . .1.2.1 Distribution of Gas Hydrates . . . . . . . . . . .1.2.2 Importance of Gas Hydrates . . . . .

  19. Marine Electromagnetic Methods for Gas Hydrate Characterization

    E-Print Network [OSTI]

    Weitemeyer, Karen A

    2008-01-01T23:59:59.000Z

    1.2 Gas Hydrates . . . . . . . .1.2.1 Distribution of Gas Hydrates . . . . . . . . . . .1.2.2 Importance of Gas Hydrates . . . . .

  20. Imaging Hydrated Microbial Extracellular Polymers: Comparative...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy . Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron...

  1. Study on small-strain behaviours of methane hydrate sandy sediments using discrete element method

    SciTech Connect (OSTI)

    Yu Yanxin; Cheng Yipik [Department of Civil, Environmental and Geomatic Engineering, University College London (UCL), Gower Street, London, WC1E 6BT (United Kingdom); Xu Xiaomin; Soga, Kenichi [Geotechnical and Environmental Research Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ (United Kingdom)

    2013-06-18T23:59:59.000Z

    Methane hydrate bearing soil has attracted increasing interest as a potential energy resource where methane gas can be extracted from dissociating hydrate-bearing sediments. Seismic testing techniques have been applied extensively and in various ways, to detect the presence of hydrates, due to the fact that hydrates increase the stiffness of hydrate-bearing sediments. With the recognition of the limitations of laboratory and field tests, wave propagation modelling using Discrete Element Method (DEM) was conducted in this study in order to provide some particle-scale insights on the hydrate-bearing sandy sediment models with pore-filling and cementation hydrate distributions. The relationship between shear wave velocity and hydrate saturation was established by both DEM simulations and analytical solutions. Obvious differences were observed in the dependence of wave velocity on hydrate saturation for these two cases. From the shear wave velocity measurement and particle-scale analysis, it was found that the small-strain mechanical properties of hydrate-bearing sandy sediments are governed by both the hydrate distribution patterns and hydrate saturation.

  2. Rapid gas hydrate formation process

    DOE Patents [OSTI]

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15T23:59:59.000Z

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  3. Gas hydrate cool storage system

    DOE Patents [OSTI]

    Ternes, M.P.; Kedl, R.J.

    1984-09-12T23:59:59.000Z

    The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)

  4. The Great Gas Hydrate Escape

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and hydrogen pack into gas hydrates could enlighten alternative fuel production and carbon dioxide storage January 25, 2012 | Tags: Carver, Chemistry, Energy Technologies,...

  5. Acoustic and Thermal Characterization of Oil Migration, Gas Hydrates Formation and Silica Diagenesis

    E-Print Network [OSTI]

    Guerin, Gilles

    Rights Reserved #12;ABSTRACT Acoustic and Thermal Characterization of Oil Migration, Gas HydratesAcoustic and Thermal Characterization of Oil Migration, Gas Hydrates Formation and Silica is applied to two reservoirs in the Gulf of Mexico. In the last chapter, we present the thermal regime

  6. SUESS ET AL.: SEA FLOOR METHANE HYDRATES AT HYDRATE RIDGE, CASCADIA MARGIN Sea Floor Methane Hydrates at Hydrate Ridge, Cascadia Margin

    E-Print Network [OSTI]

    Goldfinger, Chris

    a variety of gas hydrates in near-surface sediments. Hydrate formation and destruction continuously shape established that the uppermost sediment column contains several distinct layers of gas hydrate which the seafloor to the atmosphere. 1. INTRODUCTION The biogeochemical processes associated with gas hydrate

  7. Dynamics of Protein Hydration Water

    E-Print Network [OSTI]

    M. Wolf; S. Emmert; R. Gulich; P. Lunkenheimer; A. Loidl

    2014-12-08T23:59:59.000Z

    We present the frequency- and temperature-dependent dielectric properties of lysozyme solutions in a broad concentration regime, measured at subzero temperatures and compare the results with measurements above the freezing point of water and on hydrated lysozyme powder. Our experiments allow examining the dynamics of unfreezable hydration water in a broad temperature range including the so-called No Man's Land (160 - 235 K). The obtained results prove the bimodality of the hydration shell dynamics and are discussed in the context of the highly-debated fragile-to-strong transition of water.

  8. Fundamental measure theory of hydrated hydrocarbons

    E-Print Network [OSTI]

    Victor F. Sokolov; Gennady N. Chuev

    2006-04-13T23:59:59.000Z

    To calculate the solvation of hydrophobic solutes we have developed the method based on the fundamental measure treatment of the density functional theory. This method allows us to carry out calculations of density profiles and the solvation energy for various hydrophobic molecules with a high accuracy. We have applied the method to the hydration of various hydrocarbons (linear, branched and cyclic). The calculations of the entropic and the enthalpic parts are also carried out. We have examined a question about temperature dependence of the entropy convergence. Finally, we have calculated the mean force potential between two large hydrophobic nanoparticles immersed in water.

  9. Strategies for gas production from oceanic Class 3 hydrate accumulations

    E-Print Network [OSTI]

    Moridis, George J.; Reagan, Matthew T.

    2007-01-01T23:59:59.000Z

    coexistence of aqueous, gas and hydrate phases, indicatingIntrinsic Rate of Methane Gas Hydrate Decomposition”, Chem.Makogon, Y.F. , “Gas hydrates: frozen energy,” Recherche

  10. Response of oceanic hydrate-bearing sediments to thermal stresses

    E-Print Network [OSTI]

    Moridis, G.J.; Kowalsky, M.B.

    2006-01-01T23:59:59.000Z

    c) aqueous, gas and hydrate phase saturations, (d) waterIntrinsic Rate of Methane Gas Hydrate Decomposition”, Chem.Western Nankai Trough”, in Gas Hydrates: Challenges for the

  11. Examination of Hydrate Formation Methods: Trying to Create Representative Samples

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    permeability measurements of gas hydrate-bearing sediments,International Conference on Gas Hydrates, edited, p. 1058,2009), Influence of gas hydrate morphology on the seismic

  12. Preliminary relative permeability estimates of methane hydrate-bearing sand

    E-Print Network [OSTI]

    Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.

    2006-01-01T23:59:59.000Z

    gas production from gas hydrate reservoirs. We estimated theof gas production from gas hydrate reservoirs. Fieldpermeability function in gas hydrate-bearing sediments is

  13. Modeling pure methane hydrate dissociation using a numerical simulator from a novel combination of X-ray computed tomography and macroscopic data

    SciTech Connect (OSTI)

    Gupta, A.; Moridis, G.J.; Kneafsey, T.J.; Sloan, Jr., E.D.

    2009-08-15T23:59:59.000Z

    The numerical simulator TOUGH+HYDRATE (T+H) was used to predict the transient pure methane hydrate (no sediment) dissociation data. X-ray computed tomography (CT) was used to visualize the methane hydrate formation and dissociation processes. A methane hydrate sample was formed from granular ice in a cylindrical vessel, and slow depressurization combined with thermal stimulation was applied to dissociate the hydrate sample. CT images showed that the water produced from the hydrate dissociation accumulated at the bottom of the vessel and increased the hydrate dissociation rate there. CT images were obtained during hydrate dissociation to confirm the radial dissociation of the hydrate sample. This radial dissociation process has implications for dissociation of hydrates in pipelines, suggesting lower dissociation times than for longitudinal dissociation. These observations were also confirmed by the numerical simulator predictions, which were in good agreement with the measured thermal data during hydrate dissociation. System pressure and sample temperature measured at the sample center followed the CH{sub 4} hydrate L{sub w}+H+V equilibrium line during hydrate dissociation. The predicted cumulative methane gas production was within 5% of the measured data. Thus, this study validated our simulation approach and assumptions, which include stationary pure methane hydrate-skeleton, equilibrium hydrate-dissociation and heat- and mass-transfer in predicting hydrate dissociation in the absence of sediments. It should be noted that the application of T+H for the pure methane hydrate system (no sediment) is outside the general applicability limits of T+H.

  14. Methane Hydrate Program

    Office of Environmental Management (EM)

    Biofilms in Fracture-Dominated Sediment that Anaerobically Oxidize Methane. Applied and Environmental Microbiology, 77, 7 pp. Brunner, C., Ingram, W., Meyers, S.,...

  15. Solubility of Hematite Revisited: Effects of Hydration

    E-Print Network [OSTI]

    Burgos, William

    immediately after synthesis, but [Fe(III)diss] increased with hydration time to be consistent with the predicted solubility of goethite or hydrous ferric oxide (HFO), hydrated analogues of hematite. X an equilibrium with goethite or HFO. This is the first experimental confirmation that the interfacial hydration

  16. High-pressure gas hydrates 

    E-Print Network [OSTI]

    Loveday, J. S.; Nelmes, R. J.

    It has long been known that crystalline hydrates are formed by many simple gases that do not interact strongly with water, and in most cases the gas molecules or atoms occupy 'cages' formed by a framework of water molecules. The majority...

  17. Handbook of gas hydrate properties and occurrence

    SciTech Connect (OSTI)

    Kuustraa, V.A.; Hammershaimb, E.C.

    1983-12-01T23:59:59.000Z

    This handbook provides data on the resource potential of naturally occurring hydrates, the properties that are needed to evaluate their recovery, and their production potential. The first two chapters give data on the naturally occurring hydrate potential by reviewing published resource estimates and the known and inferred occurrences. The third and fourth chapters review the physical and thermodynamic properties of hydrates, respectively. The thermodynamic properties of hydrates that are discussed include dissociation energies and a simplified method to calculate them; phase diagrams for simple and multi-component gases; the thermal conductivity; and the kinetics of hydrate dissociation. The final chapter evaluates the net energy balance of recovering hydrates and shows that a substantial positive energy balance can theoretically be achieved. The Appendices of the Handbook summarize physical and thermodynamic properties of gases, liquids and solids that can be used in designing and evaluating recovery processes of hydrates. 158 references, 67 figures, 47 tables.

  18. Laboratory measurements on core-scale sediment/hydrate samples to predice reservoir behavior

    E-Print Network [OSTI]

    Kneafsey, Timothy J.; Seol, Yongkoo; Moridis, George J.; Tomutsa, Liviu; Freifeld, Barry M.

    2008-01-01T23:59:59.000Z

    International Conference on Gas Hydrates, Trondheim, Norway,coring of near-surface gas hydrate sediments on HydrateInternational Conference on Gas Hydrates, Trondheim, Norway,

  19. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    Collett, T.S. , 1993. Natural gas hydrates of the Prudhoe2008. Mechanical Properties of Natural Gas Hydrate Bearinggas hydrate reservoir. Natural Gas Hydrate: In Oceanic and

  20. Presentations from the March 27th - 28th Methane Hydrates Advisory...

    Office of Environmental Management (EM)

    from the March 27th - 28th Methane Hydrates Advisory Committee Meeting International Gas Hydrate Research DOE's Natural Gas Hydrates Program Gas Hydrates as a Geohazard: What...

  1. Laboratory measurements on core-scale sediment/hydrate samples to predice reservoir behavior

    E-Print Network [OSTI]

    Kneafsey, Timothy J.; Seol, Yongkoo; Moridis, George J.; Tomutsa, Liviu; Freifeld, Barry M.

    2008-01-01T23:59:59.000Z

    International Conference on Gas Hydrates, Yokohama, May 19-International Conference on Gas Hydrates, Trondheim, Norway,coring of near-surface gas hydrate sediments on Hydrate

  2. CX-010983: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Mechanisms for Methane Transport and Hydrate Accumulation in Coarse-Grained Sediments CX(s) Applied: A9 Date: 09/13/2013 Location(s): New York Offices(s): National Energy Technology Laboratory

  3. CX-010982: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Mechanisms for Methane Transport and Hydrate Accumulation in Coarse-Grained Sediments CX(s) Applied: A9 Date: 09/13/2013 Location(s): Ohio Offices(s): National Energy Technology Laboratory

  4. CX-009327: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Gas Hydrate Dynamics on the Alaskan Beaufort Continental Slope: Modeling and Field Characterization CX(s) Applied: A9 Date: 09/27/2012 Location(s): Texas Offices(s): National Energy Technology Laboratory

  5. CX-009329: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Gas Hydrate Dynamics on the Alaskan Beaufort Continental Slope: Modeling and Field Characterization CX(s) Applied: A9, B3.16 Date: 09/27/2012 Location(s): Alaska Offices(s): National Energy Technology Laboratory

  6. CX-008513: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Hydrate Growth Modeling in the Laboratory CX(s) Applied: A9, A11, B3.6 Date: 07/13/2012 Location(s): Oklahoma Offices(s): National Energy Technology Laboratory

  7. CX-008512: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Hydrate Growth Modeling in the Laboratory CX(s) Applied: A9, B3.6 Date: 07/13/2012 Location(s): Colorado Offices(s): National Energy Technology Laboratory

  8. CX-010954: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Hydrate Evolution in Response to Ongoing Environmental Shifts CX(s) Applied: A9 Date: 09/17/2013 Location(s): Oregon Offices(s): National Energy Technology Laboratory

  9. CX-011282: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Mechanisms for Methane Transport and Hydrate Accumulation in Coarse-Grained Sediments CX(s) Applied: A9 Date: 09/26/2013 Location(s): Texas Offices(s): National Energy Technology Laboratory

  10. CX-007923: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Conference Support for 2nd Gordon Research Conference on Natural Gas Hydrates CX(s) Applied: A1 Date: 02/23/2012 Location(s): California Offices(s): National Energy Technology Laboratory

  11. CX-008917: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Application of Crunch-Flow to Constrain Present and Past Carbon Fluxes at Gas-Hydrate Bearing Sites CX(s) Applied: A9 Date: 08/29/2012 Location(s): Oregon Offices(s): National Energy Technology Laboratory

  12. CX-009266: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Controls on Methane Expulsion During Melting of Natural Gas Hydrate Systems CX(s) Applied: A9 Date: 09/11/2012 Location(s): Texas Offices(s): National Energy Technology Laboratory

  13. CX-009264: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Controls on Methane Expulsion During Melting of Natural Gas Hydrate Systems CX(s) Applied: B3.6 Date: 09/12/2012 Location(s): California Offices(s): National Energy Technology Laboratory

  14. CX-012427: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Alaska Hydrate Production Testing: Test Site Selection and Characterization CX(s) Applied: A1, A9Date: 41879 Location(s): ColoradoOffices(s): National Energy Technology Laboratory

  15. Multiple stage multiple filter hydrate store

    DOE Patents [OSTI]

    Bjorkman, H.K. Jr.

    1983-05-31T23:59:59.000Z

    An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means for separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means. 7 figs.

  16. Multiple stage multiple filter hydrate store

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K. (Birmingham, MI)

    1983-05-31T23:59:59.000Z

    An improved hydrate store for a metal halogen battery system is disclosed which employs a multiple stage, multiple filter means or separating the halogen hydrate from the liquid used in forming the hydrate. The filter means is constructed in the form of three separate sections which combine to substantially cover the interior surface of the store container. Exit conduit means is provided in association with the filter means for transmitting liquid passing through the filter means to a hydrate former subsystem. The hydrate former subsystem combines the halogen gas generated during the charging of the battery system with the liquid to form the hydrate in association with the store. Relief valve means is interposed in the exit conduit means for controlling the operation of the separate sections of the filter means, such that the liquid flow through the exit conduit means from each of the separate sections is controlled in a predetermined sequence. The three separate sections of the filter means operate in three discrete stages to provide a substantially uniform liquid flow to the hydrate former subsystem during the charging of the battery system. The separation of the liquid from the hydrate causes an increase in the density of the hydrate by concentrating the hydrate along the filter means.

  17. Gas hydrate cool storage system

    DOE Patents [OSTI]

    Ternes, Mark P. (Knoxville, TN); Kedl, Robert J. (Oak Ridge, TN)

    1985-01-01T23:59:59.000Z

    This invention is a process for formation of a gas hydrate to be used as a cool storage medium using a refrigerant in water. Mixing of the immiscible refrigerant and water is effected by addition of a surfactant and agitation. The difficult problem of subcooling during the process is overcome by using the surfactant and agitation and performance of the process significantly improves and approaches ideal.

  18. Noble gases and radiocarbon in natural gas hydrates Gisela Winckler

    E-Print Network [OSTI]

    Aeschbach-Hertig, Werner

    Noble gases and radiocarbon in natural gas hydrates Gisela Winckler Lamont-Doherty Earth 2001; published 24 May 2002. [1] In samples of pure natural gas hydrates from Hydrate Ridge, Cascadia ones preferentially incorporated into the gas hydrate structure. The hydrate methane is devoid of 14 C

  19. Hydrate-phobic surfaces: fundamental studies in clathrate hydrate adhesion reduction

    E-Print Network [OSTI]

    Smith, J. David

    Clathrate hydrate formation and subsequent plugging of deep-sea oil and gas pipelines represent a significant bottleneck for deep-sea oil and gas operations. Current methods for hydrate mitigation are expensive and energy ...

  20. Development of Alaskan gas hydrate resources

    SciTech Connect (OSTI)

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01T23:59:59.000Z

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  1. Temperature effect on the small-to-large crossover length-scale of hydrophobic hydration

    E-Print Network [OSTI]

    Yuri S. Djikaev; Eli Ruckenstein

    2013-07-29T23:59:59.000Z

    The thermodynamics of hydration changes gradually from entropic for small solutes to enthalpic for large ones. The small-to-large crossover lengthscale of hydrophobic hydration depends on the thermodynamic conditions of the solvent such as temperature, pressure, presence of additives, etc... We attempt to shed some light on the temperature dependence of the crossover lengthscale by using a probabilistic approach to water hydrogen bonding that allows one to obtain an analytic expression for the number of bonds per water molecule as a function of both its distance to a solute and solute radius. Incorporating that approach into the density functional theory, one can examine the solute size effects on its hydration over the entire small-to-large lengthscale range at different temperatures. Knowing the dependence of the hydration free energy on temperature and solute size, one can obtain its enthalpic and entropic contributions as functions of temperature and solute size. These function can provide interesting insight into the temperature dependence of the crossover lengthscale of hydrophobic hydration. The model was applied to the hydration of spherical particles of various radii in water in the temperature range from T=293.15 K to T=333.15 K. The model predictions for the temperature dependence of the hydration free energy of small hydrophobes are consistent with the experimental and simulational data. Three alternative definitions for the small-to-large crossover length-scale of hydrophobic hydration are proposed, and their temperature dependence is obtained. Depending on the definition and temperature, the small-to-large crossover in the hydration mechanism is predicted to occur for hydrophobes of radii from one to several nanometers. Independent of its definition, the crossover length-scale is predicted to decrease with increasing temperature.

  2. Physical Properties of Gas Hydrates: A Review

    SciTech Connect (OSTI)

    Gabitto, Jorge [Prairie View A& M University; Tsouris, Costas [ORNL

    2010-01-01T23:59:59.000Z

    Methane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately 1016?m3 of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detected by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed.

  3. Desalination utilizing clathrate hydrates (LDRD final report).

    SciTech Connect (OSTI)

    Simmons, Blake Alexander; Bradshaw, Robert W.; Dedrick, Daniel E.; Cygan, Randall Timothy (Sandia National Laboratories, Albuquerque, NM); Greathouse, Jeffery A. (Sandia National Laboratories, Albuquerque, NM); Majzoub, Eric H. (University of Missouri, Columbia, MO)

    2008-01-01T23:59:59.000Z

    Advances are reported in several aspects of clathrate hydrate desalination fundamentals necessary to develop an economical means to produce municipal quantities of potable water from seawater or brackish feedstock. These aspects include the following, (1) advances in defining the most promising systems design based on new types of hydrate guest molecules, (2) selection of optimal multi-phase reactors and separation arrangements, and, (3) applicability of an inert heat exchange fluid to moderate hydrate growth, control the morphology of the solid hydrate material formed, and facilitate separation of hydrate solids from concentrated brine. The rate of R141b hydrate formation was determined and found to depend only on the degree of supercooling. The rate of R141b hydrate formation in the presence of a heat exchange fluid depended on the degree of supercooling according to the same rate equation as pure R141b with secondary dependence on salinity. Experiments demonstrated that a perfluorocarbon heat exchange fluid assisted separation of R141b hydrates from brine. Preliminary experiments using the guest species, difluoromethane, showed that hydrate formation rates were substantial at temperatures up to at least 12 C and demonstrated partial separation of water from brine. We present a detailed molecular picture of the structure and dynamics of R141b guest molecules within water cages, obtained from ab initio calculations, molecular dynamics simulations, and Raman spectroscopy. Density functional theory calculations were used to provide an energetic and molecular orbital description of R141b stability in both large and small cages in a structure II hydrate. Additionally, the hydrate of an isomer, 1,2-dichloro-1-fluoroethane, does not form at ambient conditions because of extensive overlap of electron density between guest and host. Classical molecular dynamics simulations and laboratory trials support the results for the isomer hydrate. Molecular dynamics simulations show that R141b hydrate is stable at temperatures up to 265K, while the isomer hydrate is only stable up to 150K. Despite hydrogen bonding between guest and host, R141b molecules rotated freely within the water cage. The Raman spectrum of R141b in both the pure and hydrate phases was also compared with vibrational analysis from both computational methods. In particular, the frequency of the C-Cl stretch mode (585 cm{sup -1}) undergoes a shift to higher frequency in the hydrate phase. Raman spectra also indicate that this peak undergoes splitting and intensity variation as the temperature is decreased from 4 C to -4 C.

  4. Effects of Antiagglomerants on the Interactions between Hydrate Particles

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    InterScience (www.interscience.wiley.com). Hydrate inbibition in natural gas production­574, 2008 Keywords: gas hydrates, antiagglomeration, capillary force, steric repulsion, natural gas production Introduction The undesirable formation of gas hydrates in natural gas pipelines

  5. Methane hydrate research at NETL: Research to make methane production from hydrates a reality

    SciTech Connect (OSTI)

    Taylor, C.E.; Link, D.D.; English, N.

    2007-03-01T23:59:59.000Z

    Research is underway at NETL to understand the physical properties of methane hydrates. Five key areas of research that need further investigation have been identified. These five areas, i.e. thermal properties of hydrates in sediments, kinetics of natural hydrate dissociation, hysteresis effects, permeability of sediments to gas flow and capillary pressures within sediments, and hydrate distribution at porous scale, are important to the production models that will be used for producing methane from hydrate deposits. NETL is using both laboratory experiments and computational modeling to address these five key areas. The laboratory and computational research reinforce each other by providing feedback. The laboratory results are used in the computational models and the results from the computational modeling is used to help direct future laboratory research. The data generated at NETL will be used to help fulfill The National Methane Hydrate R&D Program of a “long-term supply of natural gas by developing the knowledge and technology base to allow commercial production of methane from domestic hydrate deposits by the year 2015” as outlined on the NETL Website [NETL Website, 2005. http://www.netl.doe.gov/scngo/Natural%20Gas/hydrates/index.html]. Laboratory research is accomplished in one of the numerous high-pressure hydrate cells available ranging in size from 0.15 mL to 15 L in volume. A dedicated high-pressure view cell within the Raman spectrometer allows for monitoring the formation and dissociation of hydrates. Thermal conductivity of hydrates (synthetic and natural) at a certain temperature and pressure is performed in a NETL-designed cell. Computational modeling studies are investigating the kinetics of hydrate formation and dissociation, modeling methane hydrate reservoirs, molecular dynamics simulations of hydrate formation, dissociation, and thermal properties, and Monte Carlo simulations of hydrate formation and dissociation.

  6. Estimating the amount of gas hydrate and free gas from marine seismic data

    SciTech Connect (OSTI)

    Ecker, C.; Dvorkin, J.; Nur, A.M.

    2000-04-01T23:59:59.000Z

    Marine seismic data and well-log measurements at the Blake Ridge offshore South Carolina show that prominent seismic bottom-simulating reflectors (BSRs) are caused by sediment layers with gas hydrate overlying sediments with free gas. The authors apply a theoretical rock-physics model to 2-D Blake Ridge marine seismic data to determine gas-hydrate and free-gas saturation. High-porosity marine sediment is modeled as a granular system where the elastic wave velocities are linked to porosity; effective pressure; mineralogy; elastic properties of the pore-filling material; and water, gas, and gas-hydrate saturation of the pore space. To apply this model to seismic data, the authors first obtain interval velocity using stacking velocity analysis. Next, all input parameters to the rock-physics model, except porosity and water, gas and gas hydrate saturation, are estimated from geologic information. To estimate porosity and saturation from interval velocity, they first assume that the entire sediment does not contain gas hydrate or free gas. Then they use the rock-physics model to calculate porosity directly from the interval velocity. Such porosity profiles appear to have anomalies where gas hydrate and free gas are present (as compared to typical profiles expected and obtained in sediment without gas hydrate of gas). Porosity is underestimated in the hydrate region and is overestimated in the free-gas region. The authors calculate the porosity residuals by subtracting a typical porosity profile (without gas hydrate and gas) from that with anomalies. Next they use the rock-physics model to eliminate these anomalies by introducing gas-hydrate of gas saturation. As a result, they obtain the desired 2-D saturation map. The maximum gas-hydrate saturation thus obtained is between 13% and 18% of the pore space (depending on the version of the model used). These saturation values are consistent with those measured in the Blake Ridge wells (away from the seismic line), which are about 12%. Free-gas saturation varies between 1% and 2%. The saturation estimates are extremely sensitive to the input velocity values. Therefore, accurate velocity determination is crucial for correct reservoir characterization.

  7. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical CO2. Microstructural Response of Variably Hydrated Ca-Rich Montmorillonite to Supercritical...

  8. aluminate cements hydration: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    early stage hydration of different classes of oilwell cement Bentz, Dale P. 5 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  9. Stepwise hydration of the cyanide anion: A temperature-controlled...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stepwise hydration of the cyanide anion: A temperature-controlled photoelectron spectroscopy and ab initio computational study Stepwise hydration of the cyanide anion: A...

  10. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the revolutionary and new Arctic Drilling Platform in search of gas hydrate and free gas accumulations at depths of approximately 1200 to 2500 ft MD. A secondary objective was the gas-charged sands of the uppermost Campanian interval at approximately 3000 ft. Summary results of geophysical analysis of the well are presented in this report.

  11. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in the project reports.

  12. Overview on Hydrate Coring, Handling and Analysis

    SciTech Connect (OSTI)

    Jon Burger; Deepak Gupta; Patrick Jacobs; John Shillinglaw

    2003-06-30T23:59:59.000Z

    Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Worldwide, gas hydrate is estimated to hold about 1016 kg of organic carbon in the form of methane (Kvenvolden et al., 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In June 2002, Westport Technology Center was requested by the Department of Energy (DOE) to prepare a ''Best Practices Manual on Gas Hydrate Coring, Handling and Analysis'' under Award No. DE-FC26-02NT41327. The scope of the task was specifically targeted for coring sediments with hydrates in Alaska, the Gulf of Mexico (GOM) and from the present Ocean Drilling Program (ODP) drillship. The specific subjects under this scope were defined in 3 stages as follows: Stage 1: Collect information on coring sediments with hydrates, core handling, core preservation, sample transportation, analysis of the core, and long term preservation. Stage 2: Provide copies of the first draft to a list of experts and stakeholders designated by DOE. Stage 3: Produce a second draft of the manual with benefit of input from external review for delivery. The manual provides an overview of existing information available in the published literature and reports on coring, analysis, preservation and transport of gas hydrates for laboratory analysis as of June 2003. The manual was delivered as draft version 3 to the DOE Project Manager for distribution in July 2003. This Final Report is provided for records purposes.

  13. Diffusion of CO2 During Hydrate Formation and Dissolution

    SciTech Connect (OSTI)

    Franklin M. Orr, Jr.

    2002-08-20T23:59:59.000Z

    Experiments were performed to measure the rate of diffusion of CO2 through hydrate films. Hydrate films were created in a capillary tube, and the growth of the hydrate film was measured. Difficulties were encountered in creating hydrate repeatedly, and some non-uniform growth of the films was observed. Sufficient observations were obtained to demonstrate that hydrate growth occurs preferentially on the hydrate/water side of the interface, rather than at the hydrate/CO2 interface. Diffusion coefficients were estimated from observations of the rate of growth of the hydrate film along with estimates of the solubility of CO2 in water and of the concentration gradient across the hydrate layer. The experimental observations indicate that hydrate formation occurs much more rapidly at the hydrate water interface than at the hydrate/CO2 interface. Any growth of hydrate at the CO2/hydrate interface was too slow to be observed at the time scale of the experiments. That observation is consistent with the idea that CO2 can move more easily through the hydrate, presumably by hopping between hydrate cages, than water can move through the hydrate, presumably by lattice hopping. Estimated diffusion coefficients were in the range 1-3E-06 cm2/sec. Those values are about an order of magnitude lower than the diffusion coefficient for CO2 in liquid water, but four orders of magnitude larger than the value for diffusion of CO2 in a solid. The rate of diffusion through the hydrate controls both the creation of new hydrate at the hydrate/water interface and the rate at which CO2 dissolves in the liquid water and diffuses away from the hydrate layer. Formation of a hydrate layer reduces the rate at which CO2 dissolves in liquid water.

  14. Gas Hydrate Storage of Natural Gas

    SciTech Connect (OSTI)

    Rudy Rogers; John Etheridge

    2006-03-31T23:59:59.000Z

    Environmental and economic benefits could accrue from a safe, above-ground, natural-gas storage process allowing electric power plants to utilize natural gas for peak load demands; numerous other applications of a gas storage process exist. A laboratory study conducted in 1999 to determine the feasibility of a gas-hydrates storage process looked promising. The subsequent scale-up of the process was designed to preserve important features of the laboratory apparatus: (1) symmetry of hydrate accumulation, (2) favorable surface area to volume ratio, (3) heat exchanger surfaces serving as hydrate adsorption surfaces, (4) refrigeration system to remove heat liberated from bulk hydrate formation, (5) rapid hydrate formation in a non-stirred system, (6) hydrate self-packing, and (7) heat-exchanger/adsorption plates serving dual purposes to add or extract energy for hydrate formation or decomposition. The hydrate formation/storage/decomposition Proof-of-Concept (POC) pressure vessel and supporting equipment were designed, constructed, and tested. This final report details the design of the scaled POC gas-hydrate storage process, some comments on its fabrication and installation, checkout of the equipment, procedures for conducting the experimental tests, and the test results. The design, construction, and installation of the equipment were on budget target, as was the tests that were subsequently conducted. The budget proposed was met. The primary goal of storing 5000-scf of natural gas in the gas hydrates was exceeded in the final test, as 5289-scf of gas storage was achieved in 54.33 hours. After this 54.33-hour period, as pressure in the formation vessel declined, additional gas went into the hydrates until equilibrium pressure/temperature was reached, so that ultimately more than the 5289-scf storage was achieved. The time required to store the 5000-scf (48.1 hours of operating time) was longer than designed. The lower gas hydrate formation rate is attributed to a lower heat transfer rate in the internal heat exchanger than was designed. It is believed that the fins on the heat-exchanger tubes did not make proper contact with the tubes transporting the chilled glycol, and pairs of fins were too close for interior areas of fins to serve as hydrate collection sites. A correction of the fabrication fault in the heat exchanger fin attachments could be easily made to provide faster formation rates. The storage success with the POC process provides valuable information for making the process an economically viable process for safe, aboveground natural-gas storage.

  15. Methane Recovery from Hydrate-bearing Sediments

    SciTech Connect (OSTI)

    J. Carlos Santamarina; Costas Tsouris

    2011-04-30T23:59:59.000Z

    Gas hydrates are crystalline compounds made of gas and water molecules. Methane hydrates are found in marine sediments and permafrost regions; extensive amounts of methane are trapped in the form of hydrates. Methane hydrate can be an energy resource, contribute to global warming, or cause seafloor instability. This study placed emphasis on gas recovery from hydrate bearing sediments and related phenomena. The unique behavior of hydrate-bearing sediments required the development of special research tools, including new numerical algorithms (tube- and pore-network models) and experimental devices (high pressure chambers and micromodels). Therefore, the research methodology combined experimental studies, particle-scale numerical simulations, and macro-scale analyses of coupled processes. Research conducted as part of this project started with hydrate formation in sediment pores and extended to production methods and emergent phenomena. In particular, the scope of the work addressed: (1) hydrate formation and growth in pores, the assessment of formation rate, tensile/adhesive strength and their impact on sediment-scale properties, including volume change during hydrate formation and dissociation; (2) the effect of physical properties such as gas solubility, salinity, pore size, and mixed gas conditions on hydrate formation and dissociation, and it implications such as oscillatory transient hydrate formation, dissolution within the hydrate stability field, initial hydrate lens formation, and phase boundary changes in real field situations; (3) fluid conductivity in relation to pore size distribution and spatial correlation and the emergence of phenomena such as flow focusing; (4) mixed fluid flow, with special emphasis on differences between invading gas and nucleating gas, implications on relative gas conductivity for reservoir simulations, and gas recovery efficiency; (5) identification of advantages and limitations in different gas production strategies with emphasis; (6) detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2; (7) the relevance of fines in otherwise clean sand sediments on gas recovery and related phenomena such as fines migration and clogging, vuggy structure formation, and gas-driven fracture formation during gas production by depressurization.

  16. Detection and Production of Methane Hydrate

    SciTech Connect (OSTI)

    George Hirasaki; Walter Chapman; Gerald Dickens; Colin Zelt; Brandon Dugan; Kishore Mohanty; Priyank Jaiswal

    2011-12-31T23:59:59.000Z

    This project seeks to understand regional differences in gas hydrate systems from the perspective of as an energy resource, geohazard, and long-term climate influence. Specifically, the effort will: (1) collect data and conceptual models that targets causes of gas hydrate variance, (2) construct numerical models that explain and predict regional-scale gas hydrate differences in 2-dimensions with minimal 'free parameters', (3) simulate hydrocarbon production from various gas hydrate systems to establish promising resource characteristics, (4) perturb different gas hydrate systems to assess potential impacts of hot fluids on seafloor stability and well stability, and (5) develop geophysical approaches that enable remote quantification of gas hydrate heterogeneities so that they can be characterized with minimal costly drilling. Our integrated program takes advantage of the fact that we have a close working team comprised of experts in distinct disciplines. The expected outcomes of this project are improved exploration and production technology for production of natural gas from methane hydrates and improved safety through understanding of seafloor and well bore stability in the presence of hydrates. The scope of this project was to more fully characterize, understand, and appreciate fundamental differences in the amount and distribution of gas hydrate and how this would affect the production potential of a hydrate accumulation in the marine environment. The effort combines existing information from locations in the ocean that are dominated by low permeability sediments with small amounts of high permeability sediments, one permafrost location where extensive hydrates exist in reservoir quality rocks and other locations deemed by mutual agreement of DOE and Rice to be appropriate. The initial ocean locations were Blake Ridge, Hydrate Ridge, Peru Margin and GOM. The permafrost location was Mallik. Although the ultimate goal of the project was to understand processes that control production potential of hydrates in marine settings, Mallik was included because of the extensive data collected in a producible hydrate accumulation. To date, such a location had not been studied in the oceanic environment. The project worked closely with ongoing projects (e.g. GOM JIP and offshore India) that are actively investigating potentially economic hydrate accumulations in marine settings. The overall approach was fivefold: (1) collect key data concerning hydrocarbon fluxes which is currently missing at all locations to be included in the study, (2) use this and existing data to build numerical models that can explain gas hydrate variance at all four locations, (3) simulate how natural gas could be produced from each location with different production strategies, (4) collect new sediment property data at these locations that are required for constraining fluxes, production simulations and assessing sediment stability, and (5) develop a method for remotely quantifying heterogeneities in gas hydrate and free gas distributions. While we generally restricted our efforts to the locations where key parameters can be measured or constrained, our ultimate aim was to make our efforts universally applicable to any hydrate accumulation.

  17. Gas Hydrates Research Programs: An International Review

    SciTech Connect (OSTI)

    Jorge Gabitto; Maria Barrufet

    2009-12-09T23:59:59.000Z

    Gas hydrates sediments have the potential of providing a huge amount of natural gas for human use. Hydrate sediments have been found in many different regions where the required temperature and pressure conditions have been satisfied. Resource exploitation is related to the safe dissociation of the gas hydrate sediments. Basic depressurization techniques and thermal stimulation processes have been tried in pilot efforts to exploit the resource. There is a growing interest in gas hydrates all over the world due to the inevitable decline of oil and gas reserves. Many different countries are interested in this valuable resource. Unsurprisingly, developed countries with limited energy resources have taken the lead in worldwide gas hydrates research and exploration. The goal of this research project is to collect information in order to record and evaluate the relative strengths and goals of the different gas hydrates programs throughout the world. A thorough literature search about gas hydrates research activities has been conducted. The main participants in the research effort have been identified and summaries of their past and present activities reported. An evaluation section discussing present and future research activities has also been included.

  18. The hydration mechanism of ketene: 15 years later

    E-Print Network [OSTI]

    Nguyen, Minh Tho

    the self-consistent reaction field method (SCRF) and the polarizable continuum model (PCM). The hydration

  19. IMPROVEMENT OF METHANE STORAGE IN ACTIVATED CARBON USING METHANE HYDRATE

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    it to a gas hydrate formation. In fact, the gas hydrate formation in the remaining free porosity after manuscript, published in "Fifth International Conference on Gas Hydrates (ICGH 5),, Tromdheim : Norway (2005IMPROVEMENT OF METHANE STORAGE IN ACTIVATED CARBON USING METHANE HYDRATE M.L. Zanota(1) , L. Perier

  20. Department of Energy Advance Methane Hydrates Science and Technology Projects

    Broader source: Energy.gov [DOE]

    Descriptions for Energy Department Methane Hydrates Science and Technology Projects, August 31, 2012

  1. Dipolar response of hydrated proteins

    E-Print Network [OSTI]

    Dmitry V. Matyushov

    2011-08-12T23:59:59.000Z

    The paper presents an analytical theory and numerical simulations of the dipolar response of hydrated proteins. The effective dielectric constant of the solvated protein, representing the average dipole moment induced at the protein by a uniform external field, shows a remarkable variation among the proteins studied by numerical simulations. It changes from 0.5 for ubiquitin to 640 for cytochrome c. The former value implies a negative dipolar susceptibility of ubiquitin, that is a dia-electric dipolar response and negative dielectrophoresis. It means that a protein carrying an average dipole of ~240 D is expected to repel from the region of a stronger electric field. This outcome is the result of a negative cross-correlation between the protein and water dipoles, compensating for the positive variance of the protein dipole in the overall dipolar susceptibility. This phenomenon can be characterized as overscreening of protein's dipole by the hydration shell. In contrast to the neutral ubiquitin, charged proteins studied here show para-electric dipolar response and positive dielectrophoresis. The protein-water dipolar cross-correlations are long-ranged, extending approximately 2 nm from the protein surface into the bulk. The analysis of numerical simulations suggests that the polarization of the protein-water interface is strongly affected by the distribution of the protein surface charge. This component of the protein dipolar response gains in importance for high frequencies, above the protein Debye peak, when the response of the protein dipole becomes dynamically arrested. The interface response found in simulations suggests a possibility of a positive increment of the high-frequency dielectric constant of the solution compared to the dielectric constant of the solvent, in support of the observed THz absorbance of protein solutions.

  2. Nanomechanical properties of hydrated organic thin films

    E-Print Network [OSTI]

    Choi, Jae Hyeok

    2007-01-01T23:59:59.000Z

    Hydrated organic thin films are biological or synthetic molecularly thin coatings which impart a particular functionality to an underlying substrate and which have discrete water molecules associated with them. Such films ...

  3. ConocoPhillips Gas Hydrate Production Test

    SciTech Connect (OSTI)

    Schoderbek, David; Farrell, Helen; Howard, James; Raterman, Kevin; Silpngarmlert, Suntichai; Martin, Kenneth; Smith, Bruce; Klein, Perry

    2013-06-30T23:59:59.000Z

    Work began on the ConocoPhillips Gas Hydrates Production Test (DOE award number DE-NT0006553) on October 1, 2008. This final report summarizes the entire project from January 1, 2011 to June 30, 2013.

  4. A realistic molecular model of cement hydrates

    E-Print Network [OSTI]

    Ulm, Franz-Josef

    Despite decades of studies of calcium-silicate-hydrate (C-S-H), the structurally complex binder phase of concrete, the interplay between chemical composition and density remains essentially unexplored. Together these ...

  5. MethaneHydrateRD_FC.indd

    Office of Environmental Management (EM)

    source of natural gas in 1983. The Methane Hydrate Research and Development Act of 2000 established DOE as the lead U.S. agency for R&D in this fi eld. Early phases of...

  6. Metal-Catalyzed Hydration of 2-Pyridyloxirane

    E-Print Network [OSTI]

    Hanzlik, Robert P.; Michaely, William J.

    1975-01-01T23:59:59.000Z

    In the presence of CuII the hydration of 2-pyridyloxiran is accelerated 18,000-fold, and its reaction with Cl–, Br–, and MeO– becomes 100% regiospecific for ?-attack....

  7. Hydrate Control for Gas Storage Operations

    SciTech Connect (OSTI)

    Jeffrey Savidge

    2008-10-31T23:59:59.000Z

    The overall objective of this project was to identify low cost hydrate control options to help mitigate and solve hydrate problems that occur in moderate and high pressure natural gas storage field operations. The study includes data on a number of flow configurations, fluids and control options that are common in natural gas storage field flow lines. The final phase of this work brings together data and experience from the hydrate flow test facility and multiple field and operator sources. It includes a compilation of basic information on operating conditions as well as candidate field separation options. Lastly the work is integrated with the work with the initial work to provide a comprehensive view of gas storage field hydrate control for field operations and storage field personnel.

  8. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Donn McGuire; Thomas Williams; Bjorn Paulsson; Alexander Goertz

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a drilling hazard by the oil and gas industry for years. Drilling engineers working in Russia, Canada and the USA have documented numerous problems, including drilling kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates as a potential energy source agree that the resource potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained from physical samples taken from actual hydrate-bearing rocks. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The project team drilled and continuously cored the Hot Ice No. 1 well on Anadarko-leased acreage beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and used for determining physical characteristics of hydrates and surrounding rock. After the well was logged, a 3D vertical seismic profile (VSP) was recorded to calibrate the shallow geologic section with seismic data and to investigate techniques to better resolve lateral subsurface variations of potential hydrate-bearing strata. Paulsson Geophysical Services, Inc. deployed their 80 level 3C clamped borehole seismic receiver array in the wellbore to record samples every 25 ft. Seismic vibrators were successively positioned at 1185 different surface positions in a circular pattern around the wellbore. This technique generated a 3D image of the subsurface. Correlations were generated of these seismic data with cores, logging, and other well data. Unfortunately, the Hot Ice No. 1 well did not encounter hydrates in the reservoir sands, although brine-saturated sands containing minor amounts of methane were encountered within the hydrate stability zone (HSZ). Synthetic seismograms created from well log data were in agreement with reflectivity data measured by the 3D VSP survey. Modeled synthetic seismograms indicated a detectable seismic response would be expected in the presence of hydrate-bearing sands. Such a response was detected in the 3D VSP data at locations up-dip to the west of the Hot Ice No. 1 wellbore. Results of this project suggest that the presence of hydrate-bearing strata may not be related as simply to HSZ thickness as previously thought. Geological complications of reservoir facies distribution within fluvial-deltaic environments will require sophisticated detection technologies to assess the locations of recoverable volumes of methane contained in hydrates. High-resolution surface seismic data and more rigorous well log data analysis offer the best near-term potential. The hydrate resource potential is huge, but better tools are needed to accurately assess their location, distribution and economic recoverability.

  9. Weakening of ice by magnesium perchlorate hydrate

    E-Print Network [OSTI]

    Lenferink, Hendrik J., 1985-

    2012-01-01T23:59:59.000Z

    I show that perchlorate hydrates, which have been indirectly detected at high Martian circumpolar latitudes by the Phoenix Mars Lander, have a dramatic effect upon the rheological behavior of polycrystalline water ice under ...

  10. Modeling of gas hydrates from first principles

    E-Print Network [OSTI]

    Cao, Zhitao, 1974-

    2002-01-01T23:59:59.000Z

    Ab initio calculations were used to determine the H20-CH4 potential energy surface (PES) accurately for use in modeling gas hydrates. Electron correlation was found to be treated accurately by the second-order Moller-Plesset ...

  11. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models and to research teams for developing future gas-hydrate projects. No gas hydrates were encountered in this well; however, a wealth of information was generated and has been documented by the project team. This Topical Report documents drilling and coring operations and other daily activities.

  12. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Steve Runyon; Mike Globe; Kent Newsham; Robert Kleinberg; Doug Griffin

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists planning hydrate exploration and development projects. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this and other project reports. This Topical Report contains details describing logging operations.

  13. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored a well (the Hot Ice No. 1) on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in the project reports. Documenting the results of this effort are key to extracting lessons learned and maximizing the industry's benefits for future hydrate exploitation.

  14. Thermal dissociation behavior and dissociation enthalpies of methane-carbon dioxide mixed hydrates

    E-Print Network [OSTI]

    Kwon, T.H.

    2012-01-01T23:59:59.000Z

    Dissociation heat of mixed-gas hydrate composed of methaneInternational Conference on Gas Hydrates (ICGH 2008), 2008,and specific heats of gas hydrates under submarine and

  15. The effect of reservoir heterogeneity on gas production from hydrate accumulations in the permafrost

    E-Print Network [OSTI]

    Reagan, M. T.

    2010-01-01T23:59:59.000Z

    Spatial distributions of gas and hydrate phase saturations (from the Mallik 2002 Gas Hydrate Production Research Wellsimulating the behavior of gas hydrates, Energy Conversion

  16. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    of Gas Price ($/Mscf) for Offshore Gas Hydrate StudyEvaluation of deepwater gas-hydrate systems. The Leadingfor Gas Production from Gas Hydrates Reservoirs. J. Canadian

  17. Physical property changes in hydrate-bearing sediment due to depressurization and subsequent repressurization

    E-Print Network [OSTI]

    Waite, W.F.

    2008-01-01T23:59:59.000Z

    distribution of water, gas and hydrate within a core and thecontaining natural and laboratory-formed gas hydrate, inNatural Gas Hydrate In Oceanic and Permafrost Environments,

  18. Methane Hydrate Dissociation by Depressurization in a Mount Elbert Sandstone Sample: Experimental Observations and Numerical Simulations

    E-Print Network [OSTI]

    Kneafsey, T.

    2012-01-01T23:59:59.000Z

    DOE-USGS Mount Elbert gas hydrate stratigraphic test well:International Conference on Gas Hydrates, Vancouver, BritishGeologic controls on gas hydrate occurrence in the Mount

  19. The dynamic response of oceanic hydrate deposits to ocean temperature change

    E-Print Network [OSTI]

    Reagan, Matthew T.

    2008-01-01T23:59:59.000Z

    of the fate of gas hydrates during transit through the oceanVA. (1998), Submarine Gas Hydrates. St. Petersburg. Gornitzgas reservoirs below gas-hydrate provinces, Nature, 427,

  20. Strategies for gas production from hydrate accumulations under various geologic conditions

    E-Print Network [OSTI]

    Moridis, G.; Collett, T.

    2003-01-01T23:59:59.000Z

    JNOC/GSC Mallik 2L- 38 Gas Hydrate Research Well, Mackenziedeposits. INTRODUCTION Gas hydrates are solid crystallinequantity of hydrocarbon gas hydrates range between 10 15 to

  1. Feasibility of monitoring gas hydrate production with time-lapse VSP

    E-Print Network [OSTI]

    Kowalsky, M.B.

    2010-01-01T23:59:59.000Z

    density of the aqueous, gas, and hydrate phases, which isfunction of the aqueous, gas and hydrate phase saturations;in Marine Sediments with Gas Hydrates: Effective Medium

  2. Gas production potential of disperse low-saturation hydrate accumulations in oceanic sediments

    E-Print Network [OSTI]

    Moridis, George J.; Sloan, E. Dendy

    2006-01-01T23:59:59.000Z

    EG. Formation of gas hydrates in natural gas transmissiongeology of natural gas hydrates. Amsterdam: Springer-Verlag;Soloviev, VA. Submarine gas hydrates. St. Petersburg;1998.

  3. The effect of reservoir heterogeneity on gas production from hydrate accumulations in the permafrost

    E-Print Network [OSTI]

    Reagan, M. T.

    2010-01-01T23:59:59.000Z

    Spatial distributions of gas and hydrate phase saturations (Team, 2008, Investigation of gas hydrate bearing sandstoneInternational Conference on Gas Hydrates, July 6-10, 2008,

  4. Study of the Natural Gas Hydrate 'Trap Zone' and the Methane Hydrate Potential in the Sverdrup Basin, Canada

    SciTech Connect (OSTI)

    Majorowicz, J. A. [Northern Geothermal Consult. (Canada)], E-mail: majorowi@show.ca; Hannigan, P. K.; Osadetz, K. G. [Geological Survey of Canada, Calgary (Canada)

    2002-06-15T23:59:59.000Z

    The methane hydrate stability zone beneath Sverdrup Basin has developed to a depth of 2 km underneath the Canadian Arctic Islands and 1 km below sea level under the deepest part of the inter-island sea channels. It is not, however, a continuous zone. Methane hydrates are detected in this zone, but the gas hydrate/free gas contact occurs rarely. Interpretation of well logs indicate that methane hydrate occurs within the methane stability zone in 57 of 150 analyzed wells. Fourteen wells show the methane hydrate/free gas contact. Analysis of the distribution of methane hydrate and hydrate/gas contact occurrences with respect to the present methane hydrate stability zone indicate that, in most instances, the detected methane hydrate occurs well above the base of methane hydrate stability. This relationship suggests that these methane hydrates were formed in shallower strata than expected with respect to the present hydrate stability zone from methane gases which migrated upward into hydrate trap zones. Presently, only a small proportion of gas hydrate occurrences occur in close proximity to the base of predicted methane hydrate stability. The association of the majority of detected hydrates with deeply buried hydrocarbon discoveries, mostly conventional natural gas accumulations, or mapped seismic closures, some of which are dry, located in structures in western and central Sverdrup Basin, indicate the concurring relationship of hydrate occurrence with areas of high heat flow. Either present-day or paleo-high heat flows are relevant. Twenty-three hydrate occurrences coincide directly with underlying conventional hydrocarbon accumulations. Other gas hydrate occurrences are associated with structures filled with water with evidence of precursor hydrocarbons that were lost because of upward leakage.

  5. Simulation of methane production in a laboratory-scale reactor containing hydrate-bearing porous medium

    SciTech Connect (OSTI)

    Gamwo, I.K.; Myshakin, E.M.; Zhang, Wu; Warzinski, R.P.

    2008-01-01T23:59:59.000Z

    Production of methane, induced by depressurization of hydrate sediment in a reactor, was investigated by numerical simulations using a computational fluid dynamics code TOUGH+/Hydrate. The methane production rates were computed at well-pressure drops of 4.2, 14.7, and 29.5 MPa and at a reactor temperature of 21 0C. The predicted behavior of methane production from the reactor is consistent with field-scale simulations and observations. The production rate increases with pressure drop at the well. Evolution patterns of gas and hydrate distributions are similar to those obtained in field-scale simulations. These preliminary results clearly indicate that numerical simulators can be applied to laboratory-scale reactors to anticipate scenarios observed in field experiments.

  6. Controls on Gas Hydrate Formation and Dissociation

    SciTech Connect (OSTI)

    Miriam Kastner; Ian MacDonald

    2006-03-03T23:59:59.000Z

    The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane supersaturated, thus bubble plumes form. The subsurface hydrology exhibits both up-flow and down-flow of fluid at rates that range between 0.5 to 214 cm/yr and 2-162 cm/yr, respectively. The fluid flow system at the mound and background sites are coupled having opposite polarities that oscillate episodically between 14 days to {approx}4 months. Stability calculations suggest that despite bottom water temperature fluctuations, of up to {approx}3 C, the Bush Hill gas hydrate mound is presently stable, as also corroborated by the time-lapse video camera images that did not detect change in the gas hydrate mound. As long as methane (and other hydrocarbon) continues advecting at the observed rates the mound would remain stable. The {_}{sup 13}C-DIC data suggest that crude oil instead of methane serves as the primary electron-donor and metabolic substrate for anaerobic sulfate reduction. The oil-dominated environment at Bush Hill shields some of the methane bubbles from being oxidized both anaerobically in the sediment and aerobically in the water column. Consequently, the methane flux across the seafloor is higher at Bush hill than at non-oil rich seafloor gas hydrate regions, such as at Hydrate Ridge, Cascadia. The methane flux across the ocean/atmosphere interface is as well higher. Modeling the methane flux across this interface at three bubble plumes provides values that range from 180-2000 {_}mol/m{sup 2} day; extrapolating it over the Gulf of Mexico basin utilizing satellite data is in progress.

  7. Complex admixtures of clathrate hydrates in a water desalination method

    DOE Patents [OSTI]

    Simmons, Blake A. (San Francisco, CA); Bradshaw, Robert W. (Livermore, CA); Dedrick, Daniel E. (Berkeley, CA); Anderson, David W. (Riverbank, CA)

    2009-07-14T23:59:59.000Z

    Disclosed is a method that achieves water desalination by utilizing and optimizing clathrate hydrate phenomena. Clathrate hydrates are crystalline compounds of gas and water that desalinate water by excluding salt molecules during crystallization. Contacting a hydrate forming gaseous species with water will spontaneously form hydrates at specific temperatures and pressures through the extraction of water molecules from the bulk phase followed by crystallite nucleation. Subsequent dissociation of pure hydrates yields fresh water and, if operated correctly, allows the hydrate-forming gas to be efficiently recycled into the process stream.

  8. Numerical, Laboratory And Field Studies of Gas Production From Natural Hydrate Accumulations in Geologic Media

    E-Print Network [OSTI]

    Moridis, George J.; Kneafsey, Timothy J.; Kowalsky, Michael; Reagan, Matthew

    2006-01-01T23:59:59.000Z

    hydrate (Class 1W) or gas and hydrate (Class 1G). In Class 1Economic Geology of Natural Gas Hydrates, M. Max, A.H. John-of the thermal test of gas hydrate dissociation in the

  9. Depressurization-induced gas production from Class 1 and Class 2 hydrate deposits

    E-Print Network [OSTI]

    Moridis, George J.; Kowalsky, Michael

    2006-01-01T23:59:59.000Z

    hydrate (Class 1W) or gas and hydrate (Class 1G). In Class 1Class 1G (involving gas and hydrate in the HBL). In Class 2JNOC/GSC Mallik 2L-38 Gas Hydrate Research Well, Mackenzie

  10. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    SciTech Connect (OSTI)

    Richard Sigal; Kent Newsham; Thomas Williams; Barry Freifeld; Timothy Kneafsey; Carl Sondergeld; Shandra Rai; Jonathan Kwan; Stephen Kirby; Robert Kleinberg; Doug Griffin

    2005-02-01T23:59:59.000Z

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu Formation and approximately 215 ft of porous sandstone were recovered in the West Sak Formation. There were gas shows in the bottom part of the Ugnu and throughout the West Sak. No hydrate-bearing zones were identified either in recovered core or on well logs. The base of the permafrost was found at about 1260 ft. With the exception of the deepest sands in the West Sak and some anomalous thin, tight zones, all sands recovered (after thawing) are unconsolidated with high porosity and high permeability. At 800 psi, Ugnu sands have an average porosity of 39.3% and geometrical mean permeability of 3.7 Darcys. Average grain density is 2.64 g/cc. West Sak sands have an average porosity of 35.5%, geometrical mean permeability of 0.3 Darcys, and average grain density of 2.70 g/cc. There were several 1-2 ft intervals of carbonate-cemented sandstone recovered from the West Sak. These intervals have porosities of only a few percent and very low permeability. On a well log they appear as resistive with a high sonic velocity. In shallow sections of other wells these usually are the only logs available. Given the presence of gas in Hot Ice No. 1, if only resistivity and sonic logs and a mud log had been available, tight sand zones may have been interpreted as containing hydrates. Although this finding does not imply that all previously mapped hydrate zones are merely tight sands, it does add a note of caution to the practice of interpreting the presence of hydrates from old well information. The methane hydrate stability zone below the Hot Ice No. 1 location includes thick sections of sandstone and conglomerate which would make excellent reservoir rocks for hydrates and below the permafrost zone shallow gas. The Ugnu formation comprises a more sand-rich section than does the West Sak formation, and the Ugnu sands when cleaned and dried are slightly more porous and significantly more permeable than the West Sak.

  11. Characterization of NOx Species in Dehydrated and Hydrated Na...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NOx Species in Dehydrated and Hydrated Na- and Ba-Y, FAU Zeolites Formed in NO Adsorption. Characterization of NOx Species in Dehydrated and Hydrated Na- and Ba-Y, FAU Zeolites...

  12. Method for production of hydrocarbons from hydrates

    DOE Patents [OSTI]

    McGuire, Patrick L. (Los Alamos, NM)

    1984-01-01T23:59:59.000Z

    A method of recovering natural gas entrapped in frozen subsurface gas hydrate formations in arctic regions. A hot supersaturated solution of CaCl.sub.2 or CaBr.sub.2, or a mixture thereof, is pumped under pressure down a wellbore and into a subsurface hydrate formation so as to hydrostatically fracture the formation. The CaCl.sub.2 /CaBr.sub.2 solution dissolves the solid hydrates and thereby releases the gas entrapped therein. Additionally, the solution contains a polymeric viscosifier, which operates to maintain in suspension finely divided crystalline CaCl.sub.2 /CaBr.sub.2 that precipitates from the supersaturated solution as it is cooled during injection into the formation.

  13. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

    Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)

    2003-01-01T23:59:59.000Z

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  14. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

    Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)

    1999-01-01T23:59:59.000Z

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  15. Curvature Dependence of Hydrophobic Hydration Dynamics

    E-Print Network [OSTI]

    R. Gregor Weiß; Matthias Heyden; Joachim Dzubiella

    2015-04-08T23:59:59.000Z

    We investigate the curvature-dependence of water dynamics in the vicinity of hydrophobic spherical solutes using molecular dynamics simulations. For both, the lateral and perpendicular diffusivity as well as for H-bond kinetics of water in the first hydration shell, we find a non-monotonic solute-size dependence, exhibiting extrema close to the well-known structural crossover length scale for hydrophobic hydration. Additionally, we find an apparently anomalous diffusion for water moving parallel to the surface of small solutes, which, however, can be explained by topology effects. The intimate connection between solute curvature, water structure and dynamics has implications for our understanding of hydration dynamics at heterogeneous biomolecular surfaces.

  16. Confined water in the low hydration regime

    E-Print Network [OSTI]

    P. Gallo; M. Rapinesi; M. Rovere

    2002-04-05T23:59:59.000Z

    Molecular dynamics results on water confined in a silica pore in the low hydration regime are presented. Strong layering effects are found due to the hydrophilic character of the substrate. The local properties of water are studied as function of both temperature and hydration level. The interaction of the thin films of water with the silica atoms induces a strong distortion of the hydrogen bond network. The residence time of the water molecules is dependent on the distance from the surface. Its behavior shows a transition from a brownian to a non-brownian regime approaching the substrate in agreement with results found in studies of water at contact with globular proteins.

  17. Dehydration of plutonium or neptunium trichloride hydrate

    DOE Patents [OSTI]

    Foropoulos, J. Jr.; Avens, L.R.; Trujillo, E.A.

    1992-03-24T23:59:59.000Z

    A process is described for preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride.

  18. Dehydration of plutonium or neptunium trichloride hydrate

    DOE Patents [OSTI]

    Foropoulos, Jr., Jerry (Los Alamos, NM); Avens, Larry R. (Los Alamos, NM); Trujillo, Eddie A. (Espanola, NM)

    1992-01-01T23:59:59.000Z

    A process of preparing anhydrous actinide metal trichlorides of plutonium or neptunium by reacting an aqueous solution of an actinide metal trichloride selected from the group consisting of plutonium trichloride or neptunium trichloride with a reducing agent capable of converting the actinide metal from an oxidation state of +4 to +3 in a resultant solution, evaporating essentially all the solvent from the resultant solution to yield an actinide trichloride hydrate material, dehydrating the actinide trichloride hydrate material by heating the material in admixture with excess thionyl chloride, and recovering anhydrous actinide trichloride is provided.

  19. Gas hydrates in the Gulf of Mexico

    E-Print Network [OSTI]

    Cox, Henry Benjamin

    1986-01-01T23:59:59.000Z

    GAS HYDRATES IN THE GULF OF MEXICO A Thesis by HENRY BENJAMIN COX Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1986 Major Subject...: Oceanography GAS HYDRATES IN THE GULF OF MEXICO A Thesis by HENRY BENJAMIN COX Approved as to style and content by: James M. Brooks (Chair of Committee) Leis M. Jef e (Member) Andre M. Landry, J (Member) Roger R. Fay (Member) Robert 0. Reid (Head...

  20. Dynamic behavior of hydration water in calcium-silicate-hydrate gel: A quasielastic neutron scattering spectroscopy investigation

    E-Print Network [OSTI]

    Li, Hua

    The translational dynamics of hydration water confined in calcium-silicate-hydrate (C-S-H) gel was studied by quasielastic neutron scattering spectroscopy in the temperature range from 280 to 230 K. The stretch exponent ...

  1. MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE

    E-Print Network [OSTI]

    Meyer, Christian

    MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE Feng Lin Submitted in partial and Sciences COLUMBIA UNIVERSITY 2006 #12;MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE;ABSTRACT MODELING OF HYDRATION KINETICS AND SHRINKAGE OF PORTLAND CEMENT PASTE Feng Lin A mathematical

  2. Videos of Experiments from ORNL Gas Hydrate Research

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Gas hydrate research performed by the Environmental Sciences Division utilizes the ORNL Seafloor Process Simulator, the Parr Vessel, the Sapphire Cell, a fiber optic distributed sensing system, and Raman spectroscopy. The group studies carbon sequestration in the ocean, desalination, gas hydrates in the solar system, and nucleation and dissociation kinetics. The videos available at the gas hydrates website are very short clips from experiments.

  3. Rock-physics Models for Gas-hydrate Systems Associated

    E-Print Network [OSTI]

    Texas at Austin, University of

    Rock-physics Models for Gas-hydrate Systems Associated with Unconsolidated Marine Sediments Diana at Austin, Austin, Texas, U.S.A. ABSTRACT R ock-physics models are presented describing gas-hydrate systems associated with unconsolidated marine sediments. The goals are to predict gas-hydrate concentration from

  4. The goal of this work is to quantify the Van der Waals interactions in systems involving gas hydrates. Gas hydrates are crystalline com-

    E-Print Network [OSTI]

    Boyer, Edmond

    gas hydrates. Gas hydrates are crystalline com- pounds that are often encountered in oil and gas briefly present the hydrate crystalline structure and the role of hydrates in oil-and gas industry the industrial contexts where they appear, we shall cite : hydrate plugs obstructing oil- or gas

  5. Multipole Electrostatics in Hydration Free Energy Calculations

    E-Print Network [OSTI]

    Ponder, Jay

    Multipole Electrostatics in Hydration Free Energy Calculations YUE SHI,1 CHUANJIE WU,2 JAY W Acceptance Ratio method. We have compared two approaches to derive the atomic multipoles from quantum mechanical calculations: one directly from the new distributed multipole analysis and the other involving

  6. Dynamics of Kr in dense clathrate hydrates.

    SciTech Connect (OSTI)

    Klug, D. D.; Tse, J. S.; Zhao, J. Y.; Sturhahn, W.; Alp, E. E.; Tulk, C. A. (X-Ray Science Division); (National Research Council of Canada); (Univ. of Saskatchewan); (ORNL)

    2011-01-01T23:59:59.000Z

    The dynamics of Kr atoms as guests in dense clathrate hydrate structures are investigated using site specific {sup 83}Kr nuclear resonant inelastic x-ray scattering (NRIXS) spectroscopy in combination with molecular dynamics simulations. The dense structure H hydrate and filled-ice structures are studied at high pressures in a diamond anvil high-pressure cell. The dynamics of Kr in the structure H clathrate hydrate quench recovered at 77 K is also investigated. The Kr phonon density of states obtained from the experimental NRIXS data are compared with molecular dynamics simulations. The temperature and pressure dependence of the phonon spectra provide details of the Kr dynamics in the clathrate hydrate cages. Comparison with the dynamics of Kr atoms in the low-pressure structure II obtained previously was made. The Lamb-Mossbauer factor obtained from NRIXS experiments and molecular dynamics calculations are in excellent agreement and are shown to yield unique information on the strength and temperature dependence of guest-host interactions.

  7. RESOURCE CHARACTERIZATION AND QUANTIFICATION OF NATURAL GAS-HYDRATE AND ASSOCIATED FREE-GAS ACCUMULATIONS IN THE PRUDHOE BAY - KUPARUK RIVER AREA ON THE NORTH SLOPE OF ALASKA

    SciTech Connect (OSTI)

    Robert Hunter; Shirish Patil; Robert Casavant; Tim Collett

    2003-06-02T23:59:59.000Z

    Interim results are presented from the project designed to characterize, quantify, and determine the commercial feasibility of Alaska North Slope (ANS) gas-hydrate and associated free-gas resources in the Prudhoe Bay Unit (PBU), Kuparuk River Unit (KRU), and Milne Point Unit (MPU) areas. This collaborative research will provide practical input to reservoir and economic models, determine the technical feasibility of gas hydrate production, and influence future exploration and field extension of this potential ANS resource. The large magnitude of unconventional in-place gas (40-100 TCF) and conventional ANS gas commercialization evaluation creates industry-DOE alignment to assess this potential resource. This region uniquely combines known gas hydrate presence and existing production infrastructure. Many technical, economical, environmental, and safety issues require resolution before enabling gas hydrate commercial production. Gas hydrate energy resource potential has been studied for nearly three decades. However, this knowledge has not been applied to practical ANS gas hydrate resource development. ANS gas hydrate and associated free gas reservoirs are being studied to determine reservoir extent, stratigraphy, structure, continuity, quality, variability, and geophysical and petrophysical property distribution. Phase 1 will characterize reservoirs, lead to recoverable reserve and commercial potential estimates, and define procedures for gas hydrate drilling, data acquisition, completion, and production. Phases 2 and 3 will integrate well, core, log, and long-term production test data from additional wells, if justified by results from prior phases. The project could lead to future ANS gas hydrate pilot development. This project will help solve technical and economic issues to enable government and industry to make informed decisions regarding future commercialization of unconventional gas-hydrate resources.

  8. Comparative Assessment of Advanced Gay Hydrate Production Methods

    SciTech Connect (OSTI)

    M. D. White; B. P. McGrail; S. K. Wurstner

    2009-06-30T23:59:59.000Z

    Displacing natural gas and petroleum with carbon dioxide is a proven technology for producing conventional geologic hydrocarbon reservoirs, and producing additional yields from abandoned or partially produced petroleum reservoirs. Extending this concept to natural gas hydrate production offers the potential to enhance gas hydrate recovery with concomitant permanent geologic sequestration. Numerical simulation was used to assess a suite of carbon dioxide injection techniques for producing gas hydrates from a variety of geologic deposit types. Secondary hydrate formation was found to inhibit contact of the injected CO{sub 2} regardless of injectate phase state, thus diminishing the exchange rate due to pore clogging and hydrate zone bypass of the injected fluids. Additional work is needed to develop methods of artificially introducing high-permeability pathways in gas hydrate zones if injection of CO{sub 2} in either gas, liquid, or micro-emulsion form is to be more effective in enhancing gas hydrate production rates.

  9. Rapid Gas Hydrate Formation Processes: Will They Work?

    SciTech Connect (OSTI)

    Brown, T.D.; Taylor, C.E.; Bernardo, M.P.

    2010-01-01T23:59:59.000Z

    Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETL’s 15-Liter Hydrate Cell. Results from this work demonstrate that the rapid and continuous formation of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve (see Figure 1).

  10. Rapid Gas Hydrate Formation Processes: Will They Work?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.

    2010-06-01T23:59:59.000Z

    Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETL’s 15-Liter Hydrate Cell. Results from this work demonstrate that the rapid and continuous formationmore »of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.« less

  11. TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of System Behavior in Hydrate-Bearing Geologic Media

    E-Print Network [OSTI]

    Moridis, George

    2008-01-01T23:59:59.000Z

    coexistence of aqueous, gas and hydrate phases in a cell (a deposit in which water, gas and hydrate are initially atequilibrium. The initial gas and hydrate saturations are S G

  12. X-ray CT Observations of Methane Hydrate Distribution Changes over Time in a Natural Sediment Core from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    and Englezos, P. , 2009. Gas hydrate formation in a variable1999. Formation of natural gas hydrates in marine sediments.1. Conceptual model of gas hydrate growth conditioned by

  13. Coupled multiphase fluid flow and wellbore stability analysis associated with gas production from oceanic hydrate-bearing sediments

    E-Print Network [OSTI]

    Rutqvist, J.

    2014-01-01T23:59:59.000Z

    Toward Production from Gas Hydrates: Current Status,Facing Gas Production From Gas-Hydrate Deposits. Society ofConference on Gas Hydrates (ICGH 2011), Edinburgh, Scotland,

  14. Evaluation of the Gas Production Potential of Marine Hydrate Deposits in the Ulleung Basin of the Korean East Sea

    E-Print Network [OSTI]

    Moridis, George J.; Reagan, Matthew T.; Kim, Se-Joon; Seol, Yongkoo; Zhang, Keni

    2007-01-01T23:59:59.000Z

    indicators for natural gas hydrates in shallow sediments ofInternational Symposium on Gas Hydrate Technology, Seoul,International Symposium on Gas Hydrate Technology, Seoul,

  15. Numerical studies of gas production from several CH4-hydrate zones at the Mallik Site, Mackenzie Delta, Canada

    E-Print Network [OSTI]

    Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Steven; Weatherill, Brian

    2002-01-01T23:59:59.000Z

    JNOC/GSC Mallik 2L-38 Gas Hydrate Research Well, Mackenziepermafrost- associated gas hydrate accumulation in theTerritories, Canada. A gas hydrate research well was drilled

  16. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    E-Print Network [OSTI]

    Seol, Yongkoo

    2010-01-01T23:59:59.000Z

    Formation of natural gas hydrates in marine sediments 1.Conceptual model of gas hydrate growth conditioned by hostPotential effects of gas hydrate on human welfare, Proc.

  17. Comparison of Kinetic and Equilibrium Reaction Models in Simulating the Behavior of Gas Hydrates in Porous Media

    E-Print Network [OSTI]

    Kowalsky, Michael B.; Moridis, George J.

    2006-01-01T23:59:59.000Z

    rate constant of methane gas hydrate decomposition, CanadianAdvances in the Study of Gas Hydrates, C. Taylor , J. Qwan,International Conference on Gas Hydrates, Trondheim, Norway,

  18. Gas Production From a Cold, Stratigraphically Bounded Hydrate Deposit at the Mount Elbert Site, North Slope, Alaska

    E-Print Network [OSTI]

    Moridis, G.J.

    2010-01-01T23:59:59.000Z

    of P, T, and gas and hydrate phase saturations (S G and SInternational Conference on Gas Hydrates, Vancouver, Britishinterrelations relative to gas hydrates within the North

  19. THERMODYNAMIC MODELLING OF GAS SEMI-CLATHRATE HYDRATES USING THE ELECTROLYTE NRTL MODEL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    THERMODYNAMIC MODELLING OF GAS SEMI-CLATHRATE HYDRATES USING THE ELECTROLYTE NRTL MODEL Matthias. For the description of the gas semiclathrate hydrate phase a combination of the salt hydrate model of Paricaud the applicability of the approach presented. Keywords: modeling, semiclathrate hydrate, gas semiclathrate hydrate, e

  20. International Conference on Gas Hydrates May 19-23, 2002, Yokohama

    E-Print Network [OSTI]

    Gudmundsson, Jon Steinar

    4th International Conference on Gas Hydrates May 19-23, 2002, Yokohama Cold Flow Hydrate Technology an opportunity for flow assurance in deepwater production of oil and gas. Hydrate R&D in the Natural Gas Hydrate exchange and reactor units. Introduction Hydrates form when liquid water and natural gas are in contact

  1. Multicavity SCRF calculation of ion hydration energies

    SciTech Connect (OSTI)

    Diercksen, B.H.F. [Max-Planck-Institut Fuer Astrophysik, Muenchen (Germany); Karelson, M. [Univ. of Tartu (Estonia); Tamm, T. [Univ. of Florida, Gainesville, FL (United States)

    1994-12-31T23:59:59.000Z

    The hydration energies of the proton, hydroxyl ion, and several inorganic ions were calculated using the multicavity self-consistent reaction field (MCa SCRF) method developed for the quantum-mechanical modeling of rotationally or flexible systems in dielectric media. The ionic complexes H{sub 3}O{sup +}(H2O){sub 4}, OH{sup {minus}}(H2O){sub 4}, NH{sup +}{sub 4}(H2O){sub 4}, and Hal{sup {minus}}(H2O){sub 4}, where Hal = F, Cl, or Br, have been studied. Each complex was divided between five spheres, corresponding to the central ion and four water molecules in their first coordination sphere, respectively. Each cavity was surrounded by a polarizable medium with the dielectric permittivity of water at room temperature (80). The ionic hydration energies of ions were divided into specific and nonspecific parts. After accounting for the cavity-formation energy using scaled particle theory, good agreement between the total calculated and experimental hydration energies was obtained for all ions studied.

  2. Development of Alaskan gas hydrate resources. Final report

    SciTech Connect (OSTI)

    Kamath, V.A.; Sharma, G.D.; Patil, S.L.

    1991-06-01T23:59:59.000Z

    The research undertaken in this project pertains to study of various techniques for production of natural gas from Alaskan gas hydrates such as, depressurization, injection of hot water, steam, brine, methanol and ethylene glycol solutions through experimental investigation of decomposition characteristics of hydrate cores. An experimental study has been conducted to measure the effective gas permeability changes as hydrates form in the sandpack and the results have been used to determine the reduction in the effective gas permeability of the sandpack as a function of hydrate saturation. A user friendly, interactive, menu-driven, numerical difference simulator has been developed to model the dissociation of natural gas hydrates in porous media with variable thermal properties. A numerical, finite element simulator has been developed to model the dissociation of hydrates during hot water injection process.

  3. CFD Modeling of Methane Production from Hydrate-Bearing Reservoir

    SciTech Connect (OSTI)

    Gamwo, I.K.; Myshakin, E.M.; Warzinski, R.P.

    2007-04-01T23:59:59.000Z

    Methane hydrate is being examined as a next-generation energy resource to replace oil and natural gas. The U.S. Geological Survey estimates that methane hydrate may contain more organic carbon the the world's coal, oil, and natural gas combined. To assist in developing this unfamiliar resource, the National Energy Technology Laboratory has undertaken intensive research in understanding the fate of methane hydrate in geological reservoirs. This presentation reports preliminary computational fluid dynamics predictions of methane production from a subsurface reservoir.

  4. Geomechanical Performance of Hydrate-Bearing Sediment in Offshore Environments

    SciTech Connect (OSTI)

    Stephen Holditch; Tad Patzek; Jonny Rutqvist; George Moridis; Richard Plumb

    2008-03-31T23:59:59.000Z

    The objective of this multi-year, multi-institutional research project was to develop the knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate-bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus was on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. We have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. We also investigated the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. The objective of the UC Berkeley work was to develop a grain-scale model of hydrate-bearing sediments. Hydrate dissociation alters the strength of HBS. In particular, transformation of hydrate clusters into gas and liquid water weakens the skeleton and, simultaneously, reduces the effective stress by increasing the pore pressure. The large-scale objective of the study is evaluation of geomechanical stability of offshore oil and gas production infrastructure. At Lawrence Berkeley National Laboratory (LBNL), we have developed the numerical model TOUGH + Hydrate + FLAC3D to evaluate how the formation and disassociation of hydrates in seafloor sediments affects seafloor stability. Several technical papers were published using results from this model. LBNL also developed laboratory equipment and methods to produce realistic laboratory samples of sediments containing gas hydrates so that mechanical properties could be measured in the laboratory. These properties are required to run TOUGH + Hydrate + FLAC3D to evaluate seafloor stability issues. At Texas A&M University we performed a detailed literature review to determine what gas hydrate formation properties had been measured and reported in the literature. We then used TOUGH + Hydrate to simulate the observed gas production and reservoir pressure field data at Messoyakha. We simulated various scenarios that help to explain the field behavior. We have evaluated the effect of reservoir parameters on gas recovery from hydrates. Our work should be beneficial to others who are investigating how to produce gas from a hydrate capped gas reservoir. The results also can be used to better evaluate the process of producing gas from offshore hydrates. The Schlumberger PETREL model is used in industry to the description of geologic horizons and the special distribution of properties. An interface between FLAC3D and Petrel was built by Schlumberger to allow for efficient data entry into TOUGH + Hydrate + FLAC3D.

  5. Examination of Hydrate Formation Methods: Trying to Create Representative Samples

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    Methods: Trying to Create Representative Samples Timothy J.Methods: Trying to Create Representative Samples Timothy J.Introduction Forming representative gas hydrate-bearing

  6. Method for the photocatalytic conversion of gas hydrates

    DOE Patents [OSTI]

    Taylor, Charles E. (Pittsburg, PA); Noceti, Richard P. (Pittsburg, PA); Bockrath, Bradley C. (Bethel Park, PA)

    2001-01-01T23:59:59.000Z

    A method for converting methane hydrates to methanol, as well as hydrogen, through exposure to light. The process includes conversion of methane hydrates by light where a radical initiator has been added, and may be modified to include the conversion of methane hydrates with light where a photocatalyst doped by a suitable metal and an electron transfer agent to produce methanol and hydrogen. The present invention operates at temperatures below 0.degree. C., and allows for the direct conversion of methane contained within the hydrate in situ.

  7. Energy Department Expands Research into Methane Hydrates, a Vast...

    Broader source: Energy.gov (indexed) [DOE]

    of methane in shallow subsurface and water columns, and the role gas hydrates play in carbon cycling. DOE Investment: approximately 650,000 Massachusetts Institute of...

  8. air clathrate hydrates: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the extent of hydration can be determined. In order to achieve this, development of a new pellet production method was essential. This technique facilitates the elimination of...

  9. airway surface hydration: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 200 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  10. angiogenesis vascularity hydration: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 177 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  11. alaskan gas hydrate: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 224 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  12. aluminum hydration effects: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I. Introduction Cementpaste,the binding phaseof concrete Bentz, Dale P. 258 NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration Engineering Websites Summary: NISTIR...

  13. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle D. (Golden, CO)

    1995-01-01T23:59:59.000Z

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member and/or six member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone.

  14. Increasing gas hydrate formation temperature for desalination of high salinity produced water with secondary guests

    SciTech Connect (OSTI)

    Cha, Jong-Ho [ORISE; Seol, Yongkoo [U.S. DOE

    2013-01-01T23:59:59.000Z

    We suggest a new gas hydrate-based desalination process using water-immiscible hydrate formers; cyclopentane (CP) and cyclohexane (CH) as secondary hydrate guests to alleviate temperature requirements for hydrate formation. The hydrate formation reactions were carried out in an isobaric condition of 3.1 MPa to find the upper temperature limit of CO2 hydrate formation. Simulated produced water (8.95 wt % salinity) mixed with the hydrate formers shows an increased upper temperature limit from ?2 °C for simple CO2 hydrate to 16 and 7 °C for double (CO2 + CP) and (CO2 + CH) hydrates, respectively. The resulting conversion rate to double hydrate turned out to be similar to that with simple CO2 hydrate at the upper temperature limit. Hydrate formation rates (Rf) for the double hydrates with CP and CH are shown to be 22 and 16 times higher, respectively, than that of the simple CO2 hydrate at the upper temperature limit. Such mild hydrate formation temperature and fast formation kinetics indicate increased energy efficiency of the double hydrate system for the desalination process. Dissociated water from the hydrates shows greater than 90% salt removal efficiency for the hydrates with the secondary guests, which is also improved from about 70% salt removal efficiency for the simple hydrates.

  15. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    E-Print Network [OSTI]

    Boswell, R.D.

    2010-01-01T23:59:59.000Z

    Advances in the Study of Gas Hydrates. Kluwer, New York, pp.and quantification of gas hydrates using rock physics andand Salt Inhibition of Gas Hydrate Formation in the Northern

  16. Estimation of composite thermal conductivity of a heterogeneous methane hydrate sample using iTOUGH2

    E-Print Network [OSTI]

    Gupta, Arvind; Kneafsey, Timothy J.; Moridis, George J.; Seol, Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

    2006-01-01T23:59:59.000Z

    International Conference on Gas Hydrates, Trondheim, Norway,Challenges for the future/gas hydrates, NYAS 912, 304, 2000.C. , Thermal state of the gas hydrate reservoir, natural gas

  17. Development of a Numerical Simulator for Analyzing the Geomechanical Performance of Hydrate-Bearing Sediments

    E-Print Network [OSTI]

    Rutqvist, J.

    2008-01-01T23:59:59.000Z

    J. Mienert. 2004. Effect of gas hydrates melting on seafloorInternational Conference on Gas Hydrates, Trondheim, Norway,A Documented Example of Gas Hydrate Saturated Sand in the

  18. The dynamic response of oceanic hydrate deposits to ocean temperature change

    E-Print Network [OSTI]

    Reagan, Matthew T.

    2008-01-01T23:59:59.000Z

    Moridis, G.J. (2007), Oceanic gas hydrate instability andand salt inhibition of gas hydrate formation in the northernI.R. (1999), Thermogenic gas hydrates and hydrocarbon gases

  19. Hydration-dependent dynamics of deeply cooled water under strong confinement

    E-Print Network [OSTI]

    Bertrand, C. E.

    We have measured the hydration-level dependence of the single-particle dynamics of water confined in the ordered mesoporous silica MCM-41. The dynamic crossover observed at full hydration is absent at monolayer hydration. ...

  20. Sensitivity Analysis of Gas Production from Class 2 and Class 3 Hydrate Deposits

    E-Print Network [OSTI]

    Reagan, Matthew

    2009-01-01T23:59:59.000Z

    a) temperature, (b) gas and hydrate phase saturations, and (A Documented Example of Gas Hydrate Saturated Sand in theMakogon, Y.F. , “Gas hydrates: frozen energy,” Recherche 18(

  1. Comparison of kinetic and equilibrium reaction models in simulating gas hydrate behavior in porous media

    E-Print Network [OSTI]

    Kowalsky, Michael B.; Moridis, George J.

    2006-01-01T23:59:59.000Z

    with Diapirism and Gas Hydrates at the Head of the Cape FearSea-Level Low Stands Above Gas Hydrate-Bearing Sediments.rate constant of methane gas hydrate decomposition. Canadian

  2. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

    E-Print Network [OSTI]

    Rutqvist, J.

    2009-01-01T23:59:59.000Z

    Conference on Gas Hydrates (ICGH 2008), Vancouver, BritishGSC et al. Mallik 5L-38 gas hydrate production research wellfrom the Mallik 2002 Gas Hydrate Production Research Well

  3. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    E-Print Network [OSTI]

    Boswell, R.D.

    2010-01-01T23:59:59.000Z

    and quantification of gas hydrates using rock physics andAdvances in the Study of Gas Hydrates. Kluwer, New York, pp.and Salt Inhibition of Gas Hydrate Formation in the Northern

  4. Modeling of Oceanic Gas Hydrate Instability and Methane Release in Response to Climate Change

    E-Print Network [OSTI]

    Reagan, Matthew T.

    2008-01-01T23:59:59.000Z

    Potential effects of gas hydrate on human welfare. Proc.W.S. A review of methane and gas hydrates in the dynamic,Geology of Natural Gas Hydrates, M. Max, A.H. Johnson, W.P.

  5. Basin scale assessment of gas hydrate dissociation in response to climate change

    E-Print Network [OSTI]

    Reagan, M.

    2012-01-01T23:59:59.000Z

    Moridis GJ. Oceanic gas hydrate instability and dissociationKA. Potential effects of gas hydrate on human welfare, Proc.WS. A review of methane and gas hydrates in the dynamic,

  6. Contribution of oceanic gas hydrate dissociation to the formation of Arctic Ocean methane plumes

    E-Print Network [OSTI]

    Reagan, M.

    2012-01-01T23:59:59.000Z

    V.A. Soloviev, Submarine Gas Hydrates. St. Petersburg, 1998.and stability of gas hydrate-related bottom-simulatingPotential effects of gas hydrate on human welfare, Proc.

  7. The Use of Horizontal Wells in Gas Production from Hydrate Accumulations

    E-Print Network [OSTI]

    Moridis, George J.

    2008-01-01T23:59:59.000Z

    E.D. Toward Production From Gas Hydrates: Current Status,International Conference on Gas Hydrates, Trondheim, Norway,for Gas Production from Gas Hydrate Reservoirs, J. Can. Pet.

  8. Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

    E-Print Network [OSTI]

    Rees, E.V.L.

    2012-01-01T23:59:59.000Z

    K. and McDonald, T. , Gas Hydrates of the Middle Americaet al. , Indian National Gas Hydrate Program Expedition 01et al. , Drilling Gas Hydrates on Hydrate Ridge, Cascadia

  9. Van't Hoff law for temperature dependent Langmuir constants in clathrate hydrate nanocavities

    E-Print Network [OSTI]

    Lakhlifi, Azzedine

    2015-01-01T23:59:59.000Z

    This work gives a van't Hoff law expression of Langmuir constants of different species for determining their occupancy in the nanocavities of clathrate hydrates. The van't Hoff law's parameters are derived from a fit with Langmuir constants calculated using a pairwise site-site interaction potential to model the anisotropic potential environment in the cavities, as a function of temperature. The parameters can be used for calculating clathrates compositions. Results are given for nineteen gas species trapped in the small and large cavities of structure types I and II [1]. The accuracy of this approach is based on a comparison with available experimental data for ethane and cyclo- propane clathrate hydrates. The numerical method applied in this work, was recently validated from a comparison with the spherical cell method based on analytical considerations [1

  10. Surfactant process for promoting gas hydrate formation and application of the same

    DOE Patents [OSTI]

    Rogers, Rudy E. (Starkville, MS); Zhong, Yu (Brandon, MS)

    2002-01-01T23:59:59.000Z

    This invention relates to a method of storing gas using gas hydrates comprising forming gas hydrates in the presence of a water-surfactant solution that comprises water and surfactant. The addition of minor amounts of surfactant increases the gas hydrate formation rate, increases packing density of the solid hydrate mass and simplifies the formation-storage-decomposition process of gas hydrates. The minor amounts of surfactant also enhance the potential of gas hydrates for industrial storage applications.

  11. Investigating the Metastability of Clathrate Hydrates for Energy Storage

    SciTech Connect (OSTI)

    Koh, Carolyn Ann [Colorado School of Mines

    2014-11-18T23:59:59.000Z

    Important breakthrough discoveries have been achieved from the DOE award on the key processes controlling the synthesis and structure-property relations of clathrate hydrates, which are critical to the development of clathrate hydrates as energy storage materials. Key achievements include: (i) the discovery of key clathrate hydrate building blocks (stable and metastable) leading to clathrate hydrate nucleation and growth; (ii) development of a rapid clathrate hydrate synthesis route via a seeding mechanism; (iii) synthesis-structure relations of H2 + CH4/CO2 binary hydrates to control thermodynamic requirements for energy storage and sequestration applications; (iv) discovery of a new metastable phase present during clathrate hydrate structural transitions. The success of our research to-date is demonstrated by the significant papers we have published in high impact journals, including Science, Angewandte Chemie, J. Am. Chem. Soc. Intellectual Merits of Project Accomplishments: The intellectual merits of the project accomplishments are significant and transformative, in which the fundamental coupled computational and experimental program has provided new and critical understanding on the key processes controlling the nucleation, growth, and thermodynamics of clathrate hydrates containing hydrogen, methane, carbon dioxide, and other guest molecules for energy storage. Key examples of the intellectual merits of the accomplishments include: the first discovery of the nucleation pathways and dominant stable and metastable structures leading to clathrate hydrate formation; the discovery and experimental confirmation of new metastable clathrate hydrate structures; the development of new synthesis methods for controlling clathrate hydrate formation and enclathration of molecular hydrogen. Broader Impacts of Project Accomplishments: The molecular investigations performed in this project on the synthesis (nucleation & growth)-structure-stability relations of clathrate hydrate systems are pivotal in the fundamental understanding of crystalline clathrate hydrates and the discovery of new clathrate hydrate properties and novel materials for a broad spectrum of energy applications, including: energy storage (hydrogen, natural gas); carbon dioxide sequestration; controlling hydrate formation in oil/gas transportation in subsea pipelines. The Project has also enabled the training of undergraduate, graduate and postdoctoral students in computational methods, molecular spectroscopy and diffraction, and measurement methods at extreme conditions of high pressure and low temperature.

  12. U.S. and Japan Complete Successful Field Trial of Methane Hydrate...

    Office of Environmental Management (EM)

    Japan Complete Successful Field Trial of Methane Hydrate Production Technologies U.S. and Japan Complete Successful Field Trial of Methane Hydrate Production Technologies May 2,...

  13. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    collection of additional reservoir data to support reservoirflow (drawdown) data for those hydrate reservoirs that aregeologic data on gas-hydrate-bearing sand reservoirs in the

  14. methane_hydrates | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengtheningWildfires mayYuan T.External Links ExternalMethane Hydrates Special

  15. Methane Hydrates R&D Program

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from aRodMIT-Harvard Center forMetallicH.Gas Hydrates

  16. CHARACTERIZATION OF MIXED CO2-TBPB HYDRATE FOR REFRIGERATION APPLICATIONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    CHARACTERIZATION OF MIXED CO2-TBPB HYDRATE FOR REFRIGERATION APPLICATIONS Pascal Clain , Anthony storage and distribution in refrigeration applications. Previous studies show that these hydrates are able.s] INTRODUCTION Secondary refrigeration is a method using a neutral fluid for cold distribution in order

  17. A pilot-scale continuous-jet hydrate reactor

    SciTech Connect (OSTI)

    Szymcek, Phillip [ORNL; McCallum, Scott [Oak Ridge Associated Universities (ORAU); Taboada Serrano, Patricia L [ORNL; Tsouris, Costas [ORNL

    2008-01-01T23:59:59.000Z

    A three-phase, pilot-scale continuous-jet hydrate reactor (CJHR) has been developed for the production of gas hydrates. The reactor receives water and a hydrate-forming species to produce the solid gas hydrate. The CJHR has been tested for the production of CO{sub 2} hydrate for the purpose of ocean carbon sequestration. Formation of CO{sub 2} hydrate was investigated using various reactor/injector designs in a 72-l high-pressure vessel. Designs of the CJHR varied from single-capillary to multiple-capillary injectors that dispersed (1) liquid CO{sub 2} into water or (2) water into liquid CO{sub 2}. The novel injector is designed to improve the dispersion of one reactant into the other and, thus, eliminate mass transfer barriers that negatively affect conversion. An additional goal was an increase in production rates of two orders of magnitude. The designed injectors were tested in both distilled and saline water. Hydrate production experiments were conducted at different CO{sub 2} and water flow rates and for pressures and temperatures equivalent to intermediate ocean depths (1100-1700 m). The pilot-scale reactor with the novel injection system successfully increased hydrate production rates and efficiency.

  18. Ice method for production of hydrogen clathrate hydrates

    DOE Patents [OSTI]

    Lokshin, Konstantin (Santa Fe, NM); Zhao, Yusheng (Los Alamos, NM)

    2008-05-13T23:59:59.000Z

    The present invention includes a method for hydrogen clathrate hydrate synthesis. First, ice and hydrogen gas are supplied to a containment volume at a first temperature and a first pressure. Next, the containment volume is pressurized with hydrogen gas to a second higher pressure, where hydrogen clathrate hydrates are formed in the process.

  19. Seismic-Scale Rock Physics of Methane Hydrate

    SciTech Connect (OSTI)

    Amos Nur

    2009-01-08T23:59:59.000Z

    We quantify natural methane hydrate reservoirs by generating synthetic seismic traces and comparing them to real seismic data: if the synthetic matches the observed data, then the reservoir properties and conditions used in synthetic modeling might be the same as the actual, in-situ reservoir conditions. This approach is model-based: it uses rock physics equations that link the porosity and mineralogy of the host sediment, pressure, and hydrate saturation, and the resulting elastic-wave velocity and density. One result of such seismic forward modeling is a catalogue of seismic reflections of methane hydrate which can serve as a field guide to hydrate identification from real seismic data. We verify this approach using field data from known hydrate deposits.

  20. Synthesis and characterization of a new structure of gas hydrate

    SciTech Connect (OSTI)

    Tulk, Christopher A [ORNL; Chakoumakos, Bryan C [ORNL; Ehm, Lars [Stony Brook University (SUNY); Klug, Dennis D [National Research Council of Canada; Parise, John B [Stony Brook University (SUNY); Yang, Ling [ORNL; Martin, Dave [Argonne National Laboratory (ANL); Ripmeester, John [National Research Council of Canada; Moudrakovski, Igor [National Research Council of Canada; Ratcliffe, Chris [National Research Council of Canada

    2009-01-01T23:59:59.000Z

    Atoms and molecules 0.4 0.9 nm in diameter can be incorporated in the cages formed by hydrogen-bonded water molecules making up the crystalline solid clathrate hydrates. There are three structural families of these hydrates , known as sI, sII and sH, and the structure usually depends on the largest guest molecule in the hydrate. Species such as Ar, Kr, Xe and methane form sI or sII hydrate, sH is unique in that it requires both small and large cage guests for stability. All three structures, containing methane, other hydrocarbons, H2S and CO2, O2 and N2 have been found in the geosphere, with sI methane hydrate by far the most abundant. At high pressures (P > 0.7 kbar) small guests (Ar, Kr, Xe, methane) are also known to form sH hydrate with multiple occupancy of the largest cage in the hydrate. The high-pressure methane hydrate of sH has been proposed as playing a role in the outer solar system, including formation models for Titan , and yet another high pressure phase of methane has been reported , although its structure remains unknown. In this study, we report a new and unique hydrate structure that is derived from the high pressure sH hydrate of xenon. After quench recovery at ambient pressure and 77 K it shows considerable stability at low temperatures (T < 160 K) and is compositionally similar to the sI Xe clathrate starting material. This evidence of structural complexity in compositionally similar clathrate compounds indicates that thermodynamic pressure temperature conditions may not be the only important factor in structure determination, but also the reaction path may have an important effect.

  1. CLATHRATE HYDRATES FORMATION IN SHORT-PERIOD COMETS

    SciTech Connect (OSTI)

    Marboeuf, Ulysse; Mousis, Olivier; Petit, Jean-Marc [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, 25010 Besancon Cedex (France); Schmitt, Bernard, E-mail: marboeuf@ujf-grenoble.f [Universite Joseph Fourier, Laboratoire de Planetologie de Grenoble, CNRS INSU (France)

    2010-01-01T23:59:59.000Z

    The initial composition of current models of cometary nuclei is only based on two forms of ice: crystalline ice for long-period comets and amorphous ice for short-period comets. A third form of ice, i.e., clathrate hydrate, could exist within the short-period cometary nuclei, but the area of formation of this crystalline structure in these objects has never been studied. Here, we show that the thermodynamic conditions in the interior of short-period comets allow the existence of clathrate hydrates in Halley-type comets. We show that their existence is viable in the Jupiter family comets only when the equilibrium pressure of CO clathrate hydrate is at least 1 order of magnitude lower than the usually assumed theoretical value. We calculate that the amount of volatiles that could be trapped in the clathrate hydrate layer may be orders of magnitude greater than the daily amount of gas released at the surface of the nucleus at perihelion. The formation and the destruction of the clathrate hydrate cages could then explain the diversity of composition of volatiles observed in comets, as well as some pre-perihelion outbursts. We finally show that the potential clathrate hydrate layer in comet 67P/Churyumov-Gerasimenko would, unfortunately, be deep inside the nucleus, out of reach of the Rosetta lander. However, such a clathrate hydrate layer would show up by the gas composition of the coma.

  2. Metal halogen battery system with multiple outlet nozzle for hydrate

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K. (Birmingham, MI)

    1983-06-21T23:59:59.000Z

    A metal halogen battery system, including at least one cell having a positive electrode and a negative electrode contacted by aqueous electrolyte containing the material of said metal and halogen, store means whereby halogen hydrate is formed and stored as part of an aqueous material, means for circulating electrolyte through the cell and to the store means, and conduit means for transmitting halogen gas formed in the cell to a hydrate former whereby the hydrate is formed in association with the store means, said store means being constructed in the form of a container which includes a filter means, said filter means being inoperative to separate the hydrate formed from the electrolyte, said system having, a hydrate former pump means associated with the store means and being operative to intermix halogen gas with aqueous electrolyte to form halogen hydrate, said hydrate former means including, multiple outlet nozzle means connected with the outlet side of said pump means and being operative to minimize plugging, said nozzle means being comprised of at least one divider means which is generally perpendicular to the rotational axes of gears within the pump means, said divider means acting to divide the flow from the pump means into multiple outlet flow paths.

  3. Cement & Concrete Science Conference: Leeds, 2009 Hydration of alite containing aluminium

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Cement & Concrete Science Conference: Leeds, 2009 Hydration of alite containing aluminium Begarin in cement is tricalcium silicate which leads during its hydration to the nucleation and growth of calcium silicate hydrate (referred to C-S-H (CaO)x-SiO2-(H2O)y). The development of this hydrate around the cement

  4. Micromechanics of Hydrate Dissociation in Marine Sediments by Grain-Scale Simulations

    E-Print Network [OSTI]

    Patzek, Tadeusz W.

    dissociation on the strength of hydrate-bearing sediments. Dissociation of gas-hydrates in marine sediments. Introduction Gas-hydrates are solid materials formed under a range of high pressures and low temperatures seek to evaluate the mechanical response to dissoci- ation of gas-hydrates in marine sediments

  5. E ects of the Driving Force on the Composition of Natural Gas Hydrates

    E-Print Network [OSTI]

    Gudmundsson, Jon Steinar

    E ects of the Driving Force on the Composition of Natural Gas Hydrates Odd I. Levik(1) , Jean for storage and transport of natural gas. Storage of natural gas in the form of hydrate at elevated pressure concept) (Gud- mundsson et al. 1998). Natural gas hydrate contains up to 182 Sm3 gas per m3 hydrate

  6. Driving force and composition for multicomponent gas hydrate nucleation from supersaturated aqueous solutions

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    formation in storage. Other interests include deep ocean carbon sequestration, use of hydrate deposits

  7. Comparison of kinetic and equilibrium reaction models in simulating gas hydrate behavior in porous media

    E-Print Network [OSTI]

    Kowalsky, Michael B.; Moridis, George J.

    2006-01-01T23:59:59.000Z

    hydrocarbons residing in hydrate deposits is estimated to substantially exceed all known conventional

  8. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

    E-Print Network [OSTI]

    Rutqvist, J.

    2009-01-01T23:59:59.000Z

    hydrocarbons) trapped in hydrates is enormous, and easily exceeds the equivalent of all the known conventional

  9. Geophysical constraints on the surface distribution of authigenic carbonates across the Hydrate Ridge region,

    E-Print Network [OSTI]

    Goldfinger, Chris

    the shallow source of methane and water contained in subsurface and surface gas hydrates. The distribution hemipelagic sediment. Hydrate Ridge lies within the gas hydrate stability field offshore central Oregon and during the last 15 years several studies have documented gas hydrate and cold seep carbonate occurrence

  10. Geophysical evidence for gas hydrates in the deep water of the South Caspian Basin, Azerbaijan

    E-Print Network [OSTI]

    Knapp, James Howard

    Geophysical evidence for gas hydrates in the deep water of the South Caspian Basin, Azerbaijan C) of this area, the presence of gas hydrates. Geophysical evidence for gas hydrates consists of a shallow (300, and is interpreted as the top of the gas hydrate layer. Similarly, a high-amplitude Rc

  11. Journal of Crystal Growth 243 (2002) 476489 Nucleation of gas hydrates

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    2002-01-01T23:59:59.000Z

    Journal of Crystal Growth 243 (2002) 476­489 Nucleation of gas hydrates Dimo Kashchieva , Abbas of nucleation of one-component gas hydrates in aqueous solutions are analyzed. The size of the hydrate nucleus. Nucleation; B1. Gas hydrates 1. Introduction Nucleation is perhaps the most challenging step in understanding

  12. Characterization of in situ elastic properties of gas hydrate-bearing sediments on the Blake Ridge

    E-Print Network [OSTI]

    Guerin, Gilles

    17 Chapter 2: Characterization of in situ elastic properties of gas hydrate-bearing sediments acquired in gas-hydrate bearing sediments on the Blake Ridge to characterize the very distinct seismic with free gas. Between these two depths, gas hydrate and free gas seem to coexist. Within the Gas Hydrate

  13. Evidence from threedimensional seismic tomography for a substantial accumulation of gas hydrate in a fluidescape

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Evidence from threedimensional seismic tomography for a substantial accumulation of gas hydrate to be associated with the emplacement of hydrate, accompanying the invasion of the gas hydrate stability zone accumulation of gas hydrate in a fluidescape chimney in the Nyegga pockmark field, offshore Norway, J. Geophys

  14. Gas hydrate research in the Gulf of Mexico: Final report

    SciTech Connect (OSTI)

    Bennet, R.

    1988-05-01T23:59:59.000Z

    The high energy seismic sections on the continental slope showed no evidence of a Bottom Simulating Reflector (BSR), which would indicate the presence of gas hydrates. There was no indication of metastable hydrates in continental shelf or slope sediments outside of the conventionally accepted temperature and pressure environment. Tracing the path of migrating gas from the source is much more straight forward than intercepting gas being transported and tracing it back to the source. Our study of low and medium energy seismic methods has shown that they could identify migrating gas. We feel strongly that there are hydrate zones in the Gulf of Mexico that are decomposing; they build up pressure and periodically release the trapped hydrocarbon gases. The released gases migrate vertically and/or laterally to mix with other types of gas or to form discrete pockets. Some of this gas may be emitted from underwater seeps into the overlying water column where it could be identified by a geochemical survey. The ratio of isobutane to normal butane determined by the geochemical survey can be used to assess the probability of the hydrocarbons emanating from a hydrate source. (The more the ratio exceeds 1.0 the greater the probability that the gas could be from a hydrate source.) As no indications of a hydrate zone (e.g., a BSR) were located, we were not able to establish a geophysical signature for gas hydrates; but the records indicate there are large volumes of gas migrating up the continental slope, some of which may have originated from a decomposing hydrate zone or from gas trapped below the hydrate cap. 20 refs., 13 figs., 1 tab.

  15. Simteche Hydrate CO2 Capture Process

    SciTech Connect (OSTI)

    Nexant and Los Alamos National Laboratory

    2006-09-30T23:59:59.000Z

    As a result of an August 4, 2005 project review meeting held at Los Alamos National Laboratory (LANL) to assess the project's technical progress, Nexant/Simteche/LANL project team was asked to meet four targets related to the existing project efforts. The four targets were to be accomplished by the September 30, 2006. These four targets were: (1) The CO{sub 2} hydrate process needs to show, through engineering and sensitivity analysis, that it can achieve 90% CO{sub 2} capture from the treated syngas stream, operating at 1000 psia. The cost should indicate the potential of achieving the Sequestration Program's cost target of less than 10% increase in the cost of electricity (COE) of the non-CO{sub 2} removal IGCC plant or demonstrate a significant cost reduction from the Selexol process cost developed in the Phase II engineering analysis. (2) The ability to meet the 20% cost share requirement for research level efforts. (3) LANL identifies through equilibrium and bench scale testing a once-through 90% CO{sub 2} capture promoter that supports the potential to achieve the Sequestration Program's cost target. Nexant is to perform an engineering analysis case to verify any economic benefits, as needed; no ETM validation is required, however, for this promoter for FY06. (4) The CO{sub 2} hydrate once-through process is to be validated at 1000 psia with the ETM at a CO{sub 2} capture rate of 60% without H{sub 2}S. The performance of 68% rate of capture is based on a batch, equilibrium data with H{sub 2}S. Validation of the test results is required through multiple runs and engineering calculations. Operational issues will be solved that will specifically effect the validation of the technology. Nexant was given the primary responsibility for Target No.1, while Simteche was mainly responsible for Target No.2; with LANL having the responsibility of Targets No.3 and No.4.

  16. Examination of Hydrate Formation Methods: Trying to Create Representative Samples

    SciTech Connect (OSTI)

    Kneafsey, T.J.; Rees, E.V.L.; Nakagawa, S.; Kwon, T.-H.

    2011-04-01T23:59:59.000Z

    Forming representative gas hydrate-bearing laboratory samples is important so that the properties of these materials may be measured, while controlling the composition and other variables. Natural samples are rare, and have often experienced pressure and temperature changes that may affect the property to be measured [Waite et al., 2008]. Forming methane hydrate samples in the laboratory has been done a number of ways, each having advantages and disadvantages. The ice-to-hydrate method [Stern et al., 1996], contacts melting ice with methane at the appropriate pressure to form hydrate. The hydrate can then be crushed and mixed with mineral grains under controlled conditions, and then compacted to create laboratory samples of methane hydrate in a mineral medium. The hydrate in these samples will be part of the load-bearing frame of the medium. In the excess gas method [Handa and Stupin, 1992], water is distributed throughout a mineral medium (e.g. packed moist sand, drained sand, moistened silica gel, other porous media) and the mixture is brought to hydrate-stable conditions (chilled and pressurized with gas), allowing hydrate to form. This method typically produces grain-cementing hydrate from pendular water in sand [Waite et al., 2004]. In the dissolved gas method [Tohidi et al., 2002], water with sufficient dissolved guest molecules is brought to hydrate-stable conditions where hydrate forms. In the laboratory, this is can be done by pre-dissolving the gas of interest in water and then introducing it to the sample under the appropriate conditions. With this method, it is easier to form hydrate from more soluble gases such as carbon dioxide. It is thought that this method more closely simulates the way most natural gas hydrate has formed. Laboratory implementation, however, is difficult, and sample formation is prohibitively time consuming [Minagawa et al., 2005; Spangenberg and Kulenkampff, 2005]. In another version of this technique, a specified quantity of gas is placed in a sample, then the sample is flooded with water and cooled [Priest et al., 2009]. We have performed a number of tests in which hydrate was formed and the uniformity of the hydrate formation was examined. These tests have primarily used a variety of modifications of the excess gas method to make the hydrate, although we have also used a version of the excess water technique. Early on, we found difficulties in creating uniform samples with a particular sand/ initial water saturation combination (F-110 Sand, {approx} 35% initial water saturation). In many of our tests we selected this combination intentionally to determine whether we could use a method to make the samples uniform. The following methods were examined: Excess gas, Freeze/thaw/form, Freeze/pressurize/thaw, Excess gas followed by water saturation, Excess water, Sand and kaolinite, Use of a nucleation enhancer (SnoMax), and Use of salt in the water. Below, each method, the underlying hypothesis, and our results are briefly presented, followed by a brief conclusion. Many of the hypotheses investigated are not our own, but were presented to us. Much of the data presented is from x-ray CT scanning our samples. The x-ray CT scanner provides a three-dimensional density map of our samples. From this map and the physics that is occurring in our samples, we are able to gain an understanding of the spatial nature of the processes that occur, and attribute them to the locations where they occur.

  17. Direct measurement of the correlated dynamics of the protein-backbone and proximal waters of hydration in mechanically strained elastin

    E-Print Network [OSTI]

    Cheng Sun; Odingo Mitchell; Jiaxin Huang; Gregory S. Boutis

    2011-04-05T23:59:59.000Z

    We report on the direct measurement of the correlation times of the protein backbone carbons and proximal waters of hydration in mechanically strained elastin by nuclear magnetic resonance methods. The experimental data indicate a decrease in the correlation times of the carbonyl carbons as the strain on the biopolymer is increased. These observations are in good agreement with short 4ns molecular dynamics simulations of (VPGVG)3, a well studied mimetic peptide of elastin. The experimental results also indicate a reduction in the correlation time of proximal waters of hydration with increasing strain applied to the elastomer. A simple model is suggested that correlates the increase in the motion of proximal waters of hydration to the increase in frequency of libration of the protein backbone that develops with increasing strain. Together, the reduction in the protein entropy accompanied with the increase in entropy of the proximal waters of hydration with increasing strain, support the notion that the source of elasticity is driven by an entropic mechanism arising from the change in entropy of the protein backbone.

  18. Methane hydrate gas production: evaluating and exploiting the solid gas resource

    SciTech Connect (OSTI)

    McGuire, P.L.

    1981-01-01T23:59:59.000Z

    Methane hydrate gas could be a tremendous energy resource if methods can be devised to produce this gas economically. This paper examines two methods of producing gas from hydrate deposits by the injection of hot water or steam, and also examines the feasibility of hydraulic fracturing and pressure reduction as a hydrate gas production technique. A hydraulic fracturing technique suitable for hydrate reservoirs and a system for coring hydrate reservoirs are also described.

  19. HEAT OF HYDRATION OF SALTSTONE MIXES-MEASUREMENT BY ISOTHERMAL CALORIMETRY

    SciTech Connect (OSTI)

    Harbour, J; Vickie Williams, V; Tommy Edwards, T

    2007-07-02T23:59:59.000Z

    This report provides initial results on the measurement of heat of hydration of Saltstone mixes using isothermal calorimetry. The results were obtained using a recently purchased TAM Air Model 3116 Isothermal Conduction Calorimeter. Heat of hydration is an important property of Saltstone mixes. Greater amounts of heat will increase the temperature of the curing mix in the vaults and limit the processing rate. The heat of hydration also reflects the extent of the hydraulic reactions that turn the fluid mixture into a ''stone like'' solid and consequently impacts performance properties such as permeability. Determining which factors control these reactions, as monitored by the heat of hydration, is an important goal of the variability study. Experiments with mixes of portland cement in water demonstrated that the heats measured by this technique over a seven day period match very well with the literature values of (1) seven day heats of hydration using the standard test method for heat of hydration of hydraulic cement, ASTM C 186-05 and (2) heats of hydration measured using isothermal calorimetry. The heats of hydration of portland cement or blast furnace slag in a Modular Caustic Side Solvent Extraction Unit (MCU) simulant revealed that if the cure temperature is maintained at 25 C, the amount of heat released over a seven day period is roughly 62% less than the heat released by portland cement in water. Furthermore, both the blast furnace slag and the portland cement were found to be equivalent in heat production over the seven day period in MCU. This equivalency is due to the activation of the slag by the greater than 1 Molar free hydroxide ion concentration in the simulant. Results using premix (a blend of 10% cement, 45% blast furnace slag, and 45% fly ash) in MCU, Deliquification, Dissolution and Adjustment (DDA) and Salt Waste Processing Facility (SWPF) simulants reveal that the fly ash had not significantly reacted (undergone hydration reactions) after seven days (most likely less than 5%). There were clear differences in the amount of heat released and the peak times of heat release for the three different simulants. It turns out that SWPF simulant mixes give off greater heat than does MCU and DDA simulant mixes. The temperature dependence of the heat of hydration was measured by carrying out these measurements at 25, 40 and 55 C. In general, the peak times shifted to shorter times as the isothermal temperature increased and the amount of heat released was independent of temperature for DDA and MCU but slightly higher at higher temperatures for SWPF. The goal of this study is to apply this technique to the measurement of the heat of hydration of mixes that will be made as part of the variability study. It is important to understand which variables will impact (and to what extent) the amount of heat generated and the peak times for the heat release. Those variables that can be controlled can then be tuned to adjust the heat of hydration as long as the other properties are still acceptable. The first application of heat of hydration measurements to the variability study was completed and the results presented in this report. These measurements were made using Phase VI mixes (SWPF simulants) following a statistical design that included variation in the compositional and operational variables. Variation in both the amount of heat released and the peak times for the heat release were observed. The measured ranges were 23 Joules per gram of premix for the heat release and 23 hours for the peak time of heat release at 25 C. Linear models with high R{sup 2} values and no statistical evidence for lack of fit were developed that relate the amount of heat release and the peak time for heat release for the Phase VI mixes to certain variables. The amount of heat released was a function of the aluminate and portland cement concentrations as well as the temperature of mixing. The peak time for heat release was a function of aluminate, portland cement and total nitrate plus nitrite concentrations. A comparison was made of the mea

  20. Effect of cryo-induced microcracks on microindentation of hydrated cortical bone tissue

    SciTech Connect (OSTI)

    Yin Ling, E-mail: ling.yin@jcu.edu.au [School of Engineering, James Cook University, Townsville, QLD 4811 (Australia); Venkatesan, Sudharshan [Department of Engineering, Australian National University, Canberra, ACT 0200 Australia (Australia); Webb, Daryl [Electron Microscopy Unit, Australian National University, Canberra, ACT 0200 (Australia); Kalyanasundaram, Shankar; Qin Qinghua [Department of Engineering, Australian National University, Canberra, ACT 0200 Australia (Australia)

    2009-08-15T23:59:59.000Z

    Microcracks accumulate in cortical bone tissue as a consequence of everyday cyclic loading. However, it remains unclear to what extent microdamage accumulation contributes to an increase in fracture risk. A cryo-preparation technique was applied to induce microcracks in cortical bone tissue. Microcracks with lengths up to approximately 20 {mu}m, which were initiated mainly on the boundaries of haversian canals, were observed with cryo-scanning electron microscopy. A microindentation technique was applied to study the mechanical loading effect on the microcracked hydrated bone tissue. The microindentation patterns were section-scanned using confocal laser scanning microscopy to understand the deformation and bone damage mechanisms made by mechanical loading. The results show that there was no significant difference with respect to microhardness between the original and microcracked hydrated cortical bone tissues (ANOVA, p > 0.05). The cryo-induced microcracks in the bone tissue were not propagated further under the mechanical loads applied. The deformation mechanism of the microcracked cortical bone tissue was plastic deformation, not brittle fracture.

  1. Simulation studies of slow dynamics of hydration water in lysozyme : hydration level dependence and comparison with experiment using new time domain analysis

    E-Print Network [OSTI]

    Kim, Chansoo, S.M. Massachusetts Institute of Technology

    2008-01-01T23:59:59.000Z

    A series of Molecular Dynamics (MD) simulations using the GROMACS® package has been performed in this thesis. It is used to mimic and simulate the hydration water in Lysozyme with three different hydration levels (h = 0.3, ...

  2. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, E.D. Jr.

    1995-07-11T23:59:59.000Z

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.

  3. Drilling Through Gas Hydrates Formations: Managing Wellbore Stability Risks

    E-Print Network [OSTI]

    Khabibullin, Tagir R.

    2010-10-12T23:59:59.000Z

    As hydrocarbon exploration and development moves into deeper water and onshore arctic environments, it becomes increasingly important to quantify the drilling hazards posed by gas hydrates. To address these concerns, a 1D semi-analytical model...

  4. Carbon dioxide hydrate particles for ocean carbon sequestration

    E-Print Network [OSTI]

    Chow, A.C.

    This paper presents strategies for producing negatively buoyant CO[subscript 2] hydrate composite particles for ocean carbon sequestration. Our study is based on recent field observations showing that a continuous-jet ...

  5. Strategies for gas production from oceanic Class 3 hydrate accumulations

    E-Print Network [OSTI]

    Moridis, George J.; Reagan, Matthew T.

    2007-01-01T23:59:59.000Z

    through the annular gravel pack (kg) N H = hydration numberthrough the annular gravel pack (kg/s) Q V = rate of CH 4ocean through the annular gravel pack (ST m 3 ) X i = water

  6. Effectiveness of Alcohol Cosurfactants in Hydrate Antiagglomeration Minwei Sun,

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    Firoozabadi*,, Reservoir Engineering Research Institute, 595 Lytton Ave. Suite B, Palo Alto, California 94301, especially in the deep sea, formation of gas hydrates may plug flowlines.1 There are significant safety

  7. Geotechnical characterization of sediments from Hydrate Ridge, Cascadia Continental Margin

    E-Print Network [OSTI]

    Tan, Brian B. (Brian Bautista), 1979-

    2004-01-01T23:59:59.000Z

    Eight whole core sediment samples were obtained from ODP Site 1244, Hydrate Ridge, Cascadia Continental Margin with the goal of understanding the stress history, consolidation behavior and strength characteristics of the ...

  8. Method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle D. (Golden, CO)

    1995-01-01T23:59:59.000Z

    Discussed is a process for preventing clathrate hydrate masses from impeding the flow of fluid in a fluid system. An additive is contacted with clathrate hydrate masses in the system to prevent those clathrate hydrate masses from impeding fluid flow. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include poly(N-vinyl-2-pyrrolidone) and hydroxyethylcellulose, either in combination or alone. Additives can also contain multiple cyclic chemical groupings having different size rings. One such additive is sold under the name Gaffix VC-713.

  9. An Integrated Study Method For Exploration Of Gas Hydrate Reservoirs...

    Open Energy Info (EERE)

    Method For Exploration Of Gas Hydrate Reservoirs In Marine Areas Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: An Integrated Study Method For...

  10. Drilling through gas hydrates formations: possible problems and suggested solution

    E-Print Network [OSTI]

    Amodu, Afolabi Ayoola

    2009-05-15T23:59:59.000Z

    .2.3 Case 310 This is the case of a gas hydrate buildup problem in a subsea christmas tree. The problem was that of a typical Campos Basin subsea well (1971.78ft water depth, 8oC at seabed) producing to a submarine production manifold on the seabed... ................................................................................. 14 2.3 Wellbore sketch for Case 2 ................................................................................. 17 2.4 Localization of gas hydrate in tree cap................................................................ 19 2.5a ROV...

  11. Natural gas hydrates - issues for gas production and geomechanical stability

    E-Print Network [OSTI]

    Grover, Tarun

    2008-10-10T23:59:59.000Z

    NATURAL GAS HYDRATES – ISSUES FOR GAS PRODUCTION AND GEOMECHANICAL STABILITY A Dissertation by TARUN GROVER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of DOCTOR OF PHILOSOPHY August 2008 Major Subject: Petroleum Engineering NATURAL GAS HYDRATES – ISSUES FOR GAS PRODUCTION AND GEOMECHANICAL STABILITY A Dissertation by TARUN GROVER Submitted to the Office of Graduate...

  12. The rate of isothermal hydration of polyperfluorosulfonic acid membranes

    E-Print Network [OSTI]

    Van Nguyen, Trung; Vanderborgh, N.

    1998-05-27T23:59:59.000Z

    The Rate of Isothermal Hydration of Polyperfluorosulfonic Acid Membranes by Trung Van Nguyen * Department of Chemical and Petroleum Engineering 4006 Learned Hall The University of Kansas Lawrence, Kansas 66045-2223 and Nicholas... conditions for the three phases of a typical polymer hydration dynamic experiment. Measurements were made using a TA3000 Mettler thermal analysis system. Nitrogen was used as the carrier gas along with controlled quantities of water vapor that were...

  13. Predicted geoacoustic properties of gas hydrate saturated marine sediments

    E-Print Network [OSTI]

    Curtis, William Robert

    1992-01-01T23:59:59.000Z

    PREDICTED GEOACOUSTIC PROPERTIES OF GAS HYDRATE SATURATED MAR&K SEDIMENTS A Thesis by WILLIAM ROBERT CURTIS JR. Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1992 Major Subject: Oceanography PREDICTED GEOACOUSTIC PROPERTIES OF GAS HYDRATE SATURATED MARINE SEDIMENTS A Thesis by WILLIAM ROBERT CURTIS JR. Approved as to style and content by; A brey L. Anderson (Chair of Committee...

  14. Evaluation of a deposit in the vicinity of the PBU L-106 Site, North Slope, Alaska, for a potential long-term test of gas production from hydrates

    E-Print Network [OSTI]

    Moridis, G.J.

    2010-01-01T23:59:59.000Z

    of P, T, and gas and hydrate phase saturations (S G and SInternational Conference on Gas Hydrates, Vancouver, BritishM. 2008. Investigation of gas hydrate bearing sandstone

  15. Examination of core samples from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Effects of retrieval and preservation

    E-Print Network [OSTI]

    Collett, T.J. Kneafsey, T.J., H. Liu, W. Winters, R. Boswell, R. Hunter, and T.S.

    2012-01-01T23:59:59.000Z

    and handling of natural gas hydrate. GSC Bulletin, 544: 263-naturally occurring gas hydrates: the structures of methanefrom the Mount Elbert Gas Hydrate Stratigraphic Test Well,

  16. Analysis of core samples from the BPXA-DOE-USGS Mount Elbert gas hydrate stratigraphic test well: Insights into core disturbance and handling

    E-Print Network [OSTI]

    Kneafsey, Timothy J.

    2010-01-01T23:59:59.000Z

    and handling of natural gas hydrate. GSC Bulletin, 544: 263-naturally occurring gas hydrates: the structures of methaneDOE-USGS Mount Elbert gas hydrate stratigraphic test well:

  17. Modeling pure methane hydrate dissociation using a numerical simulator from a novel combination of X-ray computed tomography and macroscopic data

    E-Print Network [OSTI]

    Gupta, A.

    2010-01-01T23:59:59.000Z

    From The Mallik 2002 Gas Hydrate Production Research Wellrate constant of methane gas hydrate decomposition. CanadianJNOC/GSC Mallik 2L-38 Gas Hydrate Research Well, Mackenzie

  18. Painting a Picture of Gas Hydrate Distribution with Thermal Images

    SciTech Connect (OSTI)

    Weinberger, Jill L.; Brown, Kevin M.; Long, Philip E.

    2005-02-25T23:59:59.000Z

    Large uncertainties about the energy resource potential and role in global climate change of gas hydrates result from uncertainty about how much hydrate is contained in marine sediments. During Leg 204 of the Ocean Drilling Program (ODP) to the accretionary complex of the Cascadia subduction zone, the entire gas hydrate stability zone was sampled in contrasting geological settings defined by a 3D seismic survey. By integrating results from different methods, including several new techniques developed for Leg 204, we overcome the problem of spatial under-sampling inherent in robust methods traditionally used for estimating the hydrate content of cores and obtain a high-resolution, quantitative estimate of the total amount and spatial variability of gas hydrate in this structural system. We conclude that high gas hydrate content (30-40% of pore space of 20-26% of total volume) is restricted to the upper tens of meters below the seafloor near the summit of the structure, where vigorous fluid venting occurs.

  19. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Frank R. Rack

    2006-09-20T23:59:59.000Z

    Cooperative Agreement DE-FC26-01NT41329 between Joint Oceanographic Institutions and DOE-NETL was divided into two phases based on successive proposals and negotiated statements of work pertaining to activities to sample and characterize methane hydrates on ODP Leg 204 (Phase 1) and on IODP Expedition 311 (Phase 2). The Phase 1 Final Report was submitted to DOE-NETL in April 2004. This report is the Phase 2 Final Report to DOE-NETL. The primary objectives of Phase 2 were to sample and characterize methane hydrates using the systems and capabilities of the D/V JOIDES Resolution during IODP Expedition 311, to enable scientists the opportunity to establish the mass and distribution of naturally occurring gas and gas hydrate at all relevant spatial and temporal scales, and to contribute to the DOE methane hydrate research and development effort. The goal of the work was to provide expanded measurement capabilities on the JOIDES Resolution for a dedicated hydrate cruise to the Cascadia continental margin off Vancouver Island, British Columbia, Canada (IODP Expedition 311) so that hydrate deposits in this region would be well characterized and technology development continued for hydrate research. IODP Expedition 311 shipboard activities on the JOIDES Resolution began on August 28 and were concluded on October 28, 2005. The statement of work for this project included three primary tasks: (1) research management oversight, provided by JOI; (2) mobilization, deployment and demobilization of pressure coring and core logging systems, through a subcontract with Geotek Ltd.; and, (3) mobilization, deployment and demobilization of a refrigerated container van that will be used for degassing of the Pressure Core Sampler and density logging of these pressure cores, through a subcontract with the Texas A&M Research Foundation (TAMRF). Additional small tasks that arose during the course of the research were included under these three primary tasks in consultation with the DOE-NETL Program Manager. All tasks outlined in the original statement of work were accomplished except for the deployment and use of the X-ray CT system under Subtask 2-2. This reduction in scope provided resources that were applied to other activities to support the overall project. Post-expedition analysis of results and report writing will continue beyond this reporting period, however, all field deployments associated with this project have been successfully concluded as of this writing.

  20. Ab initio investigation of the first hydration shell of protonated glycine

    SciTech Connect (OSTI)

    Wei, Zhichao; Chen, Dong, E-mail: dongchen@henu.edu.cn, E-mail: boliu@henu.edu.cn; Zhao, Huiling; Li, Yinli; Zhu, Jichun; Liu, Bo, E-mail: dongchen@henu.edu.cn, E-mail: boliu@henu.edu.cn [Institute of Photo-Biophysics, Physics and Electronics Department, Henan University, 475004 Kaifeng (China)] [Institute of Photo-Biophysics, Physics and Electronics Department, Henan University, 475004 Kaifeng (China)

    2014-02-28T23:59:59.000Z

    The first hydration shell of the protonated glycine is built up using Monte Carlo multiple minimum conformational search analysis with the MMFFs force field. The potential energy surfaces of the protonated glycine and its hydration complexes with up to eight water molecules have been scanned and the energy-minimized structures are predicted using the ab initio calculations. First, three favorable structures of protonated glycine were determined, and the micro-hydration processes showed that water can significantly stabilize the unstable conformers, and then their first hydration shells were established. Finally, we found that seven water molecules are required to fully hydrate the first hydration shell for the most stable conformer of protonated glycine. In order to analyse the hydration process, the dominant hydration sites located around the ammonium and carboxyl groups are studied carefully and systemically. The results indicate that, water molecules hydrate the protonated glycine in an alternative dynamic hydration process which is driven by the competition between different hydration sites. The first three water molecules are strongly attached by the ammonium group, while only the fourth water molecule is attached by the carboxyl group in the ultimate first hydration shell of the protonated glycine. In addition, the first hydration shell model has predicted most identical structures and a reasonable accord in hydration energy and vibrational frequencies of the most stable conformer with the conductor-like polarizable continuum model.

  1. Gas production from oceanic Class 2 hydrate accumulations

    SciTech Connect (OSTI)

    Moridis, G.J.; Reagan, M.T.

    2007-02-01T23:59:59.000Z

    Gas hydrates are solid crystalline compounds in which gasmolecules are lodged within the lattices of ice crystals. The vastamounts of hydrocarbon gases that are trapped in hydrate deposits in thepermafrost and in deep ocean sediments may constitute a promising energysource. Class 2 hydrate deposits are characterized by a Hydrate-BearingLayer (HBL) that is underlain by a saturated zone of mobile water. Inthis study we investigated three methods of gas production via verticalwell designs. A long perforated interval (covering the hydrate layer andextending into the underlying water zone) yields the highest gasproduction rates (up to 20 MMSCFD), but is not recommended for long-termproduction because of severe flow blockage caused by secondary hydrateand ice. A short perforated interval entirely within the water zoneallows long-term production, but only at rates of 4.5 7 MMSCFD. A newwell design involving localized heating appears to be the most promising,alleviating possible blockage by secondary hydrate and/or ice near thewellbore) and delivering sustainably large, long-term rates (10-15MMSCFD).The production strategy involves a cyclical process. During eachcycle, gas production continuously increases, while the correspondingwater production continuously decreases. Each cycle is concluded by acavitation event (marked by a precipitous pressure drop at the well),brought about by the inability of thesystem to satisfy the constant massproduction rate QM imposed at the well. This is caused by the increasinggas contribution to the production stream, and/or flow inhibition causedby secondary hydrate and/or ice. In the latter case, short-term thermalstimulation removes the blockage. The results show that gas productionincreases (and the corresponding water-to-gas ratio RWGC decreases) withan increasing(a) QM, (b) hydrate temperature (which defines its stabilityfor a given pressure), and (c) intrinsic permeability. Lower initialhydrate saturations lead initially to higher gas production and a lowerRWGC, but the effect is later reversed as the hydrate is depleted. Thedisposal of the large amounts of produced water does not appear to pose asignificant environmental problem. Production from Class 2 hydrates ischaracterized by (a) the need for confining boundaries, (b) thecontinuously improving RWGC over time (opposite to conventional gasreservoirs), and (c) the development of a free gas zone at the top of thehydrate layer (necessitating the existence of a gas cap forproduction).

  2. Pressure-induced Hydration in Zeolite Tetranatrolite

    SciTech Connect (OSTI)

    Lee,Y.; Hriljac, J.; Parise, J.; Vogt, T.

    2006-01-01T23:59:59.000Z

    The tetranatrolite-paranatrolite transformation has remained a key problem in understanding the paragenesis of zeolites in the natrolite family. It is accepted that when paranatrolite, approximate formula Na{sub 16-x}Ca{sub x}Al{sub 16+x}Si{sub 24-x}O{sub 80}{center_dot}24H{sub 2}O, is removed from an aqueous environment and exposed to the atmosphere, it loses water and transforms to tetranatrolite, Na{sub 16-x}Ca{sub x}Al{sub 16+x}Si{sub 24-x}O{sub 80}{center_dot}nH{sub 2}O (n {le} 24). Here we show that this transformation is not only reversible, but that tetranatrolite exhibits two sequential pressure-induced hydrations leading first to paranatrolite and then to a superhydrated tetranatrolite above 0.2 and 3.0 GPa, respectively. We have previously reported similar behavior for the corresponding system with an ordered Si/Al distribution, i.e., natrolite itself, however the ordered version of paranatrolite exists over a much smaller pressure range. The pressure-induced transformations of natrolite and tetranatrolite thus further supports the supposition that paranatrolite is a distinct mineral species, with a pressure-stability field dependent upon composition.

  3. X-ray CT Observations of Methane Hydrate Distribution Changes over Time in a Natural Sediment Core from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well

    E-Print Network [OSTI]

    Kneafsey, T.J.

    2012-01-01T23:59:59.000Z

    and Englezos, P. , 2009. Gas hydrate formation in a variableDOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test WellFormation of natural gas hydrates in marine sediments. 1.

  4. Dynamics of lysozyme and its hydration water under electric field

    E-Print Network [OSTI]

    P. M. Favi; Q. Zhang; H. O'Neill; E. Mamontov; S. O. Diallo

    2013-12-06T23:59:59.000Z

    The effects of static electric field on the dynamics of lysozyme and its hydration water have been investigated by means of incoherent quasi-elastic neutron scattering (QENS). Measurements were performed on lysozyme samples, hydrated respectively with heavy water (D2O) to capture the protein dynamics, and with light water (H2O), to probe the dynamics of the hydration shell, in the temperature range from 210 $hydration fraction in both cases was about $\\sim$ 0.38 gram of water per gram of dry protein. The field strengths investigated were respectively 0 kV/mm and 2 kV/mm (2 10$^6$ V/m) for the protein hydrated with D2O and 0 kV and 1 kV/mm for the H2O hydrated counterpart. While the overall internal protons dynamics of the protein appears to be unaffected by the application of electric field up to 2 kV/mm, likely due to the stronger intra-molecular interactions, there is also no appreciable quantitative enhancement of the diffusive dynamics of the hydration water, as would be anticipated based on our recent observations in water confined in silica pores under field values of 2.5 kV/mm. This may be due to the difference in surface interactions between water and the two adsorption hosts (silica and protein), or to the existence of a critical threshold field value Ec $\\sim$ 2-3 kV/mm for increased molecular diffusion, for which electrical breakdown is a limitation for our sample.

  5. Response of oceanic hydrate-bearing sediments to thermalstresses

    SciTech Connect (OSTI)

    Moridis, G.J.; Kowalsky, M.B.

    2006-05-01T23:59:59.000Z

    In this study, we evaluate the response of oceanicsubsurface systems to thermal stresses caused by the flow of warm fluidsthrough noninsulated well systems crossing hydrate-bearing sediments.Heat transport from warm fluids, originating from deeper reservoirs underproduction, into the geologic media can cause dissociation of the gashydrates. The objective of this study is to determine whether gasevolution from hydrate dissociation can lead to excessive pressurebuildup, and possibly to fracturing of hydrate-bearing formations andtheir confining layers, with potentially adverse consequences on thestability of the suboceanic subsurface. This study also aims to determinewhether the loss of the hydrate--known to have a strong cementing effecton the porous media--in the vicinity of the well, coupled with thesignificant pressure increases, can undermine the structural stability ofthe well assembly.Scoping 1D simulations indicated that the formationintrinsic permeability, the pore compressibility, the temperature of theproduced fluids andthe initial hydrate saturation are the most importantfactors affecting the system response, while the thermal conductivity andporosity (above a certain level) appear to have a secondary effect.Large-scale simulations of realistic systems were also conducted,involving complex well designs and multilayered geologic media withnonuniform distribution of properties and initial hydrate saturationsthat are typical of those expected in natural oceanic systems. Theresults of the 2D study indicate that although the dissociation radiusremains rather limited even after long-term production, low intrinsicpermeability and/or high hydrate saturation can lead to the evolution ofhigh pressures that can threaten the formation and its boundaries withfracturing. Although lower maximum pressures are observed in the absenceof bottom confining layers and in deeper (and thus warmer and morepressurized) systems, the reduction is limited. Wellbore designs withgravel packs that allow gas venting and pressure relief result insubstantially lower pressures.

  6. CX-010977: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Thermal-Hydrological-Chemical-Mechanical (THCM) Coupled Model for Hydrate-Bearing Sediments: Data Analysis and Design of New Field Experiments CX(s) Applied: A9 Date: 09/16/2013 Location(s): Georgia Offices(s): National Energy Technology Laboratory

  7. CX-010976: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Thermal-Hydrological-Chemical-Mechanical (THCM) Coupled Model for Hydrate-Bearing Sediments: Data Analysis and Design of New Field Experiments CX(s) Applied: A9 Date: 09/16/2013 Location(s): Texas Offices(s): National Energy Technology Laboratory

  8. CX-009278: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Measurement and Interpretation of Seismic Velocities and Attenuation in Hydrate-Bearing Sediments CX(s) Applied: A9, B2.2, B3.6 Date: 09/07/2012 Location(s): Colorado Offices(s): National Energy Technology Laboratory

  9. CX-010922: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Borehole Tool for the Comprehensive Characterization of Hydrate-Bearing Sediments CX(s) Applied: A1, A9, B3.6, Other: Bench Scale Laboratory Research Date: 09/25/2013 Location(s): Georgia Offices(s): National Energy Technology Laboratory

  10. Gas Production From a Cold, Stratigraphically Bounded Hydrate Deposit at the Mount Elbert Site, North Slope, Alaska

    E-Print Network [OSTI]

    Moridis, G.J.

    2010-01-01T23:59:59.000Z

    of P, T, and gas and hydrate phase saturations (S G and SJNOC/GSC Mallik 2L-38 Gas Hydrate Research-Well Sediments,interrelations relative to gas hydrates within the North

  11. Phase Equilibria Studies in Water-Methane System: Structural Memory-Effect of Water On Hydrate Re-Formation

    E-Print Network [OSTI]

    Kim, Brice Yoonshik

    2014-12-08T23:59:59.000Z

    Naturally-occurring hydrates are promising resources. The potential value of gas accumulation in naturally-occurring gas hydrates can exceed 16 equivalent trillion tons of oil. There are many accurate findings on properties of gas hydrates...

  12. Application of the Split Hopkinson Resonant Bar Test for Seismic Property Characterization of Hydrate-bearing Sand Undergoing Water Saturation

    E-Print Network [OSTI]

    Nakagawa, S.

    2012-01-01T23:59:59.000Z

    E.V.L. 2009. Methane Gas Hydrate Morphology and its EffectGEO-SEQ Program and Gas Hydrate Program, through theInternational Conference on Gas Hydrates , Yokohama, 856–

  13. Toward Production From Gas Hydrates: Current Status, Assessment of Resources, and Simulation-Based Evaluation of Technology and Potential

    E-Print Network [OSTI]

    Moridis, George J.

    2008-01-01T23:59:59.000Z

    the second involves gas and hydrate (Class 1G, water-poorpriorities for marine gas hydrates, Fire In The Ice, NETLCollett, T. , 1993, Natural gas hydrates of the Prudhoe Bay

  14. A Domain Decomposition Approach for Large-Scale Simulations of Flow Processes in Hydrate-Bearing Geologic Media

    E-Print Network [OSTI]

    Zhang, Keni

    2009-01-01T23:59:59.000Z

    In this deposit, water, gas, and hydrate are initially atwhen exhaustion of the free gas and hydrate resources in theAdvances in the Study of Gas Hydrates, C. Taylor and J.

  15. Numerical simulation studies of gas production scenarios from hydrate accumulations at the Mallik Site, McKenzie Delta, Canada

    E-Print Network [OSTI]

    Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Stephen; Weatherhill, Brian

    2002-01-01T23:59:59.000Z

    permafrost-associated gas hydrate accumulation in theCanada. An 1150 m deep gas hydrate research well was drilledscenarios from several gas-hydrate-bearing zones at the

  16. Coupled multiphase fluid flow and wellbore stability analysis associated with gas production from oceanic hydrate-bearing sediments

    E-Print Network [OSTI]

    Rutqvist, J.

    2014-01-01T23:59:59.000Z

    and arctic onshore gas hydrate production wells. OTC-21015.Bay Unit L-106 Well Unit C gas hydrate deposit in Alaska.Toward Production from Gas Hydrates: Current Status,

  17. Methane Hydrate Field Program: Development of a Scientific Plan for a Methane Hydrate-Focused Marine Drilling, Logging and Coring Program

    SciTech Connect (OSTI)

    Collett, Tim; Bahk, Jang-Jun; Frye, Matt; Goldberg, Dave; Husebo, Jarle; Koh, Carolyn; Malone, Mitch; Shipp, Craig; Torres, Marta; Myers, Greg; Divins, David; Morell, Margo

    2013-11-30T23:59:59.000Z

    This topical report represents a pathway toward better understanding of the impact of marine methane hydrates on safety and seafloor stability and future collection of data that can be used by scientists, engineers, managers and planners to study climate change and to assess the feasibility of marine methane hydrate as a potential future energy resource. Our understanding of the occurrence, distribution and characteristics of marine methane hydrates is incomplete; therefore, research must continue to expand if methane hydrates are to be used as a future energy source. Exploring basins with methane hydrates has been occurring for over 30 years, but these e?orts have been episodic in nature. To further our understanding, these e?orts must be more regular and employ new techniques to capture more data. This plan identifies incomplete areas of methane hydrate research and o?ers solutions by systematically reviewing known methane hydrate “Science Challenges” and linking them with “Technical Challenges” and potential field program locations.

  18. The use of electrical impedance spectroscopy for monitoring the hydration products of Portland cement mortars with high percentage of pozzolans

    SciTech Connect (OSTI)

    Cruz, J.M. [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain)] [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain); Fita, I.C., E-mail: infifer@fis.upv.es [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain); Soriano, L.; Payá, J.; Borrachero, M.V. [ICITECH, Instituto de Ciencia y Tecnología del Hormigón, Universitat Politècnica de València (Spain)] [ICITECH, Instituto de Ciencia y Tecnología del Hormigón, Universitat Politècnica de València (Spain)

    2013-08-15T23:59:59.000Z

    In this paper, mortars and pastes containing large replacement of pozzolan were studied by mechanical strength, thermogravimetric analysis (TGA), scanning electronic microscopy (SEM), mercury intrusion porosimetry (MIP) and electrical impedance spectroscopy (EIS). The effect of metakaolin (35%) and fly ash (60%) was evaluated and compared with an inert mineral addition (andalusite). The portlandite content was measured, finding that the pozzolanic reaction produced cementing systems with all portlandite fixed. The EIS measurements were analyzed by the equivalent electrical circuit (EEC) method. An EEC with three branches in parallel was applied. The dc resistance was related to the degree of hydration and allowed us to characterize plain and blended mortars. A constant phase element (CPE) quantified the electrical properties of the hydration products located in the solid–solution interface and was useful to distinguish the role of inert and pozzolanic admixtures present in the cement matrix.

  19. Hydration water dynamics and instigation of protein structuralrelaxation

    SciTech Connect (OSTI)

    Russo, Daniela; Hura, Greg; Head-Gordon, Teresa

    2003-09-01T23:59:59.000Z

    Until a critical hydration level is reached, proteins do not function. This critical level of hydration is analogous to a similar lack of protein function observed for temperatures below a dynamical temperature range of 180-220K that also is connected to the dynamics of protein surface water. Restoration of some enzymatic activity is observed in partially hydrated protein powders, sometimes corresponding to less than a single hydration layer on the protein surface, which indicates that the dynamical and structural properties of the surface water is intimately connected to protein stability and function. Many elegant studies using both experiment and simulation have contributed important information about protein hydration structure and timescales. The molecular mechanism of the solvent motion that is required to instigate the protein structural relaxation above a critical hydration level or transition temperature has yet to be determined. In this work we use experimental quasi-elastic neutron scattering (QENS) and molecular dynamics simulation to investigate hydration water dynamics near a greatly simplified protein system. We consider the hydration water dynamics near the completely deuterated N-acetyl-leucine-methylamide (NALMA) solute, a hydrophobic amino acid side chain attached to a polar blocked polypeptide backbone, as a function of concentration between 0.5M-2.0M under ambient conditions. We note that roughly 50-60% of a folded protein's surface is equally distributed between hydrophobic and hydrophilic domains, domains whose lengths are on the order of a few water diameters, that justify our study of hydration dynamics of this simple model protein system. The QENS experiment was performed at the NIST Center for Neutron Research, using the disk chopper time of flight spectrometer (DCS). In order to separate the translational and rotational components in the spectra, two sets of experiments were carried out using different incident neutron wavelengths of 7.5{angstrom} and 5.5{angstrom} to give two different time resolutions. All the spectra have been measure at room temperature. The spectra were corrected for the sample holder contribution and normalized using the vanadium standard. The resulting data were analyzed with DAVE programs (http://www.ncnr.nist.gov/dave/). The AMBER force field and SPCE water model were used for modeling the NALMA solute and water, respectively. For the analysis of the water dynamics in the NALMA aqueous solutions, we performed simulations of a dispersed solute configuration consistent with our previous structural analysis, where we had primarily focused on the structural organization of these peptide solutions and their connection to protein folding. Further details of the QENS experiment and molecular dynamics simulations are reported elsewhere.

  20. Carbon Dioxide Hydrate Particles for Ocean Carbon Sequestration

    SciTech Connect (OSTI)

    Chow, Aaron C. [Massachusetts Institute of Technology (MIT); Adams, E. Eric [Massachusetts Institute of Technology (MIT); Israelsson, P. H. [Quantitative Environmental Analysis; Tsouris, Costas [ORNL

    2009-01-01T23:59:59.000Z

    This paper presents strategies for producing negatively buoyant CO{sub 2} hydrate composite particles for ocean carbon sequestration. Our study is based on recent field observations showing that a continuous-jet hydrate reactor located at an ocean depth of 1500 m produced curved negatively buoyant cylindrical particles with diameters {approx} 2.5 cm and lengths up to {approx} 1 m. Accordingly we performed new laboratory experiments to determine the drag coefficient of such particles and, based on the measured drag coefficient and the initial settling velocity observed in the field, have concluded that the reactor efficiency (percentage of liquid CO{sub 2} converted to hydrate) in the field was {approx} 16%. Using the dissolution rates observed in the field, we conclude that such particles would ultimately sink to depth below discharge of {approx} 115 m. We have also predicted the sinking depth of particles potentially produced from various scaled-up reactors and have shown that, for example, a 10 cm diameter particle produced with a hydrate conversion of 50% could reach the ocean bottom before completely dissolving. In a real sequestration scenario, we are interested in following large groups of hydrate particles released continuously. We have previously shown that increasing particle size and hydrate conversion efficiency enhances the sinking of hydrate particle plumes produced by the continuous release of CO{sub 2} in a quiescent ambient, but that a sufficiently strong current will cause the entrained particles to separate from the plume and settle discretely. In the latter case, particles of different sizes and hydrate conversions (hence different settling velocities) will follow different settling trajectories as they dissolve. This particle fractionation, if employed deliberately, spreads the discharged CO{sub 2} in the down current and vertical directions, enhancing mixing, while turbulent diffusion helps spread the CO{sub 2} in the third direction. A numerical model that incorporates these processes is used to predict the downstream concentrations and changes in pH from such particle plumes in a 'strong' current. An extension of this model simulates hydrate particles that are released continuously from a moving ship. Because of the ship speed, such particles would never form a coherent plume, but the combination of particle fractionation and advection due to the ship motion produces excellent dilution of the discharged CO{sub 2}.

  1. Integrating Natural Gas Hydrates in the Global Carbon Cycle

    SciTech Connect (OSTI)

    David Archer; Bruce Buffett

    2011-12-31T23:59:59.000Z

    We produced a two-dimensional geological time- and basin-scale model of the sedimentary margin in passive and active settings, for the simulation of the deep sedimentary methane cycle including hydrate formation. Simulation of geochemical data required development of parameterizations for bubble transport in the sediment column, and for the impact of the heterogeneity in the sediment pore fluid flow field, which represent new directions in modeling methane hydrates. The model is somewhat less sensitive to changes in ocean temperature than our previous 1-D model, due to the different methane transport mechanisms in the two codes (pore fluid flow vs. bubble migration). The model is very sensitive to reasonable changes in organic carbon deposition through geologic time, and to details of how the bubbles migrate, in particular how efficiently they are trapped as they rise through undersaturated or oxidizing chemical conditions and the hydrate stability zone. The active margin configuration reproduces the elevated hydrate saturations observed in accretionary wedges such as the Cascadia Margin, but predicts a decrease in the methane inventory per meter of coastline relative to a comparable passive margin case, and a decrease in the hydrate inventory with an increase in the plate subduction rate.

  2. Structural stability of methane hydrate at high pressures

    SciTech Connect (OSTI)

    Shu, Jinfu; Chen, Xiaojia; Chou, I.-Ming; Yang, Wenge; Hu, Jingzhu; Hemley, Russell J.; Mao, Ho-kwang

    2011-01-01T23:59:59.000Z

    The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil cells. The diffraction data for types II (sII) and H (sH) were refined to the known structures with space groups Fd3m and P6{sub 3}/mmc, respectively. Upon compression, sI methane hydrate transforms to the sII phase at 120 MPa, and then to the sH phase at 600 MPa. The sII methane hydrate was found to coexist locally with sI phase up to 500 MPa and with sH phase up to 600 MPa. The pure sH structure was found to be stable between 600 and 900 MPa. Methane hydrate decomposes at pressures above 3 GPa to form methane with the orientationally disordered Fm3m structure and ice VII (Pn3m). The results highlight the role of guest (CH{sub 4})-host (H{sub 2}O) interactions in the stabilization of the hydrate structures under pressure.

  3. Variability of the methane trapping in martian subsurface clathrate hydrates

    E-Print Network [OSTI]

    Caroline Thomas; Olivier Mousis; Sylvain Picaud; Vincent Ballenegger

    2008-10-23T23:59:59.000Z

    Recent observations have evidenced traces of methane CH4 heterogeneously distributed in the martian atmosphere. However, because the lifetime of CH4 in the atmosphere of Mars is estimated to be around 300-600 years on the basis of photochemistry, its release from a subsurface reservoir or an active primary source of methane have been invoked in the recent literature. Among the existing scenarios, it has been proposed that clathrate hydrates located in the near subsurface of Mars could be at the origin of the small quantities of the detected CH4. Here, we accurately determine the composition of these clathrate hydrates, as a function of temperature and gas phase composition, by using a hybrid statistical thermodynamic model based on experimental data. Compared to other recent works, our model allows us to calculate the composition of clathrate hydrates formed from a more plausible composition of the martian atmosphere by considering its main compounds, i.e. carbon dioxyde, nitrogen and argon, together with methane. Besides, because there is no low temperature restriction in our model, we are able to determine the composition of clathrate hydrates formed at temperatures corresponding to the extreme ones measured in the polar caps. Our results show that methane enriched clathrate hydrates could be stable in the subsurface of Mars only if a primitive CH4-rich atmosphere has existed or if a subsurface source of CH4 has been (or is still) present.

  4. Gas Hydrate Research Database and Web Dissemination Channel

    SciTech Connect (OSTI)

    Micheal Frenkel; Kenneth Kroenlein; V Diky; R.D. Chirico; A. Kazakow; C.D. Muzny; M. Frenkel

    2009-09-30T23:59:59.000Z

    To facilitate advances in application of technologies pertaining to gas hydrates, a United States database containing experimentally-derived information about those materials was developed. The Clathrate Hydrate Physical Property Database (NIST Standard Reference Database {number_sign} 156) was developed by the TRC Group at NIST in Boulder, Colorado paralleling a highly-successful database of thermodynamic properties of molecular pure compounds and their mixtures and in association with an international effort on the part of CODATA to aid in international data sharing. Development and population of this database relied on the development of three components of information-processing infrastructure: (1) guided data capture (GDC) software designed to convert data and metadata into a well-organized, electronic format, (2) a relational data storage facility to accommodate all types of numerical and metadata within the scope of the project, and (3) a gas hydrate markup language (GHML) developed to standardize data communications between 'data producers' and 'data users'. Having developed the appropriate data storage and communication technologies, a web-based interface for both the new Clathrate Hydrate Physical Property Database, as well as Scientific Results from the Mallik 2002 Gas Hydrate Production Research Well Program was developed and deployed at http://gashydrates.nist.gov.

  5. Effects of Hydration and Oxygen Vacancy on CO2 Adsorption and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydration and Oxygen Vacancy on CO2 Adsorption and Activation on ?-Ga2O3(100). Effects of Hydration and Oxygen Vacancy on CO2 Adsorption and Activation on ?-Ga2O3(100)....

  6. Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt

    E-Print Network [OSTI]

    Suo, Zhigang

    Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt 2014; published online 14 October 2014) Polyacrylamide hydrogels containing salt as electrolyte have of polyacrylamide hydrogel by introducing highly hydratable salts into the hydrogel. These hydrogels show enhanced

  7. NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration

    E-Print Network [OSTI]

    Bentz, Dale P.

    NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration and Microstructure Development Modeling Package. Version 3.0 Dale P. Bentz #12;NISTIR 7232 CEMHYD3D: A Three-Dimensional Cement Hydration

  8. Dynamics of biopolymers and their hydration water studied by neutron and X-ray scattering

    E-Print Network [OSTI]

    Chu, Xiang-qiang

    2010-01-01T23:59:59.000Z

    Protein functions are intimately related to their dynamics. Moreover, protein hydration water is believed to have significant influence on the dynamics of proteins. One of the evidence is that both protein and its hydration ...

  9. Experimental evidence of logarithmic relaxation in single-particle dynamics of hydrated protein molecules

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Experimental evidence of logarithmic relaxation in single-particle dynamics of hydrated protein dynamics of hydrated lysozyme powder follows a logarithmic relax- ation in the time domain. In particular

  10. Methane Hydrate Formation and Dissocation in a Partially Saturated Sand--Measurements and Observations

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.; Seol, Yongkoo; Freifeld, Barry; Taylor, Charles E.; Gupta, Arvind

    2005-03-01T23:59:59.000Z

    We performed a sequence of tests on a partially water-saturated sand sample contained in an x-ray transparent aluminum pressure vessel that is conducive to x-ray computed tomography (CT) observation. These tests were performed to gather data for estimation of thermal properties of the sand/water/gas system and the sand/hydrate/water/gas systems, as well as data to evaluate the kinetic nature of hydrate dissociation. The tests included mild thermal perturbations for the estimation of the thermal properties of the sand/water/gas system, hydrate formation, thermal perturbations with hydrate in the stability zone, hydrate dissociation through thermal stimulation, additional hydrate formation, and hydrate dissociation through depressurization with thermal stimulation. Density changes throughout the sample were observed as a result of hydrate formation and dissociation, and these processes induced capillary pressure changes that altered local water saturation.

  11. Site Selection for DOE/JIP Gas Hydrate Drilling in the Northern Gulf of Mexico

    SciTech Connect (OSTI)

    Collett, T.S. (USGS); Riedel, M. (McGill Univ., Montreal, Quebec, Canada); Cochran, J.R. (Columbia Univ., Palisades, NY); Boswell, R.M.; Kumar, Pushpendra (Oil and Natural Gas Corporation Ltd., Navi Mumbai, India); Sathe, A.V. (Oil and Natural Gas Corporation Ltd., Uttaranchal, INDIA)

    2008-07-01T23:59:59.000Z

    Studies of geologic and geophysical data from the offshore of India have revealed two geologically distinct areas with inferred gas hydrate occurrences: the passive continental margins of the Indian Peninsula and along the Andaman convergent margin. The Indian National Gas Hydrate Program (NGHP) Expedition 01 was designed to study the occurrence of gas hydrate off the Indian Peninsula and along the Andaman convergent margin with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. NGHP Expedition 01 established the presence of gas hydrates in Krishna- Godavari, Mahanadi and Andaman basins. The expedition discovered one of the richest gas hydrate accumulations yet documented (Site 10 in the Krishna-Godavari Basin), documented the thickest and deepest gas hydrate stability zone yet known (Site 17 in Andaman Sea), and established the existence of a fully-developed gas hydrate system in the Mahanadi Basin (Site 19).

  12. Analysis of the Development of Messoyakha Gas Field: A Commercial Gas Hydrate Reservoir

    E-Print Network [OSTI]

    Omelchenko, Roman 1987-

    2012-12-11T23:59:59.000Z

    the presence of gas hydrates in the Messoyakha field was not a certainty, this current study determined the undeniable presence of gas hydrates in the reservoir. This study uses four models of the Messoyakha field structure and reservoir conditions...

  13. Gas Hydrate Equilibrium Measurements for Multi-Component Gas Mixtures and Effect of Ionic Liquid Inhibitors

    E-Print Network [OSTI]

    Othman, Enas Azhar

    2014-04-07T23:59:59.000Z

    hydrate inhibition data from a newly commissioned micro bench top reactor, a high-pressure autoclave and a rocking cell. The conditions for hydrate formation for pure methane and carbon dioxide were also measured, for validation purposes. The measured data...

  14. Sulfur geochemistry of thermogenic gas hydrate and associated sediment from the Texas-Louisiana continental slope

    E-Print Network [OSTI]

    Gledhill, Dwight Kuehl

    2001-01-01T23:59:59.000Z

    Thermogenic gas hydrate and associated sediment were recovered from the northern Gulf of Mexico east of the Mississippi Canyon to investigate the interactions between gas hydrate and sedimentary sulfides. Sediment solid phase analyses included...

  15. craton, where the pattern matches that expected from the gas-hydrate model. Fur-

    E-Print Network [OSTI]

    Kilgard, Michael P.

    craton, where the pattern matches that expected from the gas-hydrate model. Fur- ther, values-lived changes in the carbon-isotopic composition of the ocean. But the gas-hydrate model avoids some

  16. New techniques for monitoring cement hydration under simulated well conditions

    SciTech Connect (OSTI)

    Luke, K.; Hall, C.; Jones, T. [Schlumberger Cambridge Research (United Kingdom); Barnes, P.; Turillas, X.; Lewis, A. [Univ. of London (United Kingdom). Birkbeck College

    1995-11-01T23:59:59.000Z

    Fourier transform infrared spectroscopy and synchrotron X-ray powder diffraction methods are described for studying cement hydration chemistry at temperatures up to 200 C, covering the normal temperature range of wellbore cementing. The methods provide complementary information on the transformation of silicate, ferrite and sulfate minerals. The thermal decomposition of the cement mineral ettringite is shown to occur at 114 C in a sealed system in contact with water. The FTIR spectrum of a well cement slurry hydrating at 150 C and 2,000 psi is analyzed. The anomalous thickening time behavior of certain cements around 75--100 C is discussed in the light of new data on the hydration of a Class G cement at 65 and 95 C, with and without retarder.

  17. Impact of admixtures on the hydration kinetics of Portland cement

    SciTech Connect (OSTI)

    Cheung, J., E-mail: Josephine.H.Cheung@grace.com [W.R. Grace, 62 Whittemore Avenue, Cambridge MA 02140 (United States); Jeknavorian, A. [W.R. Grace, 62 Whittemore Avenue, Cambridge MA 02140 (United States); Roberts, L. [Roberts Consulting Group LLC, 44 Windsor Avenue, Acton MA 01720 (United States); Silva, D. [W.R. Grace, 62 Whittemore Avenue, Cambridge MA 02140 (United States)

    2011-12-15T23:59:59.000Z

    Most concrete produced today includes either chemical additions to the cement, chemical admixtures in the concrete, or both. These chemicals alter a number of properties of cementitious systems, including hydration behavior, and it has been long understood by practitioners that these systems can differ widely in response to such chemicals. In this paper the impact on hydration of several classes of chemicals is reviewed with an emphasis on the current understanding of interactions with cement chemistry. These include setting retarders, accelerators, and water reducing dispersants. The ability of the chemicals to alter the aluminate-sulfate balance of cementitious systems is discussed with a focus on the impact on silicate hydration. As a key example of this complex interaction, unusual behavior sometimes observed in systems containing high calcium fly ash is highlighted.

  18. Protein structure and hydration probed by SANS and osmotic stress

    SciTech Connect (OSTI)

    Rau, Dr. Donald [National Institutes of Health

    2008-01-01T23:59:59.000Z

    Interactions governing protein folding, stability, recognition, and activity are mediated by hydration. Here, we use small-angle neutron scattering coupled with osmotic stress to investigate the hydration of two proteins, lysozyme and guanylate kinase (GK), in the presence of solutes. By taking advantage of the neutron contrast variation that occurs upon addition of these solutes, the number of protein-associated (solute-excluded) water molecules can be estimated from changes in both the zero-angle scattering intensity and the radius of gyration. Poly(ethylene glycol) exclusion varies with molecular weight. This sensitivity can be exploited to probe structural features such as the large internal GK cavity. For GK, small-angle neutron scattering is complemented by isothermal titration calorimetry with osmoticstress to also measure hydration changes accompanying ligand binding. These results provide a framework for studying other biomolecular systems and assemblies using neutron scattering together with osmotic stress.

  19. High-surface-area hydrated lime for SO2 control

    SciTech Connect (OSTI)

    Rostam-Abadi, M.; Moran, D.L. (Illinois State Geological Survey, Champaign, IL (United States). Minerals Engineering Section)

    1993-03-01T23:59:59.000Z

    Since 1986, the Illinois State Geological Survey (ISGS), has been developing a process to produce high-surface-area hydrated lime (HSAHL) with more activity for adsorbing SO2 than commercially available hydrated lime. HSAHL prepared by the ISGS method as considerably higher surface area and porosity, and smaller mean particle diameter and crystallite size than commercial hydrated lime. The process has been optimized in a batch, bench-scale reactor and has been scaled-up to a 20--100 lb/hr process optimization unit (POU). Experiments have been conducted to optimize the ISGS hydration process and identify key parameters influencing hydrate properties for SO2 capture (surface area, porosity, particle size, and crystallite size). The known how is available to tailor properties of hydrated limes for specific SO2 removal applications. Pilot-scale tests conducted with the HSAHL under conditions typical of burning high-sulfur coals have achieved up to 90% SO2 capture in various DSI systems. The removal results are enough to bring most high-sulfur coals into compliance with acid rain legislation goals for the year 2000. The focus of the POU program is to generate critical engineering data necessary for the private sector to scale-up the process to a commercial level and provide estimates of the optimal cost of construction and operation of a commercial plant. ISGS is currently participating in a clean coal technology program (CCT-1) by providing 50 tons of HSAHL for a demonstration test at Illinois Power's Hennepin station in January 1993.

  20. Electrical properties of polycrystalline methane hydrate Wyatt L. Du Frane,1

    E-Print Network [OSTI]

    Constable, Steve

    ). CH4 hydrate formation requires cool temperature, high pressure, and sufficient supplies of H2O and CH

  1. Oil and Gas CDT Gas hydrate distribution on tectonically active continental

    E-Print Network [OSTI]

    Henderson, Gideon

    Oil and Gas CDT Gas hydrate distribution on tectonically active continental margins: Impact on gas. Gregory F. Moore, University of Hawaii (USA) http://www.soest.hawaii.edu/moore/ Key Words Gas Hydrates, Faults, Fluid Flow, gas prospectivity Overview Fig. 1. Research on gas hydrates is often undertaken

  2. Impacts of ocean acidification and mitigative hydrated lime addition on Pacific oyster larvae

    E-Print Network [OSTI]

    Impacts of ocean acidification and mitigative hydrated lime addition on Pacific oyster larvae, and for other species. Keywords: Ocean acidification; Pacific oyster; Larval stages; Hydrated lime; Shellfish No.: 577 Title of Project: Impacts of ocean acidification and mitigative hydrated lime addition

  3. Vapour Phase Hydration of Blended Oxide Magnox Waste Glasses Neil C. Hyatt,1*

    E-Print Network [OSTI]

    Sheffield, University of

    Vapour Phase Hydration of Blended Oxide ­ Magnox Waste Glasses Neil C. Hyatt,1* William E. Lee,1 BNFL Technology Centre, Sellafield, Seascale, Cumbria, CA20 1PG. UK. ABSTRACT Vapour phase hydration across the alteration layer. Vapour phase hydration leads to formation of surface alteration products

  4. Logarithmic Decay in Single-Particle Relaxation of Hydrated Lysozyme Powder Marco Lagi,1,2

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Logarithmic Decay in Single-Particle Relaxation of Hydrated Lysozyme Powder Marco Lagi,1,2 Piero-dynamics of protein amino acids of hydrated lysozyme powder around the physiological temperature by means of molecular and their hydration water display a feature known as boson peak, typical of strong glass formers [3]; (3) the protein

  5. Effect of Elevated Curing Temperature on Early Hydration and Microstructure of Composite Cements

    E-Print Network [OSTI]

    Sheffield, University of

    Effect of Elevated Curing Temperature on Early Hydration and Microstructure of Composite Cements J, Seascale, Cumbria, CA20 1PG, UK Abstract The heat of hydration of a number of composite cement systems has microscopy. Results showed that increasing the hydration temperature increased the rate of heat output

  6. Phonon-like excitation in secondary and tertiary structure of hydrated protein Mingda Li,a

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    Phonon-like excitation in secondary and tertiary structure of hydrated protein powders Mingda Li dispersion relations and their damping in two hydrated proteins, a-chymotrypsinogen A and casein, differing transition temperature TD: hydrated proteins are conformationally flexible and enzymatically active above TD

  7. Phase I (CATTS Theory), Phase II (Milne Point), Phase III (Hydrate Ridge)

    SciTech Connect (OSTI)

    None

    2009-10-31T23:59:59.000Z

    This study introduces a new type of â??cumulative seismic attributeâ? (CATT) which quantifies gas hydrates resources in Hydrate Ridge offshore Oregon. CATT is base on case-specific transforms that portray hydrated reservoir properties. In this study we used a theoretical rock physics model to correct measured velocity log data.

  8. Iodine as a tracer of organic material: 129 I results from gas hydrate

    E-Print Network [OSTI]

    Fehn, Udo

    Iodine as a tracer of organic material: 129 I results from gas hydrate systems and fore arc fluids of this system, investigations of gas hydrates from the Peru Margin (ODP 201, Site 1230) and of fluids collected for these fluids. The results are in good agreement with earlier investigations of gas hydrate systems at Blake

  9. Journal of Crystal Growth 250 (2003) 499515 Induction time in crystallization of gas hydrates

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    2003-01-01T23:59:59.000Z

    Journal of Crystal Growth 250 (2003) 499­515 Induction time in crystallization of gas hydrates Dimo. Kern Abstract The kinetics of the initial stage of crystallization of one-component gas hydrates of gas consumed are determined. Expressions are derived for the supersaturation dependence of the hydrate

  10. First results from a marine controlled-source electromagnetic survey to detect gas hydrates offshore Oregon

    E-Print Network [OSTI]

    Key, Kerry

    First results from a marine controlled-source electromagnetic survey to detect gas hydrates 13 December 2005; accepted 19 December 2005; published 3 February 2006. [1] Submarine gas hydrate from a marine controlled-source electromagnetic survey to detect gas hydrates offshore Oregon, Geophys

  11. ORIGINAL RESEARCH PAPER Canyon-infilling and gas hydrate occurrences in the frontal fold

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    ORIGINAL RESEARCH PAPER Canyon-infilling and gas hydrate occurrences in the frontal fold to infer the canyon-infilling, fold uplift, and gas hydrate occurrences beneath the frontal fold at the toe simu- lating reflector (BSR) on seismic sections indicates the base of gas hydrate stability zone

  12. Can gas hydrate structures be described using classical simulations? Maria M. Conde,1

    E-Print Network [OSTI]

    McBride, Carl

    Can gas hydrate structures be described using classical simulations? Maria M. Conde,1 Carlos Vega,1.1063/1.3353953 I. INTRODUCTION Gas hydrates are icelike inclusion compounds formed from a matrix of water path-integral simulations of the hydrate solid structures have been performed using the recently

  13. ORIGINAL RESEARCH PAPER Geothermal modeling of the gas hydrate stability zone

    E-Print Network [OSTI]

    ORIGINAL RESEARCH PAPER Geothermal modeling of the gas hydrate stability zone along the Krishna simulating reflector (BSR), interpreted to mark the thermally controlled base of the gas hydrate stability of the eastern continental margin of India. The seismic data reveal that gas hydrate occurs in the Krishna

  14. MODELLING GAS HYDRATE EQUILIBRIA USING THE ELECTROLYTE NON-RANDOM TWO-LIQUID (ENRTL) MODEL

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MODELLING GAS HYDRATE EQUILIBRIA USING THE ELECTROLYTE NON-RANDOM TWO-LIQUID (ENRTL) MODEL Matthias" developed in our group and allowing for performing equilibrium calculations involving gas hydrate phases of state approach for the gas phase, the van-der-Waals and Platteeuw model for the clathrate hydrate phase

  15. STRUCTURE OF A CARBONATE/HYDRATE MOUND IN THE NORTHERN GULF OF MEXICO

    E-Print Network [OSTI]

    Gerstoft, Peter

    the mound. Keywords: carbonate/hydrate mound, seismic structures, gas migration, seafloor observatorySTRUCTURE OF A CARBONATE/HYDRATE MOUND IN THE NORTHERN GULF OF MEXICO T. McGee1* , J. R. Woolsey1 of California, San Diego ABSTRACT A one-kilometer-diameter carbonate/hydrate mound in Mississippi Canyon Block

  16. Natural Gas Hydrate Particles in Oil-Free Systems with Kinetic Inhibition and Slurry Viscosity Reduction

    E-Print Network [OSTI]

    Firoozabadi, Abbas

    Natural Gas Hydrate Particles in Oil-Free Systems with Kinetic Inhibition and Slurry Viscosity, reduction of slurry viscosity, and corrosion inhibition. INTRODUCTION Water often forms gas hydrates antiagglomeration (AA) in the natural gas hydrate literature. The main limitation to application has been the need

  17. AGGLOMERATION OF GAS HYDRATE IN A WATER-IN-OIL EMULSION: EXPERIMENTAL AND MODELING STUDIES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    AGGLOMERATION OF GAS HYDRATE IN A WATER-IN-OIL EMULSION: EXPERIMENTAL AND MODELING STUDIES Ana of gas hydrates in water-in-oil emulsion is investigated at the laboratory pilot scale on a flow loop and a spread of the Chord Length Distribution (CLD) to larger chord length. Keywords: gas hydrates, flow loop

  18. A Quantum Chemistry Study of Natural Gas Hydrates Mert Atilhan,1

    E-Print Network [OSTI]

    Pala, Nezih

    1 A Quantum Chemistry Study of Natural Gas Hydrates Mert Atilhan,1 Nezih Pala,2 and Santiago to take account of dispersion. Keywords: Natural gas, hydrates, quantum chemistry, density functional theory. #12;2 INTRODUCTION Natural gas hydrates have attracted great attention both in the industry

  19. Submarine pingoes: Indicators of shallow gas hydrates in a pockmark at Nyegga, Norwegian Sea

    E-Print Network [OSTI]

    Svensen, Henrik

    Submarine pingoes: Indicators of shallow gas hydrates in a pockmark at Nyegga, Norwegian Sea Martin; Nyegga; gas hydrates; fluid flow; sediment stability; shallow gas; methane flow; porewater flow 1. Introduction It has long been known that gas hydrates hosted in oceanic low-permeable sediments have

  20. Clathrate hydrate equilibrium data for the gas mixture of carbon dioxide and nitrogen in the

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Clathrate hydrate equilibrium data for the gas mixture of carbon dioxide and nitrogen and nitrogen gas separation is achieved through clathrate hydrate formation in the presence of cyclopentane the corresponding mole fraction in the gas mixture amounts to 0.507. When compared to the three phase hydrate

  1. Application of the Cell Potential Method To Predict Phase Equilibria of Multicomponent Gas Hydrate Systems

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Application of the Cell Potential Method To Predict Phase Equilibria of Multicomponent Gas Hydrate the first documentation nearly two centuries ago,2 natural gas clathrate-hydrates, called clathrates, have at understanding and avoiding clathrate formation. More recently, natural gas hydrates have been proposed

  2. Nonexistent electron affinity of OCS and the stabilization of carbonyl sulfide anions by gas phase hydration

    E-Print Network [OSTI]

    Sanov, Andrei

    Nonexistent electron affinity of OCS and the stabilization of carbonyl sulfide anions by gas phase hydration Eric Surber, S. P. Ananthavel, and Andrei Sanova) Department of Chemistry, University of Arizona the abundance of the hydrated anions is attributed to the stabilizing effect of hydration. These conclusions

  3. VOLUME 88 NUMBER 19 8 MAY 2007 Methane hydrate is a clathrate, an ice-like

    E-Print Network [OSTI]

    Mazzini, Adriano

    ., 1999; Bouriak et al., 2000; Hovland and Svensen, 2006], the pres- ence of gas hydrate had never been are lined with hydrate and whether any free gas exists in the chimneys, and to provide evidence209 VOLUME 88 NUMBER 19 8 MAY 2007 Methane hydrate is a clathrate, an ice-like solid formed from

  4. DOI: 10.1002/chem.200901830 Hydration of Sugars in the Gas Phase: Regioselectivity and Conformational

    E-Print Network [OSTI]

    Davis, Ben G.

    DOI: 10.1002/chem.200901830 Hydration of Sugars in the Gas Phase: Regioselectivity: The influence of an acetami- do group in directing the preferred choice of hydration sites in glucosa- mine and a consequent extension of the working rules governing regioselec- tive hydration and conformational choice

  5. Methane escape from gas hydrate systems in marine environment, and methane-driven oceanic eruptions

    E-Print Network [OSTI]

    Zhang, Youxue

    Methane escape from gas hydrate systems in marine environment, and methane-driven oceanic eruptions are suitable for gas hydrate stability [Lunine and Stevenson, 1985]. Enor- mous amounts of methane are stored as gas hydrate and free gas in the pore space of marine sediment [Kvenvolden, 1988; Buffet, 2000

  6. Estimation of methane flux offshore SW Taiwan and the influence of tectonics on gas hydrate accumulation

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    Estimation of methane flux offshore SW Taiwan and the influence of tectonics on gas hydrate simulating reflectors (BSRs) imply the potential existence of gas hydrates offshore southwestern Taiwan settings in offshore SW Taiwan might strongly control the stability of gas hydrates, and thus affect

  7. Modeling the climate response to a massive methane release from gas hydrates

    E-Print Network [OSTI]

    Renssen, Hans

    Modeling the climate response to a massive methane release from gas hydrates H. Renssen and C. J release from gas hydrates, Paleoceanography, 19, PA2010, doi:10.1029/2003PA000968. 1. Introduction [2] Catastrophic releases of methane gas from hydrates (clathrates) have been mentioned to be responsible for rapid

  8. RHEOLOGICAL STUDY OF AN HYDRATE SLURRY FOR AIR CONDITIONNING APPLICATION

    E-Print Network [OSTI]

    Boyer, Edmond

    [-] INTRODUCTION In the context of the classical refrigerants phase out, phase change materials (PCM) arouse great interests. Indeed, for very low temperature application such as refrigeration, ice-slurries are spread as secondary refrigerants. Concerning hydrates, they have been used as PCM for cold storage for years

  9. Hydration and Conductivity in Natural Rubber Latex Gloves

    E-Print Network [OSTI]

    Bennett, John K.

    Hydration and Conductivity in Natural Rubber Latex Gloves John K. Bennett, PhD, PE Department of natural rubber latex (NRL) gloves have been of clinical interest since the concept of using an electrical result is that most natural rubber latex gloves have dynamic electrical behavior that precludes the use

  10. The Clinical Significance of Hydration in Natural Rubber Latex Gloves

    E-Print Network [OSTI]

    Bennett, John K.

    The Clinical Significance of Hydration in Natural Rubber Latex Gloves J. K. Bennett Department performance of natural rubber latex gloves. ffl These effects potentially include increased conductivity [6], have resulted in a dramatic increase in the use of natural rubber latex (NRL) surgical

  11. A Study of Formation and Dissociation of Gas Hydrate

    E-Print Network [OSTI]

    Badakhshan Raz, Sadegh

    2012-07-16T23:59:59.000Z

    and the chemical composition of the water had little effect on the ice and gas hydrate formation temperatures, which were in the range of -8 +/- 0.2 degrees C in all the tests using the cooling rate of 0.45 degrees C/min. In contrast, the increase in the cooling...

  12. Enhancement of Hydrogen Storage Capacity in Hydrate Lattices

    SciTech Connect (OSTI)

    Yoo, Soohaeng; Xantheas, Sotiris S.

    2012-02-16T23:59:59.000Z

    First principles electronic structure calculations of the gas phase pentagonal dodecahedron (H2O)20 (D-cage) and tetrakaidecahedron (H2O)24 (T-cage), which are building blocks of structure I (sI) hydrate lattice, suggest that these can accommodate up to a maximum of 5 and 7 guest hydrogen molecules, respectively. For the pure hydrogen hydrate, Born-Oppenheimer Molecular Dynamics (BOMD) simulations of periodic (sI) hydrate lattices indicate that the guest molecules are released into the vapor phase via the hexagonal phases of the larger T-cages. An additional mechanism for the migration between neighboring D- and T-cages was found to occur through a shared pentagonal face via the breaking and reforming of a hydrogen bond. This molecular mechanism is also found for the expulsion of a CH4 molecule from the D-cage. The presence of methane in the larger T-cages was found to block this release, therefore suggesting possible scenarios for the stabilization of these mixed guest clathrate hydrates and the potential enhancement of their hydrogen storage capacity.

  13. Production of hydrocarbons from hydrates. [DOE patent application

    DOE Patents [OSTI]

    McGuire, P.L.

    1981-09-08T23:59:59.000Z

    An economical and safe method of producing hydrocarbons (or natural gas) from in situ hydrocarbon-containing hydrates is given. Once started, the method will be self-driven and will continue producing hydrocarbons over an extended period of time (i.e., many days).

  14. Ethane enrichment and propane depletion in subsurface gases indicate gas hydrate occurrence in marine sediments at southern Hydrate Ridge offshore Oregon

    SciTech Connect (OSTI)

    Milkov, Alexei V.; Claypool, G E.; Lee, Young-Joo; Torres, Marta E.; Borowski, W S.; Tomaru, H; Sassen, Roger; Long, Philip E.

    2004-07-02T23:59:59.000Z

    The recognition of finely disseminated gas hydrate in deep marine sediments heavily depends on various indirect techniques because this mineral quickly decomposes upon recovery from in situ pressure and temperature conditions. Here, we discuss molecular properties of closely spaced gas voids (formed as a result of core recovery) and gas hydrates from an area of relatively low gas flux at the flanks of the southern Hydrate Ridge Offshore Oregon (ODP Sites 1244, 1245 and 1247).

  15. Direct Observations of Three Dimensional Growth of Hydrates Hosted in Porous Media

    SciTech Connect (OSTI)

    Kerkar, P.; Jones, K; Kleinberg, R; Lindquist, W; Tomov, S; Feng, H; Mahajan, D

    2009-01-01T23:59:59.000Z

    The visualization of time-resolved three-dimensional growth of tetrahydrofuran hydrates with glass spheres of uniform size as porous media using synchrotron x-ray computed microtomography is presented. The images of hydrate patches, formed from excess tetrahydrofuran in aqueous solution, show random nucleation and growth concomitant with grain movement but independent of container-wall effect. Away from grain surfaces, hydrate surface curvature was convex showing that liquid, not hydrate, was the wetting phase, similar to ice growth in porous media. The extension of the observed behavior to methane hydrates could have implications in understanding their role in seafloor stability and climate change.

  16. Effect of bubble size and density on methane conversion to hydrate

    SciTech Connect (OSTI)

    Leske, J.; Taylor, C.E.; Ladner, E.P.

    2007-03-01T23:59:59.000Z

    Research is underway at NETL to understand the physical properties of methane hydrates. One area of investigation is the storage of methane as methane hydrates. An economical and efficient means of storing methane in hydrates opens many commercial opportunities such as transport of stranded gas, off-peak storage of line gas, etc.We have observed during our investigations that the ability to convert methane to methane hydrate is enhanced by foaming of the methane–water solution using a surfactant. The density of the foam, along with the bubble size, is important in the conversion of methane to methane hydrate.

  17. Estimates of worldwide hydrate resources are large, but they are also uncertain because of inherent difficulties in

    E-Print Network [OSTI]

    Texas at Austin, University of

    difficulties in determining the amount of gas hydrate present in ocean sed- iments. Estimates of gas-hydrate in gas hydrates and as free gas on Blake Ridge offshore South Carolina (USA) range from about 70 trillion can partly be attributed to poor understanding of how gas hydrates are distributed in their host

  18. Comparison of Kinetic and Equilibrium Reaction Models in Simulating the Behavior of Gas Hydrates in Porous Media

    E-Print Network [OSTI]

    Kowalsky, Michael B.; Moridis, George J.

    2006-01-01T23:59:59.000Z

    hydrocarbons residing in hydrate deposits is estimated to substantially exceed all known conventional

  19. Gas Hydrate Equilibria for CO2-N2 and CO2-CH4 gas mixtures Experimental studies and Thermodynamic Modelling

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Gas Hydrate Equilibria for CO2-N2 and CO2-CH4 gas mixtures ­ Experimental studies and Thermodynamic of experimental data on the phase equilibrium of gas hydrates in the presence of binary gas mixtures comprising CO of the gas phase as well as the hydrate phase without the need to sample the hydrate. The experimental

  20. U N C L A S S I F I E D Gas Hydrate Experimental Capabilities at the Los Alamos

    E-Print Network [OSTI]

    Downs, Robert T.

    U N C L A S S I F I E D Gas Hydrate Experimental Capabilities at the Los Alamos Neutron Scattering with synthesizing gas hydrate samples and with the ex-situ synthesis apparatus. -This work has benefited from) which produces white neutron beams for time-of-flight neutron scattering. Gas hydrates ·Gas hydrates

  1. Gas Hydrate Property Measurements in Porous Sediments With Resonant Ultrasound Spectroscopy

    SciTech Connect (OSTI)

    McGrail, B. Peter; Ahmed, Salahuddin; Schaef, Herbert T.; Owen, Antionette T.; Martin, Paul (PNNL); Zhu, Tao

    2007-05-05T23:59:59.000Z

    Resonant ultrasound spectra were collected on natural geological core samples containing known amounts of water while under pressure with methane gas and cooled to sub-ambient temperatures such that methane hydrate formed in the pore space. Strong resonance peaks were observed using either compressional or shear mode transducers but only when gas hydrates were present. By using deuterated methane gas to form gas hydrate in a core sample obtained from the Mallik 5L-38 gas hydrate research well, resonance peak amplitude was conclusively shown to correlate with gas hydrate saturation. A pore water freezing model was developed that utilizes the known pore size distribution in a sample and pore water chemistry to predict gas hydrate saturations as a function of pressure and temperature. The model showed good agreement with the experimental measurements and demonstrated that pore water chemistry is the most important factor controlling equilibrium gas hydrate saturations in these sediments when gas hydrates are formed artificially in laboratory pressure vessels. With further development, the resonant ultrasound technique can provide a rapid, non-destructive, and field portable means of measuring the equilibrium P-T properties and dissociation kinetics of gas hydrates in porous media, determining gas hydrate saturations, and may provide new insights into the nature of gas hydrate formation mechanisms in geological materials.

  2. Depressurization-induced gas production from Class 1 and Class 2hydrate deposits

    SciTech Connect (OSTI)

    Moridis, George J.; Kowalsky, Michael

    2006-05-12T23:59:59.000Z

    Class 1 hydrate deposits are characterized by a Hydrate-Bearing Layer (HBL) underlain by a two-phase zone involving mobile gas. Such deposits are further divided to Class 1W (involving water and hydrate in the HBL) and Class 1G (involving gas and hydrate in the HBL). In Class 2 deposits, a mobile water zone underlies the hydrate zone. Methane is the main hydrate-forming gas in natural accumulations. Using TOUGH-FX/HYDRATE to study the depressurization-induced gas production from such deposits, we determine that large volumes of gas could be readily produced at high rates for long times using conventional technology. Dissociation in Class 1W deposits proceeds in distinct stages, but is continuous in Class 1G deposits. Hydrates are shown to contribute significantly to the production rate (up to 65 percent and 75 percent in Class 1W and 1G, respectively) and to the cumulative volume of produced gas (up to 45 percent and 54 percent in Class 1W and 1G, respectively). Large volumes of hydrate-originating CH4 could be produced from Class 2 hydrates, but a relatively long lead time would be needed before gas production (which continuously increases over time) attains a substantial level. The permeability of the confining boundaries plays a significant role in gas production from Class 2 deposits. In general, long-term production is needed to realize the full potential of the very promising Class 1 and Class 2 hydrate deposits.

  3. Hydration of gas-phase ytterbium ion complexes studied by experiment and theory

    SciTech Connect (OSTI)

    Rutkowski, Philip X; Michelini, Maria C.; Bray, Travis H.; Russo, Nino; Marcalo, Joaquim; Gibson, John K.

    2011-02-11T23:59:59.000Z

    Hydration of ytterbium (III) halide/hydroxide ions produced by electrospray ionization was studied in a quadrupole ion trap mass spectrometer and by density functional theory (DFT). Gas-phase YbX{sub 2}{sup +} and YbX(OH){sup +} (X = OH, Cl, Br, or I) were found to coordinate from one to four water molecules, depending on the ion residence time in the trap. From the time dependence of the hydration steps, relative reaction rates were obtained. It was determined that the second hydration was faster than both the first and third hydrations, and the fourth hydration was the slowest; this ordering reflects a combination of insufficient degrees of freedom for cooling the hot monohydrate ion and decreasing binding energies with increasing hydration number. Hydration energetics and hydrate structures were computed using two approaches of DFT. The relativistic scalar ZORA approach was used with the PBE functional and all-electron TZ2P basis sets; the B3LYP functional was used with the Stuttgart relativistic small-core ANO/ECP basis sets. The parallel experimental and computational results illuminate fundamental aspects of hydration of f-element ion complexes. The experimental observations - kinetics and extent of hydration - are discussed in relationship to the computed structures and energetics of the hydrates. The absence of pentahydrates is in accord with the DFT results, which indicate that the lowest energy structures have the fifth water molecule in the second shell.

  4. Methane Hydrate Formation and Dissociation in a PartiallySaturated Core-Scale Sand Sample

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.; Seol,Yongkoo; Freifeld, Barry M.; Taylor, Charles E.; Gupta, Arvind

    2005-11-03T23:59:59.000Z

    We performed a sequence of tests on a partiallywater-saturated sand sample contained in an x-ray transparent aluminumpressure vessel that is conducive to x-ray computed tomography (CT)observation. These tests were performed to gather data for estimation ofthermal properties of the sand/water/gas system and thesand/hydrate/water/gas systems, as well as data to evaluate the kineticnature of hydrate dissociation. The tests included mild thermalperturbations for the estimation of the thermal properties of thesand/water/gas system, hydrate formation, thermal perturbations withhydrate in the stability zone, hydrate dissociation through thermalstimulation, additional hydrate formation, and hydrate dissociationthrough depressurization with thermal stimulation. Density changesthroughout the sample were observed as a result of hydrate formation anddissociation, and these processes induced capillary pressure changes thataltered local water saturation.

  5. TOUGH+Hydrate v1.0 User's Manual: A Code for the Simulation of System Behavior in Hydrate-Bearing Geologic Media

    SciTech Connect (OSTI)

    Moridis, George; Moridis, George J.; Kowalsky, Michael B.; Pruess, Karsten

    2008-03-01T23:59:59.000Z

    TOUGH+HYDRATE v1.0 is a new code for the simulation of the behavior of hydrate-bearing geologic systems. By solving the coupled equations of mass and heat balance, TOUGH+HYDRATE can model the non-isothermal gas release, phase behavior and flow of fluids and heat under conditions typical of common natural CH{sub 4}-hydrate deposits (i.e., in the permafrost and in deep ocean sediments) in complex geological media at any scale (from laboratory to reservoir) at which Darcy's law is valid. TOUGH+HYDRATE v1.0 includes both an equilibrium and a kinetic model of hydrate formation and dissociation. The model accounts for heat and up to four mass components, i.e., water, CH{sub 4}, hydrate, and water-soluble inhibitors such as salts or alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice phase and hydrate phase). Hydrate dissociation or formation, phase changes and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects and inhibitor-induced effects. TOUGH+HYDRATE is the first member of TOUGH+, the successor to the TOUGH2 [Pruess et al., 1991] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRAN 95, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available.

  6. Geomechanical Performance of Hydrate-Bearing Sediments in Offshore Environments

    SciTech Connect (OSTI)

    Stephen A. Holditch

    2006-12-31T23:59:59.000Z

    The main objective of this study is to develop the necessary knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus is on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. To achieve this objective, we have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. To be sure our geomechanical modeling is realistic, we are also investigating the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. In Phase II of the project, we will review all published core data and generate additional core data to verify the models. To generate data for our models, we are using data from the literature and we will be conducting laboratory studies in 2007 that generate data to (1) evaluate the conceptual pore-scale models, (2) calibrate the mathematical models, (3) determine dominant relations and critical parameters defining the geomechanical behavior of HBS, and (4) establish relationships between the geomechanical status of HBS and the corresponding geophysical signature. The milestones for Phase I of this project are given as follows: Literature survey on typical sediments containing gas hydrates in the ocean (TAMU); Recommendations on how to create typical sediments in the laboratory (TAMU); Demonstrate that typical sediments can be created in a repeatable manner in the laboratory and gas hydrates can be created in the pore space (TAMU); Develop a conceptual pore-scale model based on available data and reports (UCB); Test the developed pore-scale concepts on simple configurations and verify the results against known measurements and observations (UCB); Complete the FLAC3D routines that will be linked with the reservoir model (LBNL); Complete the TOUGH+/HYDRATE modifications and extensions (LBNL); Complete the TOUGH+/FLAC3D interaction interface (LBNL); Integrate and test the coupled geomechanical numerical model TFxH/FLAC3D (LBNL); and Demonstrate that Petrel can be used to develop an earth model for providing data to the TOUGH+/FLAC3D (SLB).

  7. Methane hydrate formation and dissociation in a partially saturated core-scale sand sample

    SciTech Connect (OSTI)

    Kneafsey, T.J. (LBNL); Tomutsa, L. (LBNL); Moridis, G.J. (LBNL); Seol, Y. (LBNL); Freifeld, B.M. (LBNL); Taylor, C.E.; Gupta, A. (Colorado School of Mines, Golden, CO)

    2007-03-01T23:59:59.000Z

    We performed a series of experiments to provide data for validating numerical models of gas hydrate behavior in porous media. Methane hydrate was formed and dissociated under various conditions in a large X-ray transparent pressure vessel, while pressure and temperature were monitored. In addition, X-ray computed tomography (CT) was used to determine local density changes during the experiment. The goals of the experiments were to observe changes occurring due to hydrate formation and dissociation, and to collect data to evaluate the importance of hydrate dissociation kinetics in porous media. In the series of experiments, we performed thermal perturbations on the sand/water/gas system, formed methane hydrate, performed thermal perturbations on the sand/hydrate/water/gas system resulting in hydrate formation and dissociation, formed hydrate in the resulting partially dissociated system, and dissociated the hydrate by depressurization coupled with thermal stimulation. Our CT work shows significant water migration in addition to possible shifting of mineral grains in response to hydrate formation and dissociation. The extensive data including pressure, temperatures at multiple locations, and density from CT data is described.

  8. Experimental and Numerical Observations of Hydrate Reformation during Depressurization in a Core-Scale Reactor

    SciTech Connect (OSTI)

    Seol, Yongkoo; Myshakin, Evgeniy

    2011-01-01T23:59:59.000Z

    Gas hydrate has been predicted to reform around a wellbore during depressurization-based gas production from gas hydrate-bearing reservoirs. This process has an adverse effect on gas production rates and it requires time and sometimes special measures to resume gas flow to producing wells. Due to lack of applicable field data, laboratory scale experiments remain a valuable source of information to study hydrate reformation. In this work, we report laboratory experiments and complementary numerical simulations executed to investigate the hydrate reformation phenomenon. Gas production from a pressure vessel filled with hydrate-bearing sand was induced by depressurization with and without heat flux through the boundaries. Hydrate decomposition was monitored with a medical X-ray CT scanner and pressure and temperature measurements. CT images of the hydrate-bearing sample were processed to provide 3-dimensional data of heterogeneous porosity and phase saturations suitable for numerical simulations. In the experiments, gas hydrate reformation was observed only in the case of no-heat supply from surroundings, a finding consistent with numerical simulation. By allowing gas production on either side of the core, numerical simulations showed that initial hydrate distribution patterns affect gas distribution and flow inside the sample. This is a direct consequence of the heterogeneous pore network resulting in varying hydraulic properties of the hydrate-bearing sediment.

  9. Petrophysical Characterization and Reservoir Simulator for Methane Gas Production from Gulf of Mexico Hydrates

    SciTech Connect (OSTI)

    Kishore Mohanty; Bill Cook; Mustafa Hakimuddin; Ramanan Pitchumani; Damiola Ogunlana; Jon Burger; John Shillinglaw

    2006-06-30T23:59:59.000Z

    Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Estimates of the amounts of methane sequestered in gas hydrates worldwide are speculative and range from about 100,000 to 270,000,000 trillion cubic feet (modified from Kvenvolden, 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In this project novel techniques were developed to form and dissociate methane hydrates in porous media, to measure acoustic properties and CT properties during hydrate dissociation in the presence of a porous medium. Hydrate depressurization experiments in cores were simulated with the use of TOUGHFx/HYDRATE simulator. Input/output software was developed to simulate variable pressure boundary condition and improve the ease of use of the simulator. A series of simulations needed to be run to mimic the variable pressure condition at the production well. The experiments can be matched qualitatively by the hydrate simulator. The temperature of the core falls during hydrate dissociation; the temperature drop is higher if the fluid withdrawal rate is higher. The pressure and temperature gradients are small within the core. The sodium iodide concentration affects the dissociation pressure and rate. This procedure and data will be useful in designing future hydrate studies.

  10. Mimicking Natural Systems: Methane Hydrate Formation-Decomposition in Depleted Sediments

    SciTech Connect (OSTI)

    Eaton, M.; Jones, K; Mahajan, D

    2009-01-01T23:59:59.000Z

    We have initiated a systematic study of sediment-hydrate interaction under subsurface-mimic conditions to initially focus on marine hydrates. A major obstacle to studying natural hydrate systems has been the absence of a sophisticated mimic apparatus in which the hydrate formation phenomenon can be reproduced with precision. We have designed and constructed a bench-top unit, namely flexible integrated study of hydrates (FISH), for this purpose. The unit is fully instrumented to precisely record temperatures, pressures and changes in gas volume during absorption/evolution. The Labview software allows rapid and continuous data collection during the hydrate formation/dissociation cycle. In our integrated approach, several host sediments collected from Blake Ridge, a well-researched hydrate site, were characterized using the computed microtomography technique at Beamline X-26A of the National Synchrotron Light Source at Brookhaven National Laboratory. The characterized depleted sediments were then used to study the hydrate formation/decomposition kinetics under various pressures in the FISH unit. We report two hydrate formation methods: one under continuous methane gas-flow conditions (dynamic mode) and the other in which hydrates are formed from the dissolved gas phase by diffusion (static mode). Also reported is a depressurization method, namely the step-down pressure method, to yield gas evolution data. Data from such runs with host sediment from the deepest site (667 metres) is presented. During hydrate formation, the data reveals a temperature signature that is consistent with an exothermic hydrate formation event. In the decomposition cycle, data at various pressures was analysed to yield curves with similar slopes, suggesting a zero-order dependence. The capabilities of the FISH unit and the implications of these runs in establishing a database of sediment-hydrate kinetics and pore saturation are discussed.

  11. Imaging hydrated microbial extracellular polymers: Comparative analysis by electron microscopy

    SciTech Connect (OSTI)

    Dohnalkova, A.C.; Marshall, M. J.; Arey, B. W.; Williams, K. H.; Buck, E. C.; Fredrickson, J. K.

    2011-01-01T23:59:59.000Z

    Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryogenic electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of the hydrated bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in their collapse into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.

  12. Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy

    SciTech Connect (OSTI)

    Dohnalkova, Alice; Marshall, Matthew J.; Arey, Bruce W.; Williams, Kenneth H.; Buck, Edgar C.; Fredrickson, Jim K.

    2011-02-01T23:59:59.000Z

    Microbe-mineral and -metal interactions represent a major intersection between the biosphere and geosphere but require high-resolution imaging and analytical tools for investigating microscale associations. Electron microscopy has been used extensively for geomicrobial investigations and although used bona fide, the traditional methods of sample preparation do not preserve the native morphology of microbiological components, especially extracellular polymers. Herein, we present a direct comparative analysis of microbial interactions using conventional electron microscopy approaches of imaging at room temperature and a suite of cryo-electron microscopy methods providing imaging in the close-to-natural hydrated state. In situ, we observed an irreversible transformation of bacterial extracellular polymers during the traditional dehydration-based sample preparation that resulted in the collapse of hydrated gel-like EPS into filamentous structures. Dehydration-induced polymer collapse can lead to inaccurate spatial relationships and hence could subsequently affect conclusions regarding nature of interactions between microbial extracellular polymers and their environment.

  13. Determining the role of hydration forces in protein folding

    SciTech Connect (OSTI)

    Sorenson, J.M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry] [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Hura, G. [Univ. of California, Berkeley, CA (United States)] [Univ. of California, Berkeley, CA (United States); [Lawrence Berkeley National Lab., CA (United States). Life Sciences Div.; Soper, A.K. [Rutherford Appleton Lab., Didcot (United Kingdom). ISIS Facility] [Rutherford Appleton Lab., Didcot (United Kingdom). ISIS Facility; Pertsemlidis, A. [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Biochemistry] [Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Biochemistry; Head-Gordon, T. [Lawrence Berkeley National Lab., CA (United States)] [Lawrence Berkeley National Lab., CA (United States)

    1999-07-01T23:59:59.000Z

    One of the primary issues in protein folding is determining what forces drive folding and eventually stabilize the native state. A delicate balance exists between electrostatic forces such as hydrogen bonding and salt bridges, and the hydrophobic effect, which are present for both intramolecular protein interactions and intermolecular contributions with the surrounding aqueous environment. This article describes a combined experimental, theoretical, and computational effort to show how the complexity of aqueous hydration can influence the structure, folding and aggregation, and stability of model protein systems. The unification of the theoretical and experimental work is the development or discovery of effective amino acid interactions that implicitly include the effects of aqueous solvent. The authors show that consideration of the full range of complexity of aqueous hydration forces such as many-body effects, long-ranged character of aqueous solvation, and the assumptions made about the degree of protein hydrophobicity can directly impact the observed structure, folding, and stability of model protein systems.

  14. Natural gas production from hydrate dissociation: An axisymmetric model

    SciTech Connect (OSTI)

    Ahmadi, G. (Clarkson Univ., Pottsdam, NY); Ji, Chuang (Clarkson Univ., Pottsdam, NY); Smith, D.H.

    2007-08-01T23:59:59.000Z

    This paper describes an axisymmetric model for natural gas production from the dissociation of methane hydrate in a confined reservoir by a depressurizing well. During the hydrate dissociation, heat and mass transfer in the reservoir are analyzed. The system of governing equations is solved by a finite difference scheme. For different well pressures and reservoir temperatures, distributions of temperature and pressure in the reservoir, as well as the natural gas production from the well are evaluated. The numerical results are compared with those obtained by a linearization method. It is shown that the gas production rate is a sensitive function of well pressure. The simulation results are compared with the linearization approach and the shortcomings of the earlier approach are discussed.

  15. Selection of hydrate suppression methods for gas streams

    SciTech Connect (OSTI)

    Behrens, S.D.; Covington, K.K.; Collie, J.T. III

    1999-07-01T23:59:59.000Z

    This paper will discuss and compare the methods used to suppress hydrate formation in natural gas streams. Included in the comparison will be regenerated systems using ethylene glycol and non-regenerated systems using methanol. A comparison will be made between the quantities of methanol and ethylene glycol required to achieve a given a suppression. A discussion of BTEX emissions resulting from the ethylene glycol regenerator along with the effect or process variables on these emissions is also given.

  16. Anomalous dynamics of confined water at low hydration

    E-Print Network [OSTI]

    P. Gallo; M. Rovere

    2003-11-12T23:59:59.000Z

    The mobility of water molecules confined in a silica pore is studied by computer simulation in the low hydration regime, where most of the molecules reside close to the hydrophilic substrate. A layer analysis of the single particle dynamics of these molecules shows an anomalous diffusion with a sublinear behaviour at long time. This behaviour is strictly connected to the long time decay of the residence time distribution analogously to water at contact with proteins.

  17. Quasi-Chemical and Structural Analysis of Polarizable Anion Hydration

    E-Print Network [OSTI]

    David M. Rogers; Thomas L. Beck

    2009-12-14T23:59:59.000Z

    Quasi-chemical theory is utilized to analyze the roles of solute polarization and size in determining the structure and thermodynamics of bulk anion hydration for the Hofmeister series Cl$^-$, Br$^-$, and I$^-$. Excellent agreement with experiment is obtained for whole salt hydration free energies using the polarizable AMOEBA force field. The quasi-chemical approach exactly partitions the solvation free energy into inner-shell, outer-shell packing, and outer-shell long-ranged contributions by means of a hard-sphere condition. Small conditioning radii, even well inside the first maximum of the ion-water(oxygen) radial distribution function, result in Gaussian behavior for the long-ranged contribution that dominates the ion hydration free energy. The spatial partitioning allows for a mean-field treatment of the long-ranged contribution, leading to a natural division into first-order electrostatic, induction, and van der Waals terms. The induction piece exhibits the strongest ion polarizability dependence, while the larger-magnitude first-order electrostatic piece yields an opposing but weaker polarizability dependence. In addition, a structural analysis is performed to examine the solvation anisotropy around the anions. As opposed to the hydration free energies, the solvation anisotropy depends more on ion polarizability than on ion size: increased polarizability leads to increased anisotropy. The water dipole moments near the ion are similar in magnitude to bulk water, while the ion dipole moments are found to be significantly larger than those observed in quantum mechanical studies. Possible impacts of the observed over-polarization of the ions on simulated anion surface segregation are discussed.

  18. Variability of the methane trapping in martian subsurface clathrate hydrates

    E-Print Network [OSTI]

    Thomas, Caroline; Picaud, Sylvain; Ballenegger, Vincent

    2008-01-01T23:59:59.000Z

    Recent observations have evidenced traces of methane CH4 heterogeneously distributed in the martian atmosphere. However, because the lifetime of CH4 in the atmosphere of Mars is estimated to be around 300-600 years on the basis of photochemistry, its release from a subsurface reservoir or an active primary source of methane have been invoked in the recent literature. Among the existing scenarios, it has been proposed that clathrate hydrates located in the near subsurface of Mars could be at the origin of the small quantities of the detected CH4. Here, we accurately determine the composition of these clathrate hydrates, as a function of temperature and gas phase composition, by using a hybrid statistical thermodynamic model based on experimental data. Compared to other recent works, our model allows us to calculate the composition of clathrate hydrates formed from a more plausible composition of the martian atmosphere by considering its main compounds, i.e. carbon dioxyde, nitrogen and argon, together with met...

  19. Order and disorder in calcium–silicate–hydrate

    SciTech Connect (OSTI)

    Bauchy, M., E-mail: bauchy@mit.edu [Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); MIT-CNRS Joint Laboratory at Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Qomi, M. J. Abdolhosseini; Ulm, F.-J. [Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Pellenq, R. J.-M. [Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); MIT-CNRS Joint Laboratory at Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Centre Interdisciplinaire des Nanosciences de Marseille, CNRS and Aix-Marseille University, Campus de Luminy, 13288 Marseille Cedex 09 (France)

    2014-06-07T23:59:59.000Z

    Despite advances in the characterization and modeling of cement hydrates, the atomic order in Calcium–Silicate–Hydrate (C–S–H), the binding phase of cement, remains an open question. Indeed, in contrast to the former crystalline model, recent molecular models suggest that the nanoscale structure of C–S–H is amorphous. To elucidate this issue, we analyzed the structure of a realistic simulated model of C–S–H, and compared the latter to crystalline tobermorite, a natural analogue of C–S–H, and to an artificial ideal glass. The results clearly indicate that C–S–H appears as amorphous, when averaged on all atoms. However, an analysis of the order around each atomic species reveals that its structure shows an intermediate degree of order, retaining some characteristics of the crystal while acquiring an overall glass-like disorder. Thanks to a detailed quantification of order and disorder, we show that, while C–S–H retains some signatures of a tobermorite-like layered structure, hydrated species are completely amorphous.

  20. Adiabatic Heat of Hydration Calorimetric Measurements for Reference Saltstone Waste

    SciTech Connect (OSTI)

    Bollinger, James

    2006-01-12T23:59:59.000Z

    The production of nuclear materials for weapons, medical, and space applications from the mid-1950's through the late-1980's at the Savannah River Site (SRS) generated approximately 35 million gallons of liquid high-level radioactive waste, which is currently being processed into vitrified glass for long-term storage. Upstream of the vitrification process, the waste is separated into three components: high activity insoluble sludge, high activity insoluble salt, and very low activity soluble salts. The soluble salt represents 90% of the 35 million gallons of overall waste and is processed at the SRS Saltstone Facility, where it mixed with cement, blast furnace slag, and flyash, creating a grout-like mixture. The resulting grout is pumped into aboveground storage vaults, where it hydrates into concrete monoliths, called saltstone, thus immobilizing the low-level radioactive salt waste. As the saltstone hydrates, it generates heat that slowly diffuses out of the poured material. To ensure acceptable grout properties for disposal and immobilization of the salt waste, the grout temperature must not exceed 95 C during hydration. Adiabatic calorimetric measurements of the heat generated for a representative sample of saltstone were made to determine the time-dependent heat source term. These measurements subsequently were utilized as input to a numerical conjugate heat transfer model to determine the expected peak temperatures for the saltstone vaults.

  1. More than one dynamic crossover in protein hydration water

    E-Print Network [OSTI]

    Marco G. Mazza; Kevin Stokely; Sara E. Pagnotta; Fabio Bruni; H. Eugene Stanley; Giancarlo Franzese

    2011-08-06T23:59:59.000Z

    Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network.

  2. Gas Production from Hydrate-Bearing Sediments - Emergent Phenomena -

    SciTech Connect (OSTI)

    Jung, J.W. [Georgia Institute of Technology; Jang, J.W. [Georgia Institute of Technology; Tsouris, Costas [ORNL; Phelps, Tommy Joe [ORNL; Rawn, Claudia J [ORNL; Santamarina, Carlos [Georgia Institute of Technology

    2012-01-01T23:59:59.000Z

    Even a small fraction of fine particles can have a significant effect on gas production from hydrate-bearing sediments and sediment stability. Experiments were conducted to investigate the role of fine particles on gas production using a soil chamber that allows for the application of an effective stress to the sediment. This chamber was instrumented to monitor shear-wave velocity, temperature, pressure, and volume change during CO{sub 2} hydrate formation and gas production. The instrumented chamber was placed inside the Oak Ridge National Laboratory Seafloor Process Simulator (SPS), which was used to control the fluid pressure and temperature. Experiments were conducted with different sediment types and pressure-temperature histories. Fines migrated within the sediment in the direction of fluid flow. A vuggy structure formed in the sand; these small cavities or vuggs were precursors to the development of gas-driven fractures during depressurization under a constant effective stress boundary condition. We define the critical fines fraction as the clay-to-sand mass ratio when clays fill the pore space in the sand. Fines migration, clogging, vugs, and gas-driven fracture formation developed even when the fines content was significantly lower than the critical fines fraction. These results show the importance of fines in gas production from hydrate-bearing sediments, even when the fines content is relatively low.

  3. Additives and method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, E.D. Jr.; Christiansen, R.L.; Lederhos, J.P.; Long, J.P.; Panchalingam, V.; Du, Y.; Sum, A.K.W.

    1997-06-17T23:59:59.000Z

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hindrance and/or charge repulsion. Also, polymers having an amide on which a C{sub 1}-C{sub 4} group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  4. Additives and method for controlling clathrate hydrates in fluid systems

    DOE Patents [OSTI]

    Sloan, Jr., Earle Dendy (Golden, CO); Christiansen, Richard Lee (Littleton, CO); Lederhos, Joseph P. (Wheatridge, CO); Long, Jin Ping (Dallas, TX); Panchalingam, Vaithilingam (Lakewood, CO); Du, Yahe (Golden, CO); Sum, Amadeu Kun Wan (Golden, CO)

    1997-01-01T23:59:59.000Z

    Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness. Polymers having at least some repeating units representative of polymerizing at least one of an oxazoline, an N-substituted acrylamide and an N-vinyl alkyl amide are preferred.

  5. Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

    SciTech Connect (OSTI)

    Rees, E.V.L.; Kneafsey, T.J.; Seol, Y.

    2010-07-01T23:59:59.000Z

    To study physical properties of methane gas hydrate-bearing sediments, it is necessary to synthesize laboratory samples due to the limited availability of cores from natural deposits. X-ray computed tomography (CT) and other observations have shown gas hydrate to occur in a number of morphologies over a variety of sediment types. To aid in understanding formation and growth patterns of hydrate in sediments, methane hydrate was repeatedly formed in laboratory-packed sand samples and in a natural sediment core from the Mount Elbert Stratigraphic Test Well. CT scanning was performed during hydrate formation and decomposition steps, and periodically while the hydrate samples remained under stable conditions for up to 60 days. The investigation revealed the impact of water saturation on location and morphology of hydrate in both laboratory and natural sediments during repeated hydrate formations. Significant redistribution of hydrate and water in the samples was observed over both the short and long term.

  6. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    SciTech Connect (OSTI)

    Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswell, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.

    2010-11-01T23:59:59.000Z

    The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas hydrate petroleum system, to discuss advances, requirement and suggested practices in gas hydrate (GH) prospecting and GH deposit characterization, and to review the associated technical, economic and environmental challenges and uncertainties, including: the accurate assessment of producible fractions of the GH resource, the development of methodologies for identifying suitable production targets, the sampling of hydrate-bearing sediments and sample analysis, the analysis and interpretation of geophysical surveys of GH reservoirs, well testing methods and interpretation of the results, geomechanical and reservoir/well stability concerns, well design, operation and installation, field operations and extending production beyond sand-dominated GH reservoirs, monitoring production and geomechanical stability, laboratory investigations, fundamental knowledge of hydrate behavior, the economics of commercial gas production from hydrates, and the associated environmental concerns.

  7. Salinity-induced hydrate dissociation: A mechanism for recent CH4 release on Mars

    SciTech Connect (OSTI)

    Madden, Megan Elwood [ORNL; Ulrich, Shannon M [ORNL; Onstott, Tullis [Princeton University; Phelps, Tommy Joe [ORNL

    2007-01-01T23:59:59.000Z

    Recent observations of CH4 in the Martian atmosphere suggest that CH4 has been added relatively recently. Several mechanisms for recent CH4 release have been proposed including subsurface biological methanogenesis, abiogenic hydrothermal and/or volcanic activity, dissociation of CH4 hydrates, atmospheric photolysis, or addition of organics via bolide impact. This study examines the effects of increasing salinity on gas hydrate stability and compares estimates of the Martian geothermal gradient to CH4 and CO2 hydrate stability fields in the presence of high salinity brines. The results demonstrate that salinity increases alone result in a significant decrease in the predicted hydrate stability zone within the Martian subsurface and may be a driving force in CH4 hydrate destabilization. Active thermal and/or pressure fluctuations are not required in order for CH4 hydrates to be the source of atmospheric CH4.

  8. Integrated Geologic and Geophysical Assessment of the Eileen Gas Hydrate Accumulation, North Slope, Alaska

    SciTech Connect (OSTI)

    Timothy S. Collett; David J. Taylor; Warren F. Agena; Myung W. Lee; John J. Miller; Margarita Zyrianova

    2005-04-30T23:59:59.000Z

    Using detailed analysis and interpretation of 2-D and 3-D seismic data, along with modeling and correlation of specially processed log data, a viable methodology has been developed for identifying sub-permafrost gas hydrate prospects within the Gas Hydrate Stability Zone (HSZ) and associated ''sub-hydrate'' free gas prospects in the Milne Point area of northern Alaska (Figure 1). The seismic data, in conjunction with modeling results from a related study, was used to characterize the conditions under which gas hydrate prospects can be delineated using conventional seismic data, and to analyze reservoir fluid properties. Monte Carlo style gas hydrate volumetric estimates using Crystal Ball{trademark} software to estimate expected in-place reserves shows that the identified prospects have considerable potential as gas resources. Future exploratory drilling in the Milne Point area should provide answers about the producibility of these shallow gas hydrates.

  9. A multi-phase, micro-dispersion reactor for the continuous production of methane gas hydrate

    SciTech Connect (OSTI)

    Taboada Serrano, Patricia L [ORNL; Ulrich, Shannon M [ORNL; Szymcek, Phillip [ORNL; McCallum, Scott [Oak Ridge Associated Universities (ORAU); Phelps, Tommy Joe [ORNL; Palumbo, Anthony Vito [ORNL; Tsouris, Costas [ORNL

    2009-01-01T23:59:59.000Z

    A continuous-jet hydrate reactor originally developed to generate a CO2 hydrate stream has been modified to continuously produce CH4 hydrate. The reactor has been tested in the Seafloor Process Simulator (SPS), a 72-L pressure vessel available at Oak Ridge National Laboratory. During experiments, the reactor was submerged in water inside the SPS and received water from the surrounding through a submersible pump and CH4 externally through a gas booster pump. Thermodynamic conditions in the hydrate stability regime were employed in the experiments. The reactor produced a continuous stream of CH4 hydrate, and based on pressure values and amount of gas injected, the conversion of gas to hydrate was estimated. A conversion of up to 70% was achieved using this reactor.

  10. Four Critical Needs to Change the Hydrate Energy Paradigm from Assessment to Production: The 2007 Report to Congress by the U.S. Federal methane Hydrate Advisory Committee

    SciTech Connect (OSTI)

    Mahajan,D.; Sloan, D.; Brewer, P.; Dutta, N.; Johnson, A.; Jones, E.; Juenger, K.; Kastner, M.; Masutani, S.; Swenson, R.; Whelan, J.; Wilson, s.; Woolsey, R.

    2009-03-11T23:59:59.000Z

    This work summarizes a two-year study by the U.S. Federal Methane Hydrate Advisory Committee recommending the future needs for federally-supported hydrate research. The Report was submitted to the US Congress on August 14, 2007 and includes four recommendations regarding (a) permafrost hydrate production testing, (b) marine hydrate viability assessment (c) climate effect of hydrates, and (d) international cooperation. A secure supply of natural gas is a vital goal of the U.S. national energy policy because natural gas is the cleanest and most widely used of all fossil fuels. The inherent cleanliness of natural gas, with the lowest CO2 emission per unit of heat energy of any fossil fuel, means substituting gas for coal and fuel oil will reduce emissions that can exacerbate the greenhouse effect. Both a fuel and a feedstock, a secure and reasonably priced supply of natural gas is important to industry, electric power generators, large and small commercial enterprises, and homeowners. Because each volume of solid gas hydrate contains as much as 164 standard volumes of methane, hydrates can be viewed as a concentrated form of natural gas equivalent to compressed gas but less concentrated than liquefied natural gas (LNG). Natural hydrate accumulations worldwide are estimated to contain 700,000 TCF of natural gas, of which 200,000 TCF are located within the United States. Compared with the current national annual consumption of 22 TCF, this estimate of in-place gas in enormous. Clearly, if only a fraction of the hydrated methane is recoverable, hydrates could constitute a substantial component of the future energy portfolio of the Nation (Figure 1). However, recovery poses a major technical and commercial challenge. Such numbers have sparked interest in natural gas hydrates as a potential, long-term source of energy, as well as concerns about any potential impact the release of methane from hydrates might have on the environment. Energy-hungry countries such as India and Japan are outspending the United States on hydrate science and engineering R&D by a factor of 10, and may bring this resource to market as much as a decade before the United States.

  11. CO2 Hydrate: Synthesis, Composition, Structure, Dissociation Behavior, and a Comparison to Structure I CH4 Hydrate

    SciTech Connect (OSTI)

    Circone, S. [U.S. Geological Survey, Menlo Park, CA; Stern, Laura A. [U.S. Geological Survey, Menlo Park, CA; Kirby, Stephen H. [U.S. Geological Survey, Menlo Park, CA; Durham, william B. [U.S. Geological Survey, Menlo Park, CA; Chakoumakos, Bryan C [ORNL; Rawn, Claudia J [ORNL; Rondinone, Adam Justin [ORNL; Ishii, Yoshinobu [Japan Atomic Energy Agency (JAEA)

    2003-01-01T23:59:59.000Z

    Structure I (sI) carbon dioxide (CO{sub 2}) hydrate exhibits markedly different dissociation behavior from sI methane (CH{sub 4}) hydrate in experiments in which equilibrated samples at 0.1 MPa are heated isobarically at 13 K/h from 210 K through the H{sub 2}O melting point (273.15 K). The CO{sub 2} hydrate samples release only about 3% of their gas content up to temperatures of 240 K, which is 22 K above the hydrate phase boundary. Up to 20% is released by 270 K, and the remaining CO{sub 2} is released at 271.0 {+-} 0.5 K, where the sample temperature is buffered until hydrate dissociation ceases. This reproducible buffering temperature for the dissociation reaction CO{sub 2}{center_dot}nH{sub 2}O = CO{sub 2}(g) + nH{sub 2}O(l to s) is measurably distinct from the pure H{sub 2}O melting point at 273.15 K, which is reached as gas evolution ceases. In contrast, when sI CH{sub 4} hydrate is heated at the same rate at 0.1 MPa, >95% of the gas is released within 25 K of the equilibrium temperature (193 K at 0.1 MPa). In conjunction with the dissociation study, a method for efficient and reproducible synthesis of pure polycrystalline CO{sub 2} hydrate with suitable characteristics for material properties testing was developed, and the material was characterized. CO{sub 2} hydrate was synthesized from CO{sub 2} liquid and H{sub 2}O solid and liquid reactants at pressures between 5 and 25 MPa and temperatures between 250 and 281 K. Scanning electron microscopy (SEM) examination indicates that the samples consist of dense crystalline hydrate and 50--300 {mu}m diameter pores that are lined with euhedral cubic hydrate crystals. Deuterated hydrate samples made by this same procedure were analyzed by neutron diffraction at temperatures between 4 and 215 K; results confirm that complete conversion of water to hydrate has occurred and that the measured unit cell parameter and thermal expansion are consistent with previously reported values. On the basis of measured weight gain after synthesis and gas yields from the dissociation experiments, approximately all cages in the hydrate structure are filled such that n {approx} 5.75.

  12. Methane hydrate formation in turbidite sediments of northern Cascadia IODP Expedition 311

    SciTech Connect (OSTI)

    Torres, M. E.; Trehu, Ann M.; cespedes, N.; Kastner, Miriam; Wortmann, Ulrich; Kim, J.; Long, Philip E.; Malinverno, Alberto; Pohlman, J. W.; Collett, T. S.

    2008-07-15T23:59:59.000Z

    Expedition 311 of the Integrated Ocean Drilling Program (IODP) to northern Cascadia recovered gas-hydrate bearing sediments along a SW–NE transect from the first ridge of the accretionary margin to the eastward limit of gas-hydrate stability. In this study we contrast the gas gas-hydrate distribution from two sites drilled ~8 km apart in different tectonic settings. At Site U1325, drilled on a depositional basin with nearly horizontal sedimentary sequences, the gas-hydrate distribution shows a trend of increasing saturation toward the base of gas-hydrate stability, consistent with several model simulations in the literature. Site U1326 was drilled on an uplifted ridge characterized by faulting, which has likely experienced some mass wasting events. Here the gas hydrate does not show a clear depth-distribution trend, the highest gas-hydrate saturation occurs well within the gas-hydrate stability zone at the shallow depth of ~49 mbsf. Sediments at both sites are characterized by abundant coarse-grained (sand) layers up to 23 cm in thickness, and are interspaced within fine-grained (clay and silty clay) detrital sediments. The gas-hydrate distribution is punctuated by localized depth intervals of high gas-hydrate saturation, which preferentially occur in the coarse-grained horizons and occupy up to 60% of the pore space at Site U1325 and N80% at Site U1326. Detailed analyses of contiguous samples of different lithologies show that when enough methane is present, about 90% of the variance in gas-hydrate saturation can be explained by the sand (N63 ?m) content of the sediments. The variability in gas-hydrate occupancy of sandy horizons at Site U1326 reflects an insufficient methane supply to the sediment section between 190 and 245 mbsf.

  13. Electrical Resistivity Investigation of Gas Hydrate Distribution in Mississippi Canyon Block 118, Gulf of Mexico

    SciTech Connect (OSTI)

    Dunbar, John

    2012-12-31T23:59:59.000Z

    Electrical methods offer a geophysical approach for determining the sub-bottom distribution of hydrate in deep marine environments. Methane hydrate is essentially non-conductive. Hence, sediments containing hydrate are more resistive than sediments without hydrates. To date, the controlled source electromagnetic (CSEM) method has been used in marine hydrates studies. This project evaluated an alternative electrical method, direct current resistivity (DCR), for detecting marine hydrates. DCR involves the injection of direct current between two source electrodes and the simultaneous measurement of the electric potential (voltage) between multiple receiver electrodes. The DCR method provides subsurface information comparable to that produced by the CSEM method, but with less sophisticated instrumentation. Because the receivers are simple electrodes, large numbers can be deployed to achieve higher spatial resolution. In this project a prototype seafloor DCR system was developed and used to conduct a reconnaissance survey at a site of known hydrate occurrence in Mississippi Canyon Block 118. The resulting images of sub-bottom resistivities indicate that high-concentration hydrates at the site occur only in the upper 50 m, where deep-seated faults intersect the seafloor. Overall, there was evidence for much less hydrate at the site than previously thought based on available seismic and CSEM data alone.

  14. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    E-Print Network [OSTI]

    Moridis, G.J.

    2011-01-01T23:59:59.000Z

    Of Gulf Of Mexico Sediments. Mar. Pet. Geo. 23: 893- Yun,of Mexico sediments with and without THF hydrates. Mar. Pet.

  15. Thermal dissociation behavior and dissociation enthalpies of methane-carbon dioxide mixed hydrates

    SciTech Connect (OSTI)

    Kwon, T.H.; Kneafsey, T.J.; Rees, E.V.L.

    2011-02-15T23:59:59.000Z

    Replacement of methane with carbon dioxide in hydrate has been proposed as a strategy for geologic sequestration of carbon dioxide (CO{sub 2}) and/or production of methane (CH{sub 4}) from natural hydrate deposits. This replacement strategy requires a better understanding of the thermodynamic characteristics of binary mixtures of CH{sub 4} and CO{sub 2} hydrate (CH{sub 4}-CO{sub 2} mixed hydrates), as well as thermophysical property changes during gas exchange. This study explores the thermal dissociation behavior and dissociation enthalpies of CH{sub 4}-CO{sub 2} mixed hydrates. We prepared CH{sub 4}-CO{sub 2} mixed hydrate samples from two different, well-defined gas mixtures. During thermal dissociation of a CH{sub 4}-CO{sub 2} mixed hydrate sample, gas samples from the head space were periodically collected and analyzed using gas chromatography. The changes in CH{sub 4}-CO{sub 2} compositions in both the vapor phase and hydrate phase during dissociation were estimated based on the gas chromatography measurements. It was found that the CO{sub 2} concentration in the vapor phase became richer during dissociation because the initial hydrate composition contained relatively more CO{sub 2} than the vapor phase. The composition change in the vapor phase during hydrate dissociation affected the dissociation pressure and temperature; the richer CO{sub 2} in the vapor phase led to a lower dissociation pressure. Furthermore, the increase in CO{sub 2} concentration in the vapor phase enriched the hydrate in CO{sub 2}. The dissociation enthalpy of the CH{sub 4}-CO{sub 2} mixed hydrate was computed by fitting the Clausius-Clapeyron equation to the pressure-temperature (PT) trace of a dissociation test. It was observed that the dissociation enthalpy of the CH{sub 4}-CO{sub 2} mixed hydrate lays between the limiting values of pure CH{sub 4} hydrate and CO{sub 2} hydrate, increasing with the CO{sub 2} fraction in the hydrate phase.

  16. Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

    SciTech Connect (OSTI)

    McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.

    2007-09-01T23:59:59.000Z

    Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate

  17. Depressurization-induced gas production from Class 1 and Class 2hydrate deposits

    SciTech Connect (OSTI)

    Moridis, George J.; Kowalsky, Michael

    2006-05-12T23:59:59.000Z

    Class 1 hydrate deposits are characterized by aHy-drate-Bearing Layer (HBL) underlain by a two-phase zone involvingmobile gas. Such deposits are further divided to Class 1W (involvingwater and hydrate in the HBL) and Class 1G (involving gas and hydrate inthe HBL). In Class 2 deposits, a mobile water zone underlies the hydratezone. Methane is the main hydrate-forming gas in natural accumulations.Using TOUGH-FX/HYDRATE to study the depressurization-induced gasproduction from such deposits, we determine that large volumes of gascould be readily produced at high rates for long times using conventionaltechnology. Dissociation in Class 1W deposits proceeds in distinctstages, but is continuous in Class 1G deposits. Hydrates are shown tocontribute significantly to the production rate (up to 65 percent and 75percent in Class 1W and 1G, respectively) and to the cumulative volume ofproduced gas (up to 45 percent and 54 percent in Class 1W and 1G,respectively). Large volumes of hydrate-originating CH4 could be producedfrom Class 2 hydrates, but a relatively long lead time would be neededbefore gas production (which continuously increases over time) attains asubstantial level. The permeability of the confining boundaries plays asignificant role in gas production from Class 2 deposits. In general,long-term production is needed to realize the full potential of the verypromising Class 1 and Class 2 hydrate deposits.

  18. Studies of Reaction Kinetics of Methane Hydrate Dissocation in Porous Media

    SciTech Connect (OSTI)

    Moridis, George J.; Seol, Yongkoo; Kneafsey, Timothy J.

    2005-03-10T23:59:59.000Z

    The objective of this study is the description of the kinetic dissociation of CH4-hydrates in porous media, and the determination of the corresponding kinetic parameters. Knowledge of the kinetic dissociation behavior of hydrates can play a critical role in the evaluation of gas production potential of gas hydrate accumulations in geologic media. We analyzed data from a sequence of tests of CH4-hydrate dissociation by means of thermal stimulation. These tests had been conducted on sand cores partially saturated with water, hydrate and CH4 gas, and contained in an x-ray-transparent aluminum pressure vessel. The pressure, volume of released gas, and temperature (at several locations within the cores) were measured. To avoid misinterpreting local changes as global processes, x-ray computed tomography scans provided accurate images of the location and movement of the reaction interface during the course of the experiments. Analysis of the data by means of inverse modeling (history matching ) provided estimates of the thermal properties and of the kinetic parameters of the hydration reaction in porous media. Comparison of the results from the hydrate-bearing porous media cores to those from pure CH4-hydrate samples provided a measure of the effect of the porous medium on the kinetic reaction. A tentative model of composite thermal conductivity of hydrate-bearing media was also developed.

  19. Coupled flow and geomechanical analysis for gas production in the Prudhoe Bay Unit L-106 well Unit C gas hydrate deposit in Alaska

    E-Print Network [OSTI]

    Kim, J.

    2014-01-01T23:59:59.000Z

    2009. Toward Production From Gas Hydrates: Current Status,Geologic Controls on Gas Hydrate Occurrence in the MountCollett T.S. 1993. Natural Gas Hydrates of the Prudhoe Bay

  20. Estimating the upper limit of gas production from Class 2 hydrate accumulations in the permafrost: 2. Alternative well designs and sensitivity analysis

    E-Print Network [OSTI]

    Moridis, G.

    2011-01-01T23:59:59.000Z

    m). As in all cases of gas hydrates (Moridis et al. , 2007;by destroying the secondary gas hydrate barrier (if such aInduced Gas Production From Class 1 Hydrate Deposits,” SPE

  1. Improved evidence for the existence of an intermediate phase during hydration of tricalcium silicate

    SciTech Connect (OSTI)

    Bellmann, Frank, E-mail: frank.bellmann@uni-weimar.d [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany); Damidot, Denis [Ecole des Mines de Douai, Civil and Environmental Engineering Department, 941 rue Charles Bourseul, BP 10838, 59508 Doua cedexi (France); Moeser, Bernd [Institute for Building Materials Science, Bauhaus University Weimar, 99423 Weimar (Germany); Skibsted, Jorgen [Instrument Center for Solid-State NMR Spectroscopy and Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University DK-8000 Aarhus C (Denmark)

    2010-06-15T23:59:59.000Z

    Tricalcium silicate (Ca{sub 3}SiO{sub 5}) with a very small particle size of approximately 50 nm has been prepared and hydrated for a very short time (5 min) by two different modes in a paste experiment, using a water/solid-ratio of 1.20, and by hydration as a suspension employing a water/solid-ratio of 4000. A phase containing uncondensed silicate monomers close to hydrogen atoms (either hydroxyl groups or water molecules) was formed in both experiments. This phase is distinct from anhydrous tricalcium silicate and from the calcium-silicate-hydrate (C-S-H) phase, commonly identified as the hydration product of tricalcium silicate. In the paste experiment, approximately 79% of silicon atoms were present in the hydrated phase containing silicate monomers as determined from {sup 29}Sileft brace{sup 1}Hright brace CP/MAS NMR. This result is used to show that the hydrated silicate monomers are part of a separate phase and that they cannot be attributed to a hydroxylated surface of tricalcium silicate after contact with water. The phase containing hydrated silicate monomers is metastable with respect to the C-S-H phase since it transforms into the latter in a half saturated calcium hydroxide solution. These data is used to emphasize that the hydration of tricalcium silicate proceeds in two consecutive steps. In the first reaction, an intermediate phase containing hydrated silicate monomers is formed which is subsequently transformed into C-S-H as the final hydration product in the second step. The introduction of an intermediate phase in calculations of the early hydration of tricalcium silicate can explain the presence of the induction period. It is shown that heterogeneous nucleation on appropriate crystal surfaces is able to reduce the length of the induction period and thus to accelerate the reaction of tricalcium silicate with water.

  2. Basin scale assessment of gas hydrate dissociation in response to climate change

    SciTech Connect (OSTI)

    Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M.; Cameron-Smith, P.

    2011-07-01T23:59:59.000Z

    Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating climate. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those now occurring in the arctic and those predicted under future climate change scenarios, has only recently been investigated. Field investigations have discovered substantial methane gas plumes exiting the seafloor along the Arctic Ocean margin, and the plumes appear at depths corresponding to the upper limit of a receding gas hydrate stability zone. It has been suggested that these plumes may be the first visible signs of the dissociation of shallow hydrate deposits due to ongoing climate change in the arctic. We simulate the release of methane from oceanic deposits, including the effects of fully-coupled heat transfer, fluid flow, hydrate dissociation, and other thermodynamic processes, for systems representative of segments of the Arctic Ocean margins. The modeling encompasses a range of shallow hydrate deposits from the landward limit of the hydrate stability zone down to water depths beyond the expected range of century-scale temperature changes. We impose temperature changes corresponding to predicted rates of climate change-related ocean warming and examine the possibility of hydrate dissociation and the release of methane. The assessment is performed at local-, regional-, and basin-scales. The simulation results are consistent with the hypothesis that dissociating shallow hydrates alone can result in significant methane fluxes at the seafloor. However, the methane release is likely to be confined to a narrow region of high dissociation susceptibility, defined by depth and temperature, and that any release will be continuous and controlled, rather than explosive. This modeling also establishes the first realistic bounds for methane release along the arctic continental shelf for potential hydrate dissociation scenarios, and ongoing work may help confirm whether climate change is already impacting the stability of the vast oceanic hydrate reservoir.

  3. NATURAL GAS HYDRATES STORAGE PROJECT PHASE II. CONCEPTUAL DESIGN AND ECONOMIC STUDY

    SciTech Connect (OSTI)

    R.E. Rogers

    1999-09-27T23:59:59.000Z

    DOE Contract DE-AC26-97FT33203 studied feasibility of utilizing the natural-gas storage property of gas hydrates, so abundantly demonstrated in nature, as an economical industrial process to allow expanded use of the clean-burning fuel in power plants. The laboratory work achieved breakthroughs: (1) Gas hydrates were found to form orders of magnitude faster in an unstirred system with surfactant-water micellar solutions. (2) Hydrate particles were found to self-pack by adsorption on cold metal surfaces from the micellar solutions. (3) Interstitial micellar-water of the packed particles were found to continue forming hydrates. (4) Aluminum surfaces were found to most actively collect the hydrate particles. These laboratory developments were the bases of a conceptual design for a large-scale process where simplification enhances economy. In the design, hydrates form, store, and decompose in the same tank in which gas is pressurized to 550 psi above unstirred micellar solution, chilled by a brine circulating through a bank of aluminum tubing in the tank employing gas-fired refrigeration. Hydrates form on aluminum plates suspended in the chilled micellar solution. A low-grade heat source, such as 110 F water of a power plant, circulates through the tubing bank to release stored gas. The design allows a formation/storage/decomposition cycle in a 24-hour period of 2,254,000 scf of natural gas; the capability of multiple cycles is an advantage of the process. The development costs and the user costs of storing natural gas in a scaled hydrate process were estimated to be competitive with conventional storage means if multiple cycles of hydrate storage were used. If more than 54 cycles/year were used, hydrate development costs per Mscf would be better than development costs of depleted reservoir storage; above 125 cycles/year, hydrate user costs would be lower than user costs of depleted reservoir storage.

  4. Dynamical Transition and Heterogeneous Hydration Dynamics in RNA

    E-Print Network [OSTI]

    Jeseong Yoon; Jong-Chin Lin; Changbong Hyeon; D. Thirumalai

    2014-04-24T23:59:59.000Z

    Enhanced dynamical fluctuations of RNAs, facilitated by a network of water molecules with strong interactions with RNA, are suspected to be critical in their ability to respond to a variety of cellular signals. Using atomically detailed molecular dynamics simulations at various temperatures of purine (adenine)- and preQ$_1$ sensing riboswitch aptamers, we show that water molecules in the vicinity of RNAs undergo complex dynamics depending on the local structures of the RNAs. The overall lifetimes of hydrogen bonds (HBs) of surface bound waters are more than at least 1-2 orders of magnitude longer than bulk water. Slow hydration dynamics, revealed in non-Arrhenius behavior of the relaxation time, arises from high activation barriers to break water hydrogen bonds with a nucleotide and by reduced diffusion of water. The relaxation kinetics at specific locations in the two RNAs show a broad spectrum of time scales reminiscent of glass-like behavior, suggesting that the hydration dynamics is highly heterogeneous. Both RNAs undergo dynamic transition at $T = T_D \\gtrsim 200$ K as assessed by the mean square fluctuation of hydrogen atoms $\\langle x^2\\rangle$, which undergoes an abrupt harmonic-to-anharmonic transition at $T_D$. The near universal value of $T_D$ found for these RNAs and previously for tRNA is strongly correlated with changes in hydration dynamics as $T$ is altered. Hierarchical dynamics of waters associated with the RNA surface, revealed in the motions of distinct classes of water with well-separated time scales, reflects the heterogeneous local environment on the molecular surface of RNA. At low temperatures slow water dynamics predominates over structural transitions. Our study demonstrates that the complex interplay of dynamics between water and local environment in the RNA structures could be a key determinant of the functional activities of RNA.

  5. Dynamical properties of the hydration shell of fully deuterated myoglobin

    SciTech Connect (OSTI)

    Achterhold, Klaus; Parak, Fritz G. [Physik-Department E17, Technische Universitaet Muenchen, James-Franck-Strasse 1, D-85747 Garching (Germany); Ostermann, Andreas [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), ZWE, Lichtenbergstrasse 1, D-85747 Garching (Germany); Moulin, Martine; Haertlein, Michael [ILL-EMBL Deuteration Laboratory, Partnership for Structural Biology, 6, rue Jules Horowitz, F-38042 Grenoble Cedex 9 (France); Unruh, Tobias [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), ZWE, Lichtenbergstrasse 1, D-85747 Garching (Germany); Institut fuer Physik der Kondensierten Materie, Lehrstuhl fuer Kristallographie und Strukturphysik, Staudtstrasse 3, D-91058 Erlangen (Germany)

    2011-10-15T23:59:59.000Z

    Freeze-dried perdeuterated sperm whale myoglobin was kept in a water-saturated atmosphere in order to obtain a hydration degree of 335 {sup 1}H{sub 2}O molecules per one myoglobin molecule. Incoherent neutron scattering was performed at the neutron spectrometer TOFTOF at the FRM II in an angular range of q from 0.6 to 1.8 A{sup -1} and a temperature range from 4 to 297 K. We used neutrons with a wavelength of {lambda}{alpha}E 6 A and an energy resolution of about 65 {mu}eV corresponding to motions faster than 10 ps. At temperatures above 225 K, broad lines appear in the spectra caused by quasielastic scattering. For an explanation of these lines, we assumed that there are only two types of protons, those that are part of the hydration water (72%) and those that belong to the protein (28%). The protons of the hydration water were analyzed with the diffusion model of Singwi and Sjoelander [Phys. Rev. 119, 863 (1960)]. In this model, a water molecule stays for a time {tau}{sub 0} in a bound state performing oscillatory motions. Thereafter, the molecule performs free diffusion for the time {tau}{sub 1} in a nonbound state followed again by the oscillatory motions for {tau}{sub 0} and so forth. We used the general formulation with no simplifications as {tau}{sub 0}>>{tau}{sub 1} or {tau}{sub 1}>>{tau}{sub 0}. At room temperature, we obtained {tau}{sub 0} {alpha}E 104 ps and {tau}{sub 1} {alpha}E 37 ps. For the protein bound hydrogen, the dynamics is described by a Brownian oscillator where the protons perform overdamped motions in limited space.

  6. X-ray CT Observations of Methane Hydrate Distribution Changes over Time in a Natural Sediment Core from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well

    SciTech Connect (OSTI)

    Kneafsey, T.J.; Rees, E.V.L.

    2010-03-01T23:59:59.000Z

    When maintained under hydrate-stable conditions, methane hydrate in laboratory samples is often considered a stable and immobile solid material. Currently, there do not appear to be any studies in which the long-term redistribution of hydrates in sediments has been investigated in the laboratory. These observations are important because if the location of hydrate in a sample were to change over time (e.g. by dissociating at one location and reforming at another), the properties of the sample that depend on hydrate saturation and pore space occupancy would also change. Observations of hydrate redistribution under stable conditions are also important in understanding natural hydrate deposits, as these may also change over time. The processes by which solid hydrate can move include dissociation, hydrate-former and water migration in the gas and liquid phases, and hydrate formation. Chemical potential gradients induced by temperature, pressure, and pore water or host sediment chemistry can drive these processes. A series of tests were performed on a formerly natural methane-hydrate-bearing core sample from the BPX-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well, in order to observe hydrate formation and morphology within this natural sediment, and changes over time using X-ray computed tomography (CT). Long-term observations (over several weeks) of methane hydrate in natural sediments were made to investigate spatial changes in hydrate saturation in the core. During the test sequence, mild buffered thermal and pressure oscillations occurred within the sample in response to laboratory temperature changes. These oscillations were small in magnitude, and conditions were maintained well within the hydrate stability zone.

  7. Long Range Hydration Effects in Electrolytic Free Suspended Black Films

    E-Print Network [OSTI]

    D. Sentenac; J. J. Benattar

    1998-06-16T23:59:59.000Z

    The force law within free suspended black films made of negatively charged Aerosol-OT (AOT) with added LiCl or CsCl is studied accurately using X-ray reflectivity (ca. 1{\\AA}). We find an electrolyte concentration threshold above which a substantial additional repulsion is detected in the LiCl films, up to distances of 100 {\\AA}. We interpret this phenomenon as an augmentation of the Debye screening length, due to the local screening of the condensed hydrophilic counterions by the primary hydration shell.

  8. Classification of proton configurations of gas hydrate frameworks

    SciTech Connect (OSTI)

    Kirov, M. V., E-mail: kirov@ikz.ru [Siberian Branch of the Russian Academy of Sciences, Institute of the Earth Cryosphere (Russian Federation)

    2010-05-15T23:59:59.000Z

    All molecular configurations differing in the position of hydrogen atoms (protons) in hydrogen bonds and satisfying periodic boundary conditions have been calculated for the unit cells of CS-I, HS-III, and TS-IV gas hydrate frameworks. The configurations obtained are ranged according to the number of stronger trans-configurations of hydrogen-bound molecular pairs and according to the type of spatial symmetry. The configuration symmetry was analyzed taking into account the additional antisymmetry operation, which is related to the change in the direction of all hydrogen bonds. The strong dependence of the framework properties on the specific position of protons in H bonds is established.

  9. International Cooperation in Methane Hydrates | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking ofOil & Gas » Methane Hydrate » International Cooperation in Methane

  10. Methane Hydrates and Climate Change | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742Energy China 2015of 2005 atthe District ofInstitute RegardingMethane hydrates store huge volumes

  11. Phase Equilibria Studies in Water-Methane System: Structural Memory-Effect of Water On Hydrate Re-Formation 

    E-Print Network [OSTI]

    Kim, Brice Yoonshik

    2014-12-08T23:59:59.000Z

    Naturally-occurring hydrates are promising resources. The potential value of gas accumulation in naturally-occurring gas hydrates can exceed 16 equivalent trillion tons of oil. There are many accurate findings on properties ...

  12. Assessing the Potential of Using Hydrate Technology to Capture, Store and Transport Gas for the Caribbean Region 

    E-Print Network [OSTI]

    Rajnauth, Jerome Joel

    2012-02-14T23:59:59.000Z

    natural gas as a hydrate while focusing on small scale transportation of natural gas to the Caribbean Islands. This work proposes a workflow for capturing, storing and transporting gas in the hydrate form, particularly for Caribbean situations where...

  13. Impact of hydroxypropylguars on the early age hydration1 of portland cement2

    E-Print Network [OSTI]

    Impact of hydroxypropylguars on the early age hydration1 of portland cement2 3 4 Thomas Poinot: govin@emse.fr12 hal-00758284,version1-29Nov2012 Author manuscript, published in "Cement and Concrete on cement hydration was investigated in order to improve17 understanding on the delayed effect induced

  14. HEC influence on cement hydration measured by conductometry J. Pourchez 1 *

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 HEC influence on cement hydration measured by conductometry J. Pourchez 1 * -- P. Grosseau 1 -- R-mail address: pourchez@emse.fr emse-00449716,version1-18Sep2010 Author manuscript, published in "Cement cellulose (HEMC) and hydroxypropylmethyl cellulose (HPMC) molecular parameters on cement hydration

  15. Influence of Curing Conditions on Water Loss and Hydration in Cement

    E-Print Network [OSTI]

    Bentz, Dale P.

    Influence of Curing Conditions on Water Loss and Hydration in Cement Pastes with and without Fly Loss and Hydration in Cement Pastes with and without Fly Ash Substitution Dale P. Bentz Building at different rates from portland cement, blended cements may require that special attention be paid

  16. Impact of hydroxypropylguars on the early age hydration1 of portland cement2

    E-Print Network [OSTI]

    Boyer, Edmond

    Impact of hydroxypropylguars on the early age hydration1 of portland cement2 3 4 Thomas Poinot: govin@emse.fr12 hal-00758284,version2-15Feb2013 Author manuscript, published in "Cement and Concrete on cement hydration was investigated in order to improve17 understanding on the delayed effect induced

  17. Analysis of the Development of Messoyakha Gas Field: A Commercial Gas Hydrate Reservoir 

    E-Print Network [OSTI]

    Omelchenko, Roman 1987-

    2012-12-11T23:59:59.000Z

    ). Natural gas from methane hydrate has the potential to play a major role in ensuring adequate future energy supplies in the US. The worldwide volume of gas in the hydrate state has been estimated to be approximately 1.5 x 10^16 m^3 (Makogon 1984). More than...

  18. From thorium phosphate hydrogenphosphate hydrate to -thorium phosphate diphosphate: structural evolution to a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 From thorium phosphate hydrogenphosphate hydrate to - thorium phosphate diphosphate: structural-3016" DOI : 10.1016/j.jssc.2006.05.027 #12;2 Abstract -thorium phosphate diphosphate (-TPD), considered as a very promising radwaste storage material, was obtained from thorium phosphate hydrogenphosphate hydrate

  19. Evaluation of Hydration Free Energy by Level-Set Variational Implicit-Solvent Model

    E-Print Network [OSTI]

    Li, Bo

    Evaluation of Hydration Free Energy by Level-Set Variational Implicit-Solvent Model with Coulomb free energy but also the polar and nonpolar contributions individually. The correlation between VISM-CFA and experiments is R2 = 0.763 for total hydration free energy, with a root mean square deviation (RMSD) of 1

  20. Termination and hydration of forsteritic olivine (010) surface Hongping Yan a,,1

    E-Print Network [OSTI]

    Shen, Guoyin

    Termination and hydration of forsteritic olivine (010) surface Hongping Yan a,,1 , Changyong Park a; accepted in revised form 1 September 2014; Available online 16 September 2014 Abstract Termination termination and hydration. The basic silica paste polished surface turned out too rough to measure with X

  1. Methane hydrate formation and dissociationin a partially saturatedcore-scale sand sample

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis, George J.; Seol,Yongkoo; Freifeld, Barry M.; Taylor, Charles E.; Gupta, Arvind

    2006-02-03T23:59:59.000Z

    We performed a series of experiments to provide data forvalidating numerical models of gas hydrate behavior in porous media.Methane hydrate was formed and dissociated under various conditions in alarge X-ray transparent pressure vessel, while pressure and temperaturewere monitored. In addition, X-ray computed tomography (CT) was used todetermine local density changes during the experiment. The goals of theexperiments were to observe changes occurring due to hydrate formationand dissociation, and to collect data to evaluate the importance ofhydrate dissociation kinetics in porous media. In the series ofexperiments, we performed thermal perturbations on the sand/water/gassystem, formed methane hydrate, performed thermal perturbations on thesand/hydrate/water/gas system resulting in hydrate formation anddissociation, formed hydrate in the resulting partially dissociatedsystem, and dissociated the hydrate by depressurization coupled withthermal stimulation. Our CT work shows significant water migration inaddition to possible shifting of mineral grains in response to hydrateformation and dissociation. The extensive data including pressure,temperatures at multiple locations, and density from CT data isdescribed.

  2. Development of a Numerical Simulator for Analyzing the Geomechanical Performance of Hydrate-Bearing Sediments

    SciTech Connect (OSTI)

    Rutqvist, Jonny; Rutqvist, J.; Moridis, G.J.

    2008-06-01T23:59:59.000Z

    In this paper, we describe the development and application of a numerical simulator that analyzes the geomechanical performance of hydrate-bearing sediments, which may become an important future energy supply. The simulator is developed by coupling a robust numerical simulator of coupled fluid flow, hydrate thermodynamics, and phase behavior in geologic media (TOUGH+HYDRATE) with an established geomechanical code (FLAC3D). We demonstrate the current simulator capabilities and applicability for two examples of geomechanical responses of hydrate bearing sediments during production-induced hydrate dissociation. In these applications, the coupled geomechanical behavior within hydrate-bearing seducements are considered through a Mohr-Coulomb constitutive model, corrected for changes in pore-filling hydrate and ice content, based on laboratory data. The results demonstrate how depressurization-based gas production from oceanic hydrate deposits may lead to severe geomechanical problems unless care is taken in designing the production scheme. We conclude that the coupled simulator can be used to design production strategies for optimizing production, while avoiding damaging geomechanical problems.

  3. METHANE HYDRATE STUDIES: DELINEATING PROPERTIES OF HOST SEDIMENTS TO ESTABLISH REPRODUCIBLE DECOMPOSITION KINETICS.

    SciTech Connect (OSTI)

    Mahajan, Devinder; Jones, Keith W.; Feng, Huan; Winters, William J.

    2004-12-01T23:59:59.000Z

    The use of methane hydrate as an energy source requires development of a reliable method for its extraction from its highly dispersed locations in oceanic margin sediments and permafrost. The high pressure (up to 70 MPa) and low temperature (272 K to 278 K) conditions under which hydrates are stable in the marine environment can be mimicked in a laboratory setting and several kinetic studies of pure methane hydrate decomposition have been reported. However, the effect of host sediments on methane hydrate occurrence and decomposition are required to develop reliable hydrate models. In this paper, we describe methods to measure sediment properties as they relate to pore-space methane gas hydrate. Traditional geotechnical techniques are compared to the micrometer level by use of the synchrotron Computed Microtomography (CMT) technique. CMT was used to measure the porosity at the micrometer level and to show pore-space pathways through field samples. Porosities for three sediment samples: one from a site on Georges Bank and two from the known Blake Ridge methane hydrate site, from different depths below the mud line were measured by traditional drying and by the new CMT techniques and found to be in good agreement. The integration of the two analytical approaches is necessary to enable better understanding of methane hydrate interactions with the surrounding sediment particles.

  4. Comparison of kinetic and equilibrium reaction models insimulating gas hydrate behavior in porous media

    SciTech Connect (OSTI)

    Kowalsky, Michael B.; Moridis, George J.

    2006-11-29T23:59:59.000Z

    In this study we compare the use of kinetic and equilibriumreaction models in the simulation of gas (methane) hydrate behavior inporous media. Our objective is to evaluate through numerical simulationthe importance of employing kinetic versus equilibrium reaction modelsfor predicting the response of hydrate-bearing systems to externalstimuli, such as changes in pressure and temperature. Specifically, we(1) analyze and compare the responses simulated using both reactionmodels for natural gas production from hydrates in various settings andfor the case of depressurization in a hydrate-bearing core duringextraction; and (2) examine the sensitivity to factors such as initialhydrate saturation, hydrate reaction surface area, and numericaldiscretization. We find that for large-scale systems undergoing thermalstimulation and depressurization, the calculated responses for bothreaction models are remarkably similar, though some differences areobserved at early times. However, for modeling short-term processes, suchas the rapid recovery of a hydrate-bearing core, kinetic limitations canbe important, and neglecting them may lead to significantunder-prediction of recoverable hydrate. The use of the equilibriumreaction model often appears to be justified and preferred for simulatingthe behavior of gas hydrates, given that the computational demands forthe kinetic reaction model far exceed those for the equilibrium reactionmodel.

  5. The effect of BaCO3 on the hydration of OPC and composite cements

    E-Print Network [OSTI]

    Sheffield, University of

    The effect of BaCO3 on the hydration of OPC and composite cements Claire A. Utton* and Neil B of ordinary Portland cement (OPC) and up to 90% blast furnace slag (BFS), are used to encapsulate Intermediate. The effect of BaCO3 on the hydration properties of composite cements is being studied. This paper reports

  6. Experimental study on the formation and dissociation conditions of methane hydrates in porous media

    E-Print Network [OSTI]

    Jung, Woodong

    2002-01-01T23:59:59.000Z

    hydrates formed by methane gas and pure water in porous media. Methane gas hydrates were formed in a cell packed with 0.177-mm (0.007 in) diameter single sand (U.S. Sieve Series Designation Mesh No. 80) and 0.420-mm (0.017 in) diameter single sand (U...

  7. Prediction of gas-hydrate formation conditions in production and surface facilities

    E-Print Network [OSTI]

    Ameripour, Sharareh

    2006-10-30T23:59:59.000Z

    Gas hydrates are a well-known problem in the oil and gas industry and cost millions of dollars in production and transmission pipelines. To prevent this problem, it is important to predict the temperature and pressure under which gas hydrates...

  8. Study of Marine Gas Hydrate on the Northern Cascadia Margin: Constraints from Logging and

    E-Print Network [OSTI]

    Study of Marine Gas Hydrate on the Northern Cascadia Margin: Constraints from Logging and Seismic and gas explaining the high hydrate concentrations at shallow depths of less than 100 meters below of the degree of Master of Science © Xuan Wang 2009 #12; i ABSTRACT This thesis presents estimates of gas

  9. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    E-Print Network [OSTI]

    Seol, Yongkoo

    2010-01-01T23:59:59.000Z

    water saturation and residual water saturation) would bepath blockages caused by residual water or hydrate formed at

  10. Thermal Properties of Methane Hydrate by Experiment and Modeling and Impacts on Technology

    SciTech Connect (OSTI)

    Warzinski, R.P.; Gamwo, I.K.; Rosenbaum, E.M.; Jiang, Hao; Jordan, K.D.; English, N.J. (Univ. College Dublin, IRELAND); Shaw, D.W. (Geneva College, Beaver Falls, PA)

    2008-07-01T23:59:59.000Z

    Thermal properties of pure methane hydrate, under conditions similar to naturally occurring hydrate-bearing sediments being considered for potential production, have been determined both by a new experimental technique and by advanced molecular dynamics simulation (MDS). A novel single-sided, Transient Plane Source (TPS) technique has been developed and used to measure thermal conductivity and thermal diffusivity values of low-porosity methane hydrate formed in the laboratory. The experimental thermal conductivity data are closely matched by results from an equilibrium MDS method using in-plane polarization of the water molecules. MDS was also performed using a non-equilibrium model with a fully polarizable force field for water. The calculated thermal conductivity values from this latter approach were similar to the experimental data. The impact of thermal conductivity on gas production from a hydrate-bearing reservoir was also evaluated using the Tough+/Hydrate reservoir simulator.

  11. Laboratory measurements on core-scale sediment/hydrate samples topredice reservoir behavior

    SciTech Connect (OSTI)

    Kneafsey, Timothy J.; Seol, Yongkoo; Moridis, George J.; Tomutsa,Liviu; Freifeld, Barry M.

    2005-11-02T23:59:59.000Z

    Measurements on hydrate-bearing laboratory and field samplesare necessary in order to provide realistic bounds on parameters used innumerically modeling the production of natural gas from hydrate-bearingreservoirs. The needed parameters include thermal conductivity,permeability, relative permeability-saturation(s) relationships, andcapillary pressure-saturation(s) relationships. We have developed atechnique to make hydrate-bearing samples ranging in scale from coreplug-size to core-size in the laboratory to facilitate making thesemeasurements. In addition to pressure and temperature measurements, weuse x-ray computed tomography scanning to provide high-resolution dataproviding insights on processes occurring in our samples. Several methodsare available to make gas hydrates in the laboratory, and we expect thatthe method used to make the hydrate will impact the behavior of thehydrate sample, and the parameters measured.

  12. Application of fiber optic temperature and strain sensing technology to gas hydrates

    SciTech Connect (OSTI)

    Ulrich, Shannon M [ORNL; Madden, Megan Elwood [ORNL; Rawn, Claudia J [ORNL; Szymcek, Phillip [ORNL; Phelps, Tommy Joe [ORNL

    2008-01-01T23:59:59.000Z

    Gas hydrates may have a significant influence on global carbon cycles due to their large carbon storage capacity in the form of greenhouse gases and their sensitivity to small perturbations in local conditions. Characterizing existing gas hydrate and the formation of new hydrate within sediment systems and their response to small changes in temperature and pressure is imperative to understanding how this dynamic system functions. Fiber optic sensing technology offers a way to measure precisely temperature and strain in harsh environments such as the seafloor. Recent large-scale experiments using Oak Ridge National Laboratory's Seafloor Process Simulator were designed to evaluate the potential of fiber optic sensors to study the formation and dissociation of gas hydrates in 4-D within natural sediments. Results indicate that the fiber optic sensors are so sensitive to experimental perturbations (e.g. refrigeration cycles) that small changes due to hydrate formation or dissociation can be overshadowed.

  13. Recent Advances in Mapping Deep Permafrost and Gas Hydrate Occurrences Using Industry Seismic Data, Richards Island Area, Northwest Territories, Canada

    E-Print Network [OSTI]

    Ramachandran, Kumar

    101 Recent Advances in Mapping Deep Permafrost and Gas Hydrate Occurrences Using Industry Seismic the extent of gas hydrate occurrences beneath it. Seismic amplitude anomalies associated with lakes, primarily related to thermal variations within the permafrost. Keywords: gas hydrates; Mallik; Richards

  14. Frontiers + Innovation 2009 CSPG CSEG CWLS Convention 603 Recent Advances in Mapping Deep Permafrost and Gas Hydrate

    E-Print Network [OSTI]

    Ramachandran, Kumar

    Permafrost and Gas Hydrate Occurrences using Industry Seismic Data, Richards Island Area, Northwest in permafrost and to determine the extent of gas hydrate occurrences. Seismic amplitude anomalies associated that sediments with high gas hydrate saturation near the Mallik well site extend over an area of 0.25 km2

  15. Atmospheric composition, radiative forcing, and climate change as a consequence of a massive methane release from gas hydrates

    E-Print Network [OSTI]

    methane release from gas hydrates Gavin A. Schmidt and Drew T. Shindell National Aeronautics and Space of methane gas (CH4) from hydrate deposits on the continental slope. We investigate whether reported PETM, and climate change as a consequence of a massive methane release from gas hydrates, Paleoceanography, 18

  16. Modelling of Gas Clathrate Hydrate Equilibria using the Electrolyte Non-Random Two-Liquid (eNRTL) Model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Modelling of Gas Clathrate Hydrate Equilibria using the Electrolyte Non-Random Two-Liquid (e + salt2 + gas} systems (salt = NaCl, KCl, CaCl2; gas = CH4, CO2) comprising a gas clathrate hydrate phase-electrolyte aqueous systems involving gas hydrate phases. In the H-Lw-G calculations, fugacities in the gas phase were

  17. Molecular mechanism of the hydration of Candida antarctica1 lipase B in gas phase: water adsorption isotherms and molecular2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Molecular mechanism of the hydration of Candida antarctica1 lipase B in gas phase: water and selectivity of enzymes in organic solvents or33 in gas phase. The molecular mechanism of the hydration - 2919" DOI : 10.1002/cbic.200900544 #12;2 ABSTRACT32 Hydration is a major determinant of activity

  18. A-priori calculation of the refractive index of some simple gas hydrates of structures I and II

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A-priori calculation of the refractive index of some simple gas hydrates of structures I and II O are given to calculate the absolute or relative refractive index of any gas hydrate, provided the host gas scattering 1. Introduction Literature is abundant on gas hydrates, which give rise to a growing attention

  19. Z .Earth and Planetary Science Letters 139 1996 509519 Rock-magnetic signature of gas hydrates in accretionary prism

    E-Print Network [OSTI]

    Housen, Bernie

    Z .Earth and Planetary Science Letters 139 1996 509­519 Rock-magnetic signature of gas hydrates with the presence of gas hydrates. Two indices Z Ä 4 Ä 4. Z Ä 4 .combining coercivity, remanence, and susceptibility that a `fossil gas hydrate zone' extended downwards to about 295 mbsf during the last glacial. The observed

  20. Liquid-state polaron theory of the hydrated electron revisited

    E-Print Network [OSTI]

    James P. Donley; David R. Heine; Caleb A. Tormey; David T. Wu

    2014-12-25T23:59:59.000Z

    The quantum path integral/classical liquid-state theory of Chandler and co-workers, created to describe an excess electron in solvent, is re-examined for the hydrated electron. The portion that models electron-water density correlations is replaced by two equations: the range optimized random phase approximation (RO-RPA), and the DRL approximation to the "two-chain" equation, both shown previously to describe accurately the static structure and thermodynamics of strongly charged polyelectrolyte solutions. The static equilibrium properties of the hydrated electron are analyzed using five different electron-water pseudopotentials. The theory is then compared with data from mixed quantum/classical Monte Carlo and molecular dynamics simulations using these same pseudopotentials. It is found that the predictions of the RO-RPA and DRL-based polaron theories are similar and improve upon previous theory, with values for almost all properties analyzed in reasonable quantitative agreement with the available simulation data. Also, it is found using the Larsen, Glover and Schwartz pseudopotential that the theories give values for the solvation free energy that are at least three times larger than that from experiment.

  1. The thermodynamic properties of hydrated -Al2O3 nanoparticles

    SciTech Connect (OSTI)

    Spencer, Elinor [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Huang, Baiyu [Brigham Young University, Provo] [Brigham Young University, Provo; Parker, Stewart F. [ISIS Facility, Rutherford Appleton Laboratory (ISIS)] [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Kolesnikov, Alexander I [ORNL] [ORNL; Ross, Dr. Nancy [Virginia Polytechnic Institute and State University] [Virginia Polytechnic Institute and State University; Woodfield, Brian [Brigham Young University, Provo] [Brigham Young University, Provo

    2013-01-01T23:59:59.000Z

    In this paper we report a combined calorimetric and inelastic neutron scattering (INS) study of hydrated -Al2O3 ( -alumina) nanoparticles. These complementary techniques have enabled a comprehensive evaluation of the thermodynamic properties of this technological and industrially important metal oxide to be achieved. The isobaric heat capacity (Cp) data presented herein provide further critical insights into the much-debated chemical composition of -alumina nanoparticles. Furthermore, the isochoric heat capacity (Cv) of the surface water, which is so essential to the stability of all metal-oxides at the nanoscale, has been extracted from the high-resolution INS data and differs significantly from that of ice Ih due to the dominating influence of strong surface-water interactions. This study also encompassed the analysis of four -alumina samples with differing pore diameters [4.5 (1), 13.8 (2), 17.9 (3), and 27.2 nm (4)], and the results obtained allow us to unambiguously conclude that the water content and pore size have no influence on the thermodynamic behaviour of hydrated -alumina nanoparticles.

  2. Hydration of non-polar anti-parallel ?-sheets

    SciTech Connect (OSTI)

    Urbic, Tomaz [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ašker?eva 5, SI-1000 Ljubljana (Slovenia)] [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ašker?eva 5, SI-1000 Ljubljana (Slovenia); Dias, Cristiano L., E-mail: cld@njit.edu [Physics Department, New Jersey Institute of Technology, Newark, New Jersey 07102-1982 (United States)

    2014-04-28T23:59:59.000Z

    In this work we focus on anti-parallel ?-sheets to study hydration of side chains and polar groups of the backbone using all-atom molecular dynamics simulations. We show that: (i) water distribution around the backbone does not depend significantly on amino acid sequence, (ii) more water molecules are found around oxygen than nitrogen atoms of the backbone, and (iii) water molecules around nitrogen are highly localized in the planed formed by peptide backbones. To study hydration around side chains we note that anti-parallel ?-sheets exhibit two types of cross-strand pairing: Hydrogen-Bond (HB) and Non-Hydrogen-Bond (NHB) pairing. We show that distributions of water around alanine, leucine, and valine side chains are very different at HB compared to NHB faces. For alanine pairs, the space between side chains has a higher concentration of water if residues are located in the NHB face of the ?-sheet as opposed to the HB face. For leucine residues, the HB face is found to be dry while the space between side chains at the NHB face alternates between being occupied and non-occupied by water. Surprisingly, for valine residues the NHB face is dry, whereas the HB face is occupied by water. We postulate that these differences in water distribution are related to context dependent propensities observed for ?-sheets.

  3. Hydration studies of calcium sulfoaluminate cements blended with fly ash

    SciTech Connect (OSTI)

    García-Maté, M.; De la Torre, A.G. [Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga (Spain)] [Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga (Spain); León-Reina, L. [Servicios Centrales de Apoyo a la Investigación, Universidad de Málaga, 29071 Málaga (Spain)] [Servicios Centrales de Apoyo a la Investigación, Universidad de Málaga, 29071 Málaga (Spain); Aranda, M.A.G. [Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga (Spain) [Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga (Spain); CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); Santacruz, I., E-mail: isantacruz@uma.es [Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga (Spain)

    2013-12-15T23:59:59.000Z

    The main objective of this work is to study the hydration and properties of calcium sulfoaluminate cement pastes blended with fly ash (FA) and the corresponding mortars at different hydration ages. Laboratory X-ray powder diffraction, rheological studies, thermal analysis, porosimetry and compressive strength measurements were performed. The analysis of the diffraction data by Rietveld method allowed quantifying crystalline phases and overall amorphous contents. The studied parameters were: i) FA content, 0, 15 and 30 wt.%; and ii) water addition, water-to-CSA mass ratio (w/CSA = 0.50 and 0.65), and water-to-binder mass ratio (w/b = 0.50). Finally, compressive strengths after 6 months of 0 and 15 wt.% FA [w/CSA = 0.50] mortars were similar: 73 ± 2 and 72 ± 3 MPa, respectively. This is justified by the filler effect of the FA as no strong evidences of reactivity of FA with CSA were observed. These results support the partial substitution of CSA cements with FA with the economic and environmental benefits.

  4. Depth dependent dynamics in the hydration shell of a protein

    E-Print Network [OSTI]

    J. Servantie; C. Atilgan; A. R. Atilgan

    2010-07-31T23:59:59.000Z

    We study the dynamics of hydration water/protein association in folded proteins, using lysozyme and myoglobin as examples. Extensive molecular dynamics simulations are performed to identify underlying mechanisms of the dynamical transition that corresponds to the onset of amplified atomic fluctuations in proteins. The number of water molecules within a cutoff distance of each residue scales linearly with protein depth index and is not affected by the local dynamics of the backbone. Keeping track of the water molecules within the cutoff sphere, we observe an effective residence time, scaling inversely with depth index at physiological temperatures while the diffusive escape is highly reduced below the transition. A depth independent orientational memory loss is obtained for the average dipole vector of the water molecules within the sphere when the protein is functional. While below the transition temperature, the solvent is in a glassy state, acting as a solid crust around the protein, inhibiting any large scale conformational fluctuations. At the transition, most of the hydration shell unfreezes and water molecules collectively make the protein more flexible.

  5. Uptake of chloride and carbonate ions by calcium monosulfoaluminate hydrate

    SciTech Connect (OSTI)

    Mesbah, Adel [Commissariat a l'Energie Atomique et aux Energies Alternatives, CEA DEN/DTCD/SPDE, F-30207 Bagnols sur Ceze (France); Clermont Universite, ENSCCF, Laboratoire des Materiaux Inorganiques, BP 10448, F-63000 Clermont-Ferrand (France); Cau-dit-Coumes, Celine, E-mail: celine.cau-dit-coumes@cea.fr [Commissariat a l'Energie Atomique et aux Energies Alternatives, CEA DEN/DTCD/SPDE, F-30207 Bagnols sur Ceze (France); Renaudin, Guillaume [Clermont Universite, ENSCCF, Laboratoire des Materiaux Inorganiques, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6002, F-63177 Aubiere (France); Frizon, Fabien [Commissariat a l'Energie Atomique et aux Energies Alternatives, CEA DEN/DTCD/SPDE, F-30207 Bagnols sur Ceze (France); Leroux, Fabrice [Clermont Universite, Universite Blaise Pascal, Laboratoire des Materiaux Inorganiques, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6002, F-63177 Aubiere (France)

    2012-08-15T23:59:59.000Z

    Decommissioning of old nuclear reactors may produce waste streams containing chlorides and carbonates, including radioactive {sup 36}Cl{sup -} and {sup 14}CO{sub 3}{sup 2-}. Their insolubilization by calcium monosulfoaluminate hydrate was investigated. Carbonates were readily depleted from the solution, giving at thermodynamic equilibrium monocarboaluminate, monocarboaluminate + calcite, or calcite only, depending on the initial ratio between the anion and calcium monosulfoaluminate hydrate. Chloride ions reacted more slowly and were precipitated as Kuzel's salt, Kuzel's and Friedel's salts, or Friedel's salt only. Rietveld refinement of X-Ray powder diffraction patterns was successfully used to quantify the phase distributions, which were compared to thermodynamic calculations. Moreover, analysing the lattice parameters of Kuzel's salt as a function of its chloride content showed the occurrence of a restricted solid solution towards the sulfate side with general formula 3CaO{center_dot}Al{sub 2}O{sub 3}{center_dot}xCaCl{sub 2}{center_dot}(1 - x)CaSO{sub 4}{center_dot}(12 - 2x){center_dot}H{sub 2}O (0.36 {<=} x {<=} 0.50).

  6. Ab Initio Thermodynamic Model for Magnesium Carbonates and Hydrates

    SciTech Connect (OSTI)

    Chaka, Anne M.; Felmy, Andrew R.

    2014-03-28T23:59:59.000Z

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogs of Ca-based hydrated carbonates monohydrocalcite and ikaite which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  7. Application of Crunch-Flow Routines to Constrain Present and Past Carbon Fluxes at Gas-Hydrate Bearing Sites

    SciTech Connect (OSTI)

    Torres, Marta

    2014-01-31T23:59:59.000Z

    In November 2012, Oregon State University initiated the project entitled: Application of Crunch-Flow routines to constrain present and past carbon fluxes at gas-hydrate bearing sites. Within this project we developed Crunch-Flow based modeling modules that include important biogeochemical processes that need to be considered in gas hydrate environments. Our modules were applied to quantify carbon cycling in present and past systems, using data collected during several DOE-supported drilling expeditions, which include the Cascadia margin in US, Ulleung Basin in South Korea, and several sites drilled offshore India on the Bay of Bengal and Andaman Sea. Specifically, we completed modeling efforts that: 1) Reproduce the compositional and isotopic profiles observed at the eight drilled sites in the Ulleung Basin that constrain and contrast the carbon cycling pathways at chimney (high methane flux) and non-chimney sites (low methane, advective systems); 2) Simulate the Ba record in the sediments to quantify the past dynamics of methane flux in the southern Hydrate Ridge, Cascadia margin; and 3) Provide quantitative estimates of the thickness of individual mass transport deposits (MTDs), time elapsed after the MTD event, rate of sulfate reduction in the MTD, and time required to reach a new steady state at several sites drilled in the Krishna-Godavari (K-G) Basin off India. In addition we developed a hybrid model scheme by coupling a home-made MATLAB code with CrunchFlow to address the methane transport and chloride enrichment at the Ulleung Basins chimney sites, and contributed the modeling component to a study focusing on pore-scale controls on gas hydrate distribution in sediments from the Andaman Sea. These efforts resulted in two manuscripts currently under review, and contributed the modeling component of another pare, also under review. Lessons learned from these efforts are the basis of a mini-workshop to be held at Oregon State University (Feb 2014) to instruct graduate students (OSU and UW) as well as DOE staff from the NETL lab in Albany on the use of Crunch Flow for geochemical applications.

  8. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    SciTech Connect (OSTI)

    Boswell, R.D.; Shelander, D.; Lee, M.; Latham, T.; Collett, T.; Guerin, G.; Moridis, G.; Reagan, M.; Goldberg, D.

    2009-07-15T23:59:59.000Z

    A unique set of high-quality downhole shallow subsurface well log data combined with industry standard 3D seismic data from the Alaminos Canyon area has enabled the first detailed description of a concentrated gas hydrate accumulation within sand in the Gulf of Mexico. The gas hydrate occurs within very fine grained, immature volcaniclastic sands of the Oligocene Frio sand. Analysis of well data acquired from the Alaminos Canyon Block 818 No.1 ('Tigershark') well shows a total gas hydrate occurrence 13 m thick, with inferred gas hydrate saturation as high as 80% of sediment pore space. Average porosity in the reservoir is estimated from log data at approximately 42%. Permeability in the absence of gas hydrates, as revealed from the analysis of core samples retrieved from the well, ranges from 600 to 1500 millidarcies. The 3-D seismic data reveals a strong reflector consistent with significant increase in acoustic velocities that correlates with the top of the gas-hydrate-bearing sand. This reflector extends across an area of approximately 0.8 km{sup 2} and delineates the minimal probable extent of the gas hydrate accumulation. The base of the inferred gas-hydrate zone also correlates well with a very strong seismic reflector that indicates transition into units of significantly reduced acoustic velocity. Seismic inversion analyses indicate uniformly high gas-hydrate saturations throughout the region where the Frio sand exists within the gas hydrate stability zone. Numerical modeling of the potential production of natural gas from the interpreted accumulation indicates serious challenges for depressurization-based production in settings with strong potential pressure support from extensive underlying aquifers.

  9. Site Selection for DOE/JIP Gas Hydrate Drilling in the Northern Gulf of Mexico

    SciTech Connect (OSTI)

    Hutchinson, D.R. (USGS); Shelander, D. (Schlumberger, Houston, TX); Dai, J. (Schlumberger, Hoston, TX); McConnell, D. (AOA Geophysics, Inc., Houston, TX); Shedd, W. (Minerals Management Service); Frye, M. (Minerals Management Service); Ruppel, C. (USGS); Boswell, R.; Jones, E. (Chevron Energy Technology Corp., Houston, TX); Collett, T.S. (USGS); Rose, K.; Dugan, B. (Rice Univ., Houston, TX); Wood, W. (U.S. Naval Research Laboratory); Latham, T. (Chevron Energy Technology Corp., Houston, TX)

    2008-07-01T23:59:59.000Z

    In the late spring of 2008, the Chevron-led Gulf of Mexico Gas Hydrate Joint Industry Project (JIP) expects to conduct an exploratory drilling and logging campaign to better understand gas hydrate-bearing sands in the deepwater Gulf of Mexico. The JIP Site Selection team selected three areas to test alternative geological models and geophysical interpretations supporting the existence of potential high gas hydrate saturations in reservoir-quality sands. The three sites are near existing drill holes which provide geological and geophysical constraints in Alaminos Canyon (AC) lease block 818, Green Canyon (GC) 955, and Walker Ridge (WR) 313. At the AC818 site, gas hydrate is interpreted to occur within the Oligocene Frio volcaniclastic sand at the crest of a fold that is shallow enough to be in the hydrate stability zone. Drilling at GC955 will sample a faulted, buried Pleistocene channel-levee system in an area characterized by seafloor fluid expulsion features, structural closure associated with uplifted salt, and abundant seismic evidence for upward migration of fluids and gas into the sand-rich parts of the sedimentary section. Drilling at WR313 targets ponded sheet sands and associated channel/levee deposits within a minibasin, making this a non-structural play. The potential for gas hydrate occurrence at WR313 is supported by shingled phase reversals consistent with the transition from gas-charged sand to overlying gas-hydrate saturated sand. Drilling locations have been selected at each site to 1) test geological methods and models used to infer the occurrence of gas hydrate in sand reservoirs in different settings in the northern Gulf of Mexico; 2) calibrate geophysical models used to detect gas hydrate sands, map reservoir thicknesses, and estimate the degree of gas hydrate saturation; and 3) delineate potential locations for subsequent JIP drilling and coring operations that will collect samples for comprehensive physical property, geochemical and other analyses.

  10. CX-009330: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Exclusion Determination CX-009330: Categorical Exclusion Determination Gas Hydrate Dynamics on the Alaskan Beaufort Continental Slope: Modeling and Field Characterization CX(s)...

  11. CX-009328: Categorical Exclusion Determination | Department of...

    Broader source: Energy.gov (indexed) [DOE]

    Exclusion Determination CX-009328: Categorical Exclusion Determination Gas Hydrate Dynamics on the Alaskan Beaufort Continental Slope: Modeling and Field Characterization CX(s)...

  12. In situ apparatus for the study of clathrate hydrates relevant to solar system bodies using synchrotron X-ray diffraction and Raman spectroscopy

    E-Print Network [OSTI]

    Day, Sarah J; Evans, Aneurin; Parker, Julia E

    2015-01-01T23:59:59.000Z

    Clathrate hydrates are believed to play a significant role in various solar system environments, e.g. comets, and the surfaces and interiors of icy satellites, however the structural factors governing their formation and dissociation are poorly understood. We demonstrate the use of a high pressure gas cell, combined with variable temperature cooling and time-resolved data collection, to the in situ study of clathrate hydrates under conditions relevant to solar system environments. Clathrates formed and processed within the cell are monitored in situ using synchrotron X-ray powder diffraction and Raman spectroscopy. X-ray diffraction allows the formation of clathrate hydrates to be observed as CO2 gas is applied to ice formed within the cell. Complete conversion is obtained by annealing at temperatures just below the ice melting point. A subsequent rise in the quantity of clathrate is observed as the cell is thermally cycled. Four regions between 100-5000cm-1 are present in the Raman spectra that carry feature...

  13. Scientific Objectives of the Gulf of Mexico Gas Hydrate JIP Leg II Drilling

    SciTech Connect (OSTI)

    Jones, E. (Chevron); Latham, T. (Chevron); McConnell, D. (AOA Geophysics); Frye, M. (Minerals Management Service); Hunt, J. (Minerals Management Service); Shedd, W. (Minerals Management Service); Shelander, D. (Schlumberger); Boswell, R.M. (NETL); Rose, K.K. (NETL); Ruppel, C. (USGS); Hutchinson, D. (USGS); Collett, T. (USGS); Dugan, B. (Rice University); Wood, W. (Naval Research Laboratory)

    2008-05-01T23:59:59.000Z

    The Gulf of Mexico Methane Hydrate Joint Industry Project (JIP) has been performing research on marine gas hydrates since 2001 and is sponsored by both the JIP members and the U.S. Department of Energy. In 2005, the JIP drilled the Atwater Valley and Keathley Canyon exploration blocks in the Gulf of Mexico to acquire downhole logs and recover cores in silt- and clay-dominated sediments interpreted to contain gas hydrate based on analysis of existing 3-D seismic data prior to drilling. The new 2007-2009 phase of logging and coring, which is described in this paper, will concentrate on gas hydrate-bearing sands in the Alaminos Canyon, Green Canyon, and Walker Ridge protraction areas. Locations were selected to target higher permeability, coarser-grained lithologies (e.g., sands) that have the potential for hosting high saturations of gas hydrate and to assist the U.S. Minerals Management Service with its assessment of gas hydrate resources in the Gulf of Mexico. This paper discusses the scientific objectives for drilling during the upcoming campaign and presents the results from analyzing existing seismic and well log data as part of the site selection process. Alaminos Canyon 818 has the most complete data set of the selected blocks, with both seismic data and comprehensive downhole log data consistent with the occurrence of gas hydrate-bearing sands. Preliminary analyses suggest that the Frio sandstone just above the base of the gas hydrate stability zone may have up to 80% of the available sediment pore space occupied by gas hydrate. The proposed sites in the Green Canyon and Walker Ridge areas are also interpreted to have gas hydrate-bearing sands near the base of the gas hydrate stability zone, but the choice of specific drill sites is not yet complete. The Green Canyon site coincides with a 4-way closure within a Pleistocene sand unit in an area of strong gas flux just south of the Sigsbee Escarpment. The Walker Ridge site is characterized by a sand-prone sedimentary section that rises stratigraphically across the base of the gas hydrate stability zone and that has seismic indicators of gas hydrate. Copyright 2008, Offshore Technology Conference

  14. Multi-property characterization chamber for geophysical-hydrological investigations of hydrate bearing sediments

    SciTech Connect (OSTI)

    Seol, Yongkoo, E-mail: Yongkoo.Seol@netl.doe.gov; Choi, Jeong-Hoon; Dai, Sheng [National Energy Technology Laboratory, U.S. Department of Energy, Morgantown, West Virginia 26507 (United States)

    2014-08-01T23:59:59.000Z

    With the increase in the interest of producing natural gas from methane hydrates as well as potential risks of massive hydrate dissociation in the context of global warming, studies have recently shifted from pure hydrate crystals to hydrates in sediments. Such a research focus shift requires a series of innovative laboratory devices that are capable of investigating various properties of hydrate-bearing sediments (HBS). This study introduces a newly developed high pressure testing chamber, i.e., multi-property characterization chamber (MPCC), that allows simultaneous investigation of a series of fundamental properties of HBS, including small-strain stiffness (i.e., P- and S-waves), shear strength, large-strain deformation, stress-volume responses, and permeability. The peripheral coolant circulation system of the MPCC permits stable and accurate temperature control, while the core holder body, made of aluminum, enables X-ray computer tomography scanning to be easily employed for structural and morphological characterization of specimens. Samples of hydrate-bearing sediments are held within a rubber sleeve inside the chamber. The thick sleeve is more durable and versatile than thin membranes while also being much softer than oedometer-type chambers that are incapable of enabling flow tests. Bias introduced by the rubber sleeve during large deformation tests are also calibrated both theoretically and experimentally. This system provides insight into full characterization of hydrate-bearing sediments in the laboratory, as well as pressure core technology in the field.

  15. Sensitivity Analysis of Gas Production from Class 2 and Class 3 Hydrate Deposits

    SciTech Connect (OSTI)

    Reagan, Matthew; Moridis, George; Zhang, Keni

    2008-05-01T23:59:59.000Z

    Gas hydrates are solid crystalline compounds in which gas molecules are lodged within the lattices of an ice-like crystalline solid. The vast quantities of hydrocarbon gases trapped in hydrate formations in the permafrost and in deep ocean sediments may constitute a new and promising energy source. Class 2 hydrate deposits are characterized by a Hydrate-Bearing Layer (HBL) that is underlain by a saturated zone of mobile water. Class 3 hydrate deposits are characterized by an isolated Hydrate-Bearing Layer (HBL) that is not in contact with any hydrate-free zone of mobile fluids. Both classes of deposits have been shown to be good candidates for exploitation in earlier studies of gas production via vertical well designs - in this study we extend the analysis to include systems with varying porosity, anisotropy, well spacing, and the presence of permeable boundaries. For Class 2 deposits, the results show that production rate and efficiency depend strongly on formation porosity, have a mild dependence on formation anisotropy, and that tighter well spacing produces gas at higher rates over shorter time periods. For Class 3 deposits, production rates and efficiency also depend significantly on formation porosity, are impacted negatively by anisotropy, and production rates may be larger, over longer times, for well configurations that use a greater well spacing. Finally, we performed preliminary calculations to assess a worst-case scenario for permeable system boundaries, and found that the efficiency of depressurization-based production strategies are compromised by migration of fluids from outside the system.

  16. Physical property changes in hydrate-bearingsediment due to depressurization and subsequent repressurization

    SciTech Connect (OSTI)

    Kneafsey, Timothy; Waite, W.F.; Kneafsey, T.J.; Winters, W.J.; Mason, D.H.

    2008-06-01T23:59:59.000Z

    Physical property measurements of sediment cores containing natural gas hydrate are typically performed on material exposed at least briefly to non-in situ conditions during recovery. To examine effects of a brief excursion from the gas-hydrate stability field, as can occur when pressure cores are transferred to pressurized storage vessels, we measured physical properties on laboratory-formed sand packs containing methane hydrate and methane pore gas. After depressurizing samples to atmospheric pressure, we repressurized them into the methane-hydrate stability field and remeasured their physical properties. Thermal conductivity, shear strength, acoustic compressional and shear wave amplitudes and speeds are compared between the original and depressurized/repressurized samples. X-ray computed tomography (CT) images track how the gas-hydrate distribution changes in the hydrate-cemented sands due to the depressurization/repressurization process. Because depressurization-induced property changes can be substantial and are not easily predicted, particularly in water-saturated, hydrate-bearing sediment, maintaining pressure and temperature conditions throughout the core recovery and measurement process is critical for using laboratory measurements to estimate in situ properties.

  17. Evaluation of the gas production economics of the gas hydrate cyclic thermal injection model

    SciTech Connect (OSTI)

    Kuuskraa, V.A.; Hammersheimb, E.; Sawyer, W.

    1985-05-01T23:59:59.000Z

    The objective of the work performed under this directive is to assess whether gas hydrates could potentially be technically and economically recoverable. The technical potential and economics of recovering gas from a representative hydrate reservoir will be established using the cyclic thermal injection model, HYDMOD, appropriately modified for this effort, integrated with economics model for gas production on the North Slope of Alaska, and in the deep offshore Atlantic. The results from this effort are presented in this document. In Section 1, the engineering cost and financial analysis model used in performing the economic analysis of gas production from hydrates -- the Hydrates Gas Economics Model (HGEM) -- is described. Section 2 contains a users guide for HGEM. In Section 3, a preliminary economic assessment of the gas production economics of the gas hydrate cyclic thermal injection model is presented. Section 4 contains a summary critique of existing hydrate gas recovery models. Finally, Section 5 summarizes the model modification made to HYDMOD, the cyclic thermal injection model for hydrate gas recovery, in order to perform this analysis.

  18. Contribution of oceanic gas hydrate dissociation to the formation of Arctic Ocean methane plumes

    SciTech Connect (OSTI)

    Reagan, M.; Moridis, G.; Elliott, S.; Maltrud, M.

    2011-06-01T23:59:59.000Z

    Vast quantities of methane are trapped in oceanic hydrate deposits, and there is concern that a rise in the ocean temperature will induce dissociation of these hydrate accumulations, potentially releasing large amounts of carbon into the atmosphere. Because methane is a powerful greenhouse gas, such a release could have dramatic climatic consequences. The recent discovery of active methane gas venting along the landward limit of the gas hydrate stability zone (GHSZ) on the shallow continental slope (150 m - 400 m) west of Svalbard suggests that this process may already have begun, but the source of the methane has not yet been determined. This study performs 2-D simulations of hydrate dissociation in conditions representative of the Arctic Ocean margin to assess whether such hydrates could contribute to the observed gas release. The results show that shallow, low-saturation hydrate deposits, if subjected to recently observed or future predicted temperature changes at the seafloor, can release quantities of methane at the magnitudes similar to what has been observed, and that the releases will be localized near the landward limit of the GHSZ. Both gradual and rapid warming is simulated, along with a parametric sensitivity analysis, and localized gas release is observed for most of the cases. These results resemble the recently published observations and strongly suggest that hydrate dissociation and methane release as a result of climate change may be a real phenomenon, that it could occur on decadal timescales, and that it already may be occurring.

  19. Spectroscopic Signatures of Halogens in Clathrate Hydrate Cages. 1. Bromine Galina Kerenskaya,* Ilya U. Goldschleger, V. Ara Apkarian, and Kenneth C. Janda

    E-Print Network [OSTI]

    Apkarian, V. Ara

    , the earliest gas clathrate hydrate discovered, was first prepared by Davy in 1811;1 bromine hydrateSpectroscopic Signatures of Halogens in Clathrate Hydrate Cages. 1. Bromine Galina Kerenskaya report the first UV-vis spectroscopic study of bromine molecules confined in clathrate hydrate cages

  20. Late PleistoceneHolocene sedimentation surrounding an active seafloor gas-hydrate and cold-seep field on the Northern Gulf of Mexico Slope

    E-Print Network [OSTI]

    Meyers, Stephen R.

    Late Pleistocene­Holocene sedimentation surrounding an active seafloor gas-hydrate and cold 2010 Communicated by J.T. Wells Keywords: gas hydrate(s) cold or petroleum seep(s) Mississippi Canyon 118 (MC118) National Gas Hydrate Seafloor Observatory Gulf of Mexico Late Pleistocene Holocene

  1. Guest disorder and high pressure behavior of argon hydrates

    SciTech Connect (OSTI)

    Yang, L.; Tulk, C.A.; Klug, D.D.; Chakoumakos, B.C.; Ehm, L.; Molaison, J.J.; Parise, J.B.; Simonson, J.M. (NRCC); (SBU); (ORNL)

    2010-03-29T23:59:59.000Z

    The structure of argon hydrate was studied at ambient pressure and low temperature, and between 1.7 and 4.2 GPa at 295 K. This analysis produced a single Ar guest atom, positionally disordered off-center in the large cages of sII. Above 1.7 GPa Ar clathrate transformed to a mixture of a body-centered orthorhombic filled-ice phase, which can be viewed as a polytype of ice-Ih, and high pressure forms of pure ice. The guest disorder is further substantiated by analysis of the guest to host ratio in this high pressure filled-ice structure. The bulk modulus of Ar filled-ice found to be 11.7 {+-} 0.4 GPa.

  2. Origin of Entropy Convergence in Hydrophobic Hydration and Protein Folding

    SciTech Connect (OSTI)

    Garde, S.; Hummer, G.; Garcia, A.E.; Paulaitis, M.E.; Pratt, L.R. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); [Center for Molecular and Engineering Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States); [Department of Chemical Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    1996-12-01T23:59:59.000Z

    An information theory model of hydrophobic effects is used to construct a molecular explanation why hydrophobic solvation entropies of protein unfolding measured by high sensitivity calorimetry converge to zero at a common convergence temperature. The entropy convergence follows directly from the weak temperature dependence of occupancy fluctuations {l_angle}{delta}{ital n}{sup 2}{r_angle} for molecular-scale volumes in water. The macroscopic expression of the contrasting entropic behavior of water relative to common organic solvents is the {ital relative} temperature insensitivity of the water isothermal compressibility compared to hydrocarbon liquids. The information theory model used provides a quantitative description of small molecule hydration and, in addition, predicts that the value of the entropy at convergence is slightly {ital negative}. Interpretations of entropic contributions to protein folding should account for this result. {copyright} {ital 1996 The American Physical Society.}

  3. Method and apparatus for recovering a gas from a gas hydrate located on the ocean floor

    DOE Patents [OSTI]

    Wyatt, Douglas E. (Aiken, SC)

    2001-01-01T23:59:59.000Z

    A method and apparatus for recovering a gas from a gas hydrate on the ocean floor includes a flexible cover, a plurality of steerable base members secured to the cover, and a steerable mining module. A suitable source for inflating the cover over the gas hydrate deposit is provided. The mining module, positioned on the gas hydrate deposit, is preferably connected to the cover by a control cable. A gas retrieval conduit or hose extends upwardly from the cover to be connected to a support ship on the ocean surface.

  4. Numerical simulation studies of gas production scenarios from hydrate accumulations at the Mallik Site, McKenzie Delta, Canada

    SciTech Connect (OSTI)

    Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Stephen; Weatherill, Brian

    2002-03-22T23:59:59.000Z

    The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. An 1150 m deep gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from several gas-hydrate-bearing zones at the Mallik site. The TOUGH2 general-purpose simulator with the EOSHYDR2 module were used for the analysis. EOSHYDR2 is designed to model the non-isothermal CH{sub 4} (methane) release, phase behavior and flow under conditions typical of methane-hydrate deposits by solving the coupled equations of mass and heat balance, and can describe any combination of gas hydrate dissociation mechanisms. Numerical simulations indicated that significant gas hydrate production at the Mallik site was possible by drawing down the pressure on a thin free-gas zone at the base of the hydrate stability field. Gas hydrate zones with underlying aquifers yielded significant gas production entirely from dissociated gas hydrate, but large amounts of produced water. Lithologically isolated gas-hydrate-bearing reservoirs with no underlying free gas or water zones, and gas-hydrate saturations of at least 50% were also studied. In these cases, it was assumed that thermal stimulation by circulating hot water in the well was the method used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increases with gas-hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the rock and hydrate specific heat and permeability of the formation.

  5. Numerical studies of gas production from several CH4-hydrate zones at the Mallik Site, Mackenzie Delta, Canada

    SciTech Connect (OSTI)

    Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Steven; Weatherill, Brian

    2002-05-08T23:59:59.000Z

    The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. A gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from several gas-hydrate-bearing zones at the Mallik site. The TOUGH2 general-purpose simulator with the EOSHYDR2 module were used for the analysis. EOSHYDR2 is designed to model the non-isothermal CH{sub 4} release, phase behavior and flow under conditions typical of methane-hydrate deposits by solving the coupled equations of mass and heat balance, and can describe any combination of gas hydrate dissociation mechanisms. Numerical simulations indicated that significant gas hydrate production at the Mallik site was possible by drawing down the pressure on a thin free-gas zone at the base of the hydrate stability field. Gas hydrate zones with underlying aquifers yielded significant gas production entirely from dissociated gas hydrate, but large amounts of produced water. Lithologically isolated gas-hydrate-bearing reservoirs with no underlying free gas or water zones, and gas-hydrate saturations of at least 50% were also studied. In these cases, it was assumed that thermal stimulation by circulating hot water in the well was the method used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increases with gas-hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the rock and hydrate specific heat and permeability of the formation.

  6. Substantially self-powered method and apparatus for recovering hydrocarbons from hydrocarbon-containing solid hydrates

    DOE Patents [OSTI]

    Elliott, G.R.B.; Barraclough, B.L.; Vanderborgh, N.E.

    1981-02-19T23:59:59.000Z

    A method and apparatus are provided for producing gaseous hydrocarbons from formations comprising solid hydrocarbon hydrates located under either a body of land or a body of water. The vast natural resources of such hydrocarbon hydrates can thus now be economically mined. Relatively warm brine or water is brought down from an elevation above that of the hydrates through a portion of the apparatus, and passes in contact with the hydrates, thus melting them. The liquid then continues up another portion of the apparatus carrying entrained hydrocarbon vapors in the form of bubbles, which can easily be separated from the liquid. After a short startup procedure, the process and apparatus are substantially self-powered.

  7. Substantially self-powered method and apparatus for recovering hydrocarbons from hydrocarbon-containing solid hydrates

    DOE Patents [OSTI]

    Elliott, Guy R. B. (Los Alamos, NM); Barraclough, Bruce L. (Santa Fe, NM); Vanderborgh, Nicholas E. (Los Alamos, NM)

    1983-01-01T23:59:59.000Z

    A method and apparatus are provided for producing gaseous hydrocarbons from formations comprising solid hydrocarbon hydrates located under either a body of land or a body of water. The vast natural resources of such hydrocarbon hydrates can thus now be economically mined. Relatively warm brine or water is brought down from an elevation above that of the hydrates through a portion of the apparatus and passes in contact with the hydrates, thus melting them. The liquid then continues up another portion of the apparatus, carrying entrained hydrocarbon vapors in the form of bubbles, which can easily be separated from the liquid. After a short startup procedure, the process and apparatus are substantially self-powered.

  8. Apparatus for recovering gaseous hydrocarbons from hydrocarbon-containing solid hydrates

    DOE Patents [OSTI]

    Elliott, Guy R. B. (Los Alamos, NM); Barraclough, Bruce L. (Santa Fe, NM); Vanderborgh, Nicholas E. (Los Alamos, NM)

    1984-01-01T23:59:59.000Z

    A method and apparatus are provided for producing gaseous hydrocarbons from formations comprising solid hydrocarbon hydrates located under either a body of land or a body of water. The vast natural resources of such hydrocarbon hydrates can thus now be economically mined. Relatively warm brine or water is brought down from an elevation above that of the hydrates through a portion of the apparatus and passes in contact with the hydrates, thus melting them. The liquid then continues up another portion of the apparatus, carrying entrained hydrocarbon vapors in the form of bubbles, which can easily be separated from the liquid. After a short startup procedure, the process and apparatus are substantially self-powered.

  9. THE SYSTEM THORIUM NITRATE-WATER-NITRIC ACID AT 25 AND THE HYDRATES...

    Office of Scientific and Technical Information (OSTI)

    SYSTEM THORIUM NITRATE-WATER-NITRIC ACID AT 25 AND THE HYDRATES OF THORIUM NITRATE Re-direct Destination: times redirected to final destination ShortURL Code Published Current...

  10. Gas Hydrate Equilibrium Measurements for Multi-Component Gas Mixtures and Effect of Ionic Liquid Inhibitors 

    E-Print Network [OSTI]

    Othman, Enas Azhar

    2014-04-07T23:59:59.000Z

    Qatar holds the world's third-largest proven reserves of natural gas at 885 trillion cubic feet according to a recent report. Because of its desert climate, gas hydrate formation may seem an unlikely event in Qatar. However, ...

  11. Development of Alaskan gas hydrate resources: Annual report, October 1986--September 1987

    SciTech Connect (OSTI)

    Sharma, G.D.; Kamath, V.A.; Godbole, S.P.; Patil, S.L.; Paranjpe, S.G.; Mutalik, P.N.; Nadem, N.

    1987-10-01T23:59:59.000Z

    Solid ice-like mixtures of natural gas and water in the form of natural gas hydrated have been found immobilized in the rocks beneath the permafrost in Arctic basins and in muds under the deep water along the American continental margins, in the North Sea and several other locations around the world. It is estimated that the arctic areas of the United States may contain as much as 500 trillion SCF of natural gas in the form of gas hydrates (Lewin and Associates, 1983). While the US Arctic gas hydrate resources may have enormous potential and represent long term future source of natural gas, the recovery of this resource from reservoir frozen with gas hydrates has not been commercialized yet. Continuing study and research is essential to develop technologies which will enable a detailed characterization and assessment of this alternative natural gas resource, so that development of cost effective extraction technology.

  12. Detection of Gas Hydrates in Garden Banks and Keathley Canyon from Seismic Data

    E-Print Network [OSTI]

    Murad, Idris

    2011-08-08T23:59:59.000Z

    , where the sub-seafloor is a complex structure of shallow salt diapirs and sheets underlying heavily deformed shallow sediments and surrounding diverse minibasins. Here, we consider the effect these structural factors have on gas hydrate occurrence...

  13. New insights into water bonding during early tricalcium silicate hydration with quasielastic neutron scattering

    SciTech Connect (OSTI)

    Gutberlet, T., E-mail: gutberlet@cbm.bv.tum.de [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany); Hilbig, H.; Beddoe, R.E. [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany)] [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany); Lohstroh, W. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany)] [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany)

    2013-09-15T23:59:59.000Z

    New information on the water bonding during the first 36 h of hydration of tricalcium silicate was obtained using the high neutron flux at the sample position of the time-of-flight spectrometer (TOFTOF), FRM II in Garching, Germany, together with {sup 29}Si NMR and X-ray diffraction measurements. A rapid increase in the amount of constrained water was observed at the beginning of the induction period. This is attributed to the formation of an early C-S-H with a large specific surface area (around 800 m{sup 2}/g). During subsequent hydration, the amount of constrained water, as given by the total surface area of the hydration products, is controlled by (a) the formation of new metastable early C-S-H which increases total surface area and (b) polymerisation processes which reduce total surface area. The relative contribution of these processes varies during hydration.

  14. Fluid dynamics of sinking carbon dioxide hydrate particle releases for direct ocean carbon sequestration

    E-Print Network [OSTI]

    Chow, Aaron C. (Aaron Chunghin), 1978-

    2008-01-01T23:59:59.000Z

    One strategy to remove anthropogenic CO? from the atmosphere to mitigate climate change is by direct ocean injection. Liquid CO? can react with seawater to form solid partially reacted CO? hydrate composite particles (pure ...

  15. Observation of Fragile-to-Strong Dynamic Crossover in Protein Hydration Water

    E-Print Network [OSTI]

    Sow-Hsin Chen; Li Liu; Emiliano Fratini; Piero Baglioni; Antonio Faraone; Eugene Mamontov

    2006-05-11T23:59:59.000Z

    At low temperatures proteins exist in a glassy state, a state which has no conformational flexibility and shows no biological functions. In a hydrated protein, at and above 220 K, this flexibility is restored and the protein is able to sample more conformational sub-states, thus becomes biologically functional. This 'dynamical' transition of protein is believed to be triggered by its strong coupling with the hydration water, which also shows a similar dynamic transition. Here we demonstrate experimentally that this sudden switch in dynamic behavior of the hydration water on lysozyme occurs precisely at 220 K and can be described as a Fragile-to-Strong dynamic crossover (FSC). At FSC, the structure of hydration water makes a transition from predominantly high-density (more fluid state) to low-density (less fluid state) forms derived from existence of the second critical point at an elevated pressure.

  16. A sample cell to study hydrate formation with x-ray scattering

    SciTech Connect (OSTI)

    Conrad, Heiko; Lehmkuehler, Felix; Sternemann, Christian; Feroughi, Omid; Tolan, Metin [Fakultaet Physik/DELTA, Technische Universitaet Dortmund, Maria-Goeppert-Mayer-Str. 2, Dortmund D-44221 (Germany); Simonelli, Laura; Huotari, Simo [European Synchrotron Radiation Facility, Boite Postale 220, Grenoble Cedex 9 F-38043 (France)

    2009-02-15T23:59:59.000Z

    We present a new sample cell for measuring nonresonant inelastic x-ray scattering spectra of a tetrahydrofuran (THF)-water liquid mixture and THF hydrate. The hydrate is formed inside the cell after nucleation seeds have been offered by a special magnetic stirring mechanism. Hydrate formation was verified by wide angle x-ray scattering and nonresonant x-ray Raman scattering spectra at the oxygen K-edge. A broad range of scattering angles can be studied with this cell which is necessary for momentum transfer dependent inelastic x-ray scattering. This cell is ideal to examine other liquid hydrate formers or other liquid samples, which have to be mixed in situ during the measurements.

  17. Sodium sulfate heptahydrate: a synchrotron energy-dispersive diffraction study of an elusive metastable hydrated salt 

    E-Print Network [OSTI]

    Hamilton, Andrea; Hall, Christopher

    2008-01-01T23:59:59.000Z

    We describe an unusual application of synchrotron energy-dispersive diffraction with hard X-rays to obtain structural information on metastable sodium sulfate heptahydrate. This hydrate was often mentioned in nineteenth ...

  18. Water Density Fluctuations Relevant to Hydrophobic Hydration are Unaltered by Attractions

    E-Print Network [OSTI]

    Richard C. Remsing; Amish J. Patel

    2015-02-18T23:59:59.000Z

    An understanding of density fluctuations in bulk water has made significant contributions to our understanding of the hydration and interactions of idealized, purely repulsive hydrophobic solutes. To similarly inform the hydration of realistic hydrophobic solutes that have dispersive interactions with water, here we characterize water density fluctuations in the presence of attractive fields that correspond to solute-water attractions. We find that when the attractive field acts only in the solute hydration shell, but not in the solute core, it does not significantly alter water density fluctuations in the solute core region. We further find that for a wide range of solute sizes and attraction strengths, the free energetics of turning on the attractive fields in bulk water are accurately captured by linear response theory. Our results also suggest strategies for more efficiently estimating hydration free energies of realistic solutes in bulk water and at interfaces.

  19. Logarithmic Decay in Single-Particle Relaxation of Hydrated Lysozyme Powder

    E-Print Network [OSTI]

    Baglioni, Piero

    We present the self-dynamics of protein amino acids of hydrated lysozyme powder around the physiological temperature by means of molecular dynamics simulations. The self-intermediate scattering functions of the amino acid ...

  20. Thermodynamic and hydrodynamic constraints on overpressure caused by hydrate dissociation: A pore?scale model

    E-Print Network [OSTI]

    Holtzman, Ran

    It has been suggested that volume expansion caused by hydrate dissociation in sediment pores can result in large overpressure, which in turn may destabilize the sediment and trigger massive submarine landslides. Here, we ...

  1. Kinetics of Methane Hydrate Decomposition Studied via in Situ Low Temperature X-ray Powder Diffraction

    SciTech Connect (OSTI)

    Everett, Susan M [ORNL; Rawn, Claudia J [ORNL; Keffer, David J. [University of Tennessee, Knoxville (UTK); Mull, Derek L [ORNL; Payzant, E Andrew [ORNL; Phelps, Tommy Joe [ORNL

    2013-01-01T23:59:59.000Z

    Gas hydrates are known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice termed self-preservation or anomalous preservation. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Two regions of slowed decomposition for methane hydrate, 180 200 K and 230 260 K, were observed, and the kinetics were studied by in situ low temperature x-ray powder diffraction. The kinetic constants for ice formation from methane hydrate were determined by the Avrami model within each region and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180 200 K was 42 kJ/mol and for 230 260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.

  2. Synthesis, formation mechanism and sensing properties of WO{sub 3} hydrate nanowire netted-spheres

    SciTech Connect (OSTI)

    Yan, Aihua [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)] [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Xie, Changsheng, E-mail: csxie@mail.hust.edu.cn [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China) [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zeng, Dawen [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)] [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Cai, Shuizhou; Hu, Mulin [Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)] [Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-10-15T23:59:59.000Z

    Tungsten oxide hydrate nanowire netted-spheres were successfully synthesized in the glycol solution using a facile solvothermal approach. The nanowires with uniform diameter of 4-6 nm are actually a kind of tungsten oxide hydrate/surfactant hybrid materials. The influence of surfactant, solvent, time and temperature on tailoring morphology was investigated in detail. The possible formation process of WO{sub 3} hydrate nanowire netted-sphere was proposed. Sensing properties of such WO{sub 3} hydrate sensor show that the desirable sensing characteristics towards 100 ppm ammonia gas at 320 {sup o}C were obtained, such as rapid response (18.3 s), high sensitivity, good reproducibility and stability.

  3. Molecular computations for reactions and phase transitions: applications to protein stabilization, hydrates and catalysis

    E-Print Network [OSTI]

    Anderson, Brian J.

    In this work we have made significant contributions in three different areas of interest: therapeutic protein stabilization, thermodynamics of natural gas clathrate-hydrates, and zeolite catalysis. In all three fields, ...

  4. Dynamics of a globular protein and its hydration water studied by neutron scattering and MD simulations

    E-Print Network [OSTI]

    Chen, Sow-Hsin

    2010-01-01T23:59:59.000Z

    This review article describes our neutron scattering experiments made in the past four years for the understanding of the single-particle (hydrogen atom) dynamics of a protein and its hydration water and the strong coupling ...

  5. Polymer electrolyte membranes from fluorinated polyisoprene-block-sulfonated polystyrene: Structural evolution with hydration and heating

    SciTech Connect (OSTI)

    Sodeye, Akinbode [Department of Polymer Science and Engineering, University of Massachusetts; Huang, Tianzi [University of Tennessee, Knoxville (UTK); Gido, Samuel [University of Massachusetts, Amherst; Mays, Jimmy [ORNL

    2011-01-01T23:59:59.000Z

    Small-angle neutron scattering (SANS) and ultra-small-angle X-ray scattering (USAXS) have been used to study the structural changes in fluorinated polyisoprene/sulfonated polystyrene (FISS) diblock copolymers as they evolved from the dry state to the water swollen state. A dilation of the nanometer-scale hydrophilic domains has been observed as hydration increased, with greater dilation occurring in the more highly sulfonated samples or upon hydration at higher temperatures. Furthermore, a decrease in the order in these phase separated structures is observed upon swelling. The glass transition temperatures of the fluorinated blocks have been observed to decrease upon hydration of these materials, and at the highest hydration levels, differential scanning calorimetry (DSC) has shown the presence of tightly bound water. A precipitous drop in the mechanical integrity of the 50% sulfonated materials is also observed upon exceeding the glass transition temperature (Tg), as measured by dynamic mechanical analysis (DMA).

  6. Development of an electrical resistivity cone for the detection of gas hydrates in marine sediments

    E-Print Network [OSTI]

    McClelland, Martha Ann

    1994-01-01T23:59:59.000Z

    Natural gas hydrates are formed when, under certain pressure and temperature conditions, gas molecules become encaged by hydrogenbonded oxygen atoms, forming a solid, ice-like crystalline substance. They have been found all over the world in both...

  7. Product design and development of an aerodynamic hydration system for bicycling and triathlon

    E-Print Network [OSTI]

    Cote, Mark (Mark Brian)

    2007-01-01T23:59:59.000Z

    Proper hydration and aerodynamic performance are both essential needs of a competitive cyclist or triathlete. Several aerodynamic systems have been developed for use on bicycles but few have been designed to be truly ...

  8. Transition state structures for the hydration of 1,3-dichloroacetone

    E-Print Network [OSTI]

    Cutting, Rebecca Ruth

    1985-01-01T23:59:59.000Z

    TRANSITION STATE STRUCTURES FOR THE HYDRATION OF 3, 3-DI CHLOROACETONE A Thesis by REBECCA RUTH CUTTING Submitted to the Graduate College of Texas ASH University in partial fulfillment of the requirements for the degree of HASTER OF SCIENCE... Hay 1985 Hajor Subject; Chemistry TRANSITION STATE STRUCTURES FOR THE HYDRATION OF 1, 3-DICHLOROACETONE A Thesis by REBECCA RUTH CUTTING Approyed as to style and content by; g o n , ogg ( airman of Corsaittee) enn . arding (Member) J, . a...

  9. Hydrates detection by cone penetration testing: cone penetration tests through ice layers

    E-Print Network [OSTI]

    Jeanjean, Philippe Henri

    1991-01-01T23:59:59.000Z

    HYDRATES DETECTION BY CONE PENETRATION TESTING: PART I: CONE PENETRATION TESTS THROUGH ICE LAYERS A Thesis by PHILIPPE HENRI JEANJEAN Submitted to the Office of Graduate Studies of Texas ABcM University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE May 1991 Major Subject: Civil Engineering HYDRATES DETECTION BY CONE PENETRATION TESTING: PART I: CONE PENETRATION TESTS THROUGH ICE LAYERS A Thesis by PHILIPPE HENRI JEANJEAN Approved as to style...

  10. The effect of reservoir heterogeneity on gas production from hydrate accumulations in the permafrost

    SciTech Connect (OSTI)

    Reagan, M. T.; Kowalsky, M B.; Moridis, G. J.; Silpngarmlert, S.

    2010-05-01T23:59:59.000Z

    The quantity of hydrocarbon gases trapped in natural hydrate accumulations is enormous, leading to significant interest in the evaluation of their potential as an energy source. Large volumes of gas can be readily produced at high rates for long times from methane hydrate accumulations in the permafrost by means of depressurization-induced dissociation combined with conventional technologies and horizontal or vertical well configurations. Initial studies on the possibility of natural gas production from permafrost hydrates assumed homogeneity in intrinsic reservoir properties and in the initial condition of the hydrate-bearing layers (either due to the coarseness of the model or due to simplifications in the definition of the system). These results showed great promise for gas recovery from Class 1, 2, and 3 systems in the permafrost. This work examines the consequences of inevitable heterogeneity in intrinsic properties, such as in the porosity of the hydrate-bearing formation, or heterogeneity in the initial state of hydrate saturation. Heterogeneous configurations are generated through multiple methods: (1) through defining heterogeneous layers via existing well-log data, (2) through randomized initialization of reservoir properties and initial conditions, and (3) through the use of geostatistical methods to create heterogeneous fields that extrapolate from the limited data available from cores and well-log data. These extrapolations use available information and established geophysical methods to capture a range of deposit properties and hydrate configurations. The results show that some forms of heterogeneity, such as horizontal stratification, can assist in production of hydrate-derived gas. However, more heterogeneous structures can lead to complex physical behavior within the deposit and near the wellbore that may obstruct the flow of fluids to the well, necessitating revised production strategies. The need for fine discretization is crucial in all cases to capture dynamic behavior during production.

  11. GAS METHANE HYDRATES-RESEARCH STATUS, ANNOTATED BIBLIOGRAPHY, AND ENERGY IMPLICATIONS

    SciTech Connect (OSTI)

    James Sorensen; Jaroslav Solc; Bethany Bolles

    2000-07-01T23:59:59.000Z

    The objective of this task as originally conceived was to compile an assessment of methane hydrate deposits in Alaska from available sources and to make a very preliminary evaluation of the technical and economic feasibility of producing methane from these deposits for remote power generation. Gas hydrates have recently become a target of increased scientific investigation both from the standpoint of their resource potential to the natural gas and oil industries and of their positive and negative implications for the global environment After we performed an extensive literature review and consulted with representatives of the U.S. Geological Survey (USGS), Canadian Geological Survey, and several oil companies, it became evident that, at the current stage of gas hydrate research, the available information on methane hydrates in Alaska does not provide sufficient grounds for reaching conclusions concerning their use for energy production. Hence, the original goals of this task could not be met, and the focus was changed to the compilation and review of published documents to serve as a baseline for possible future research at the Energy & Environmental Research Center (EERC). An extensive annotated bibliography of gas hydrate publications has been completed. The EERC will reassess its future research opportunities on methane hydrates to determine where significant initial contributions could be made within the scope of limited available resources.

  12. Electric Double-Layer Capacitor Based on an Ionic Clathrate Hydrate

    SciTech Connect (OSTI)

    Lee, Wonhee; Kwon, Minchul; Park, Seongmin; Lim, Dongwook Cha, Dr Jong-Ho; Lee, Dr. Huen

    2013-07-01T23:59:59.000Z

    Herein, we suggest a new approach to an electric double-layer capacitor (EDLC) that is based on a proton-conducting ionic clathrate hydrate (ICH). The ice-like structures of clathrate hydrates, which are comprised of host water molecules and guest ions, make them suitable for applications in EDLC electrolytes, owing to their high proton conductivities and thermal stabilities. The carbon materials in the ICH Me{sub 4}NOH[DOT OPERATOR]5?H{sub 2}O show a high specific capacitance, reversible charge–discharge behavior, and a long cycle life. The ionic-hydrate complex provides the following advantages in comparison with conventional aqueous and polymer electrolytes: 1)?The ICH does not cause leakage problems under normal EDLC operating conditions. 2)?The hydrate material can be utilized itself, without requiring any pre-treatments or activation for proton conduction, thus shortening the preparation procedure of the EDLC. 3)?The crystallization of the ICH makes it possible to tailor practical EDLC dimensions because of its fluidity as a liquid hydrate. 4)?The hydrate solid electrolyte exhibits more-favorable electrochemical stability than aqueous and polymer electrolytes. Therefore, ICH materials are expected to find practical applications in versatile energy devices that incorporate electrochemical systems.

  13. Gas Hydrate Characterization in the GoM using Marine EM Methods

    SciTech Connect (OSTI)

    Steven Constable

    2012-03-31T23:59:59.000Z

    In spite of the importance of gas hydrate as a low-carbon fuel, a possible contributor to rapid climate change, and a significant natural hazard, our current understanding about the amount and distribution of submarine gas hydrate is somewhat poor; estimates of total volume vary by at least an order of magnitude, and commercially useful concentrations of hydrate have remained an elusive target. This is largely because conventional geophysical tools have intrinsic limitations in their ability to quantitatively image hydrate. It has long been known from well logs that gas hydrate is resistive compared to the host sediments, and electrical and electromagnetic methods have been proposed and occasionally used to image hydrates. This project seeks to expand our capabilities to use electromagnetic methods to explore for gas hydrate in the marine environment. An important basic science aspect of our work was to quantify the resistivity of pure gas hydrate as a function of temperature at seafloor pressures. We designed, constructed, and tested a highpressure cell in which hydrate could be synthesized and then subjected to electrical conductivity measurements. Impedance spectroscopy at frequencies between 20 Hz and 2 MHz was used to separate the effect of the blocking electrodes from the intrinsic conductivity of the hydrate. We obtained very reproducible results that showed that pure methane hydrate was several times more resistive than the water ice that seeded the synthesis, 20,000 {Ohm}m at 0{degrees}#14;C, and that the activation energy is 30.6 kJ/mol over the temperature range of -15 to 15{degrees}#14;C. Adding silica sand to the hydrate, however, showed that the addition of the extra phase caused the conductivity of the assemblage to increase in a counterintuitive way. The fact that the increased conductivity collapsed after a percolation threshold was reached, and that the addition of glass beads does not produce a similar increase in conductivity, together suggest that while the surface of the gas hydrate grains are not intrinsically conductive, the presence of sand does increase their conductivity. In the field component of this project, we carried out an 18day cruise on the R.V. Roger Revelle in the Gulf of Mexico from 7th-Ã?Â?26th October 2008 to collect controlled-source electromagnetic (CSEM) data over four hydrate prospects; blocks AC 818, WR 313, GC 955, and MC 118. During these surveys we deployed 30 ocean bottom electromagnetic (OBEM) recorders a total of 94 times at four survey areas and towed the Scripps Undersea Electromagnetic Source Instrument (SUESI) a total of 103 hours. SUESI transmission was 200 A on a 50 m dipole antenna at heights of 70-100 m above the seafloor. We also towed a neutrally buoyant 3-axis electric field recorder behind the SUESI antenna at a constant offset of 300 m. The use of a towed receiver that is "flown" above the seafloor allowed us to operate in areas where seafloor infrastructure such as wellheads, pipelines, and installed scientific equipment existed. We reduced the data to apparent resistivity psuedosections. The most compelling results come from the hydrate observatory at MC 118, where a localized resistivity anomaly is clearly identified under the southeast crater in an otherwise uniform 1 {Ohm}m background. The data from MC 118 also show that authigenic carbonate does not necessarily express itself as a confounding resistor, as was feared at the start of this project. While the results from the other prospects are much more complicated, the data are well correlated with known geology, and line to line agreement is good. Although these data are not amenable to 1D inversion as was initially hoped, we expect to use a newly developed 2D CSEM inversion code to continue to get useful information from this rich data set.

  14. In-Situ Sampling and Characterization of Naturally Occurring Marine Methane Hydrate Using the D/V JOIDES Resolution

    SciTech Connect (OSTI)

    Frank Rack; Gerhard Bohrmann; Anne Trehu; Michael Storms; Derryl Schroeder; ODP Leg 204 Shipboard Scientific Party

    2002-09-30T23:59:59.000Z

    The primary accomplishment of the JOI Cooperative Agreement with DOE/NETL in this quarter was the deployment of tools and measurement systems on ODP Leg 204 to study hydrate deposits on Hydrate Ridge, offshore Oregon from July through September, 2002. During Leg 204, we cored and logged 9 sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of hydrates in situ. A 3D seismic survey conducted in 2000 provided images of potential subsurface fluid conduits and indicated the position of the GHSZ throughout the survey region. After coring the first site, we acquired Logging-While-Drilling (LWD) data at all but one site to provide an overview of downhole physical properties. The LWD data confirmed the general position of key seismic stratigraphic horizons and yielded an initial estimate of hydrate concentration through the proxy of in situ electrical resistivity. These records proved to be of great value in planning subsequent coring. The second new hydrate proxy to be tested was infrared thermal imaging of cores on the catwalk as rapidly as possible after retrieval. The thermal images were used to identify hydrate samples and to map estimate the distribution and texture of hydrate within the cores. Geochemical analyses of interstitial waters and of headspace and void gases provide additional information on the distribution and concentration of hydrate within the stability zone, the origin and pathway of fluids into and through the GHSZ, and the rates at which the process of gas hydrate formation is occurring. Bio- and lithostratigraphic description of cores, measurement of physical properties, and in situ pressure core sampling and thermal measurements complement the data set, providing ground-truth tests of inferred physical and sedimentological properties. Among the most interesting preliminary results are: (1) the discovery that gas hydrates are distributed through a broad depth range within the GHSZ and that different physical and chemical proxies for hydrate distribution and concentration give generally consistent results; (2) evidence for the importance of sediment properties for controlling the migration of fluids in the accretionary complex; (3) geochemical indications that the gas hydrate system at Hydrate Ridge contains significant concentrations of higher order hydrocarbons and that fractionation and mixing signals will provide important constraints on gas hydrate dynamics; and (4) the discovery of very high chlorinity values that extend for at least 10 mbsf near the summit, indicating that hydrate formation here must be very rapid.

  15. The Research Path to Determining the Natural Gas Supply Potential of Marine Gas Hydrates

    SciTech Connect (OSTI)

    Boswell, R.M.; Rose, K.K.; Baker, R.C.

    2008-06-01T23:59:59.000Z

    A primary goal of the U.S. National Interagency Gas Hydrates R&D program is to determine the natural gas production potential of marine gas hydrates. In pursuing this goal, four primary areas of effort are being conducted in parallel. First, are wide-ranging basic scientific investigations in both the laboratory and in the field designed to advance the understanding of the nature and behavior of gas hydrate bearing sediments (GHBS). This multi-disciplinary work has wide-ranging direct applications to resource recovery, including assisting the development of exploration and production technologies through better rock physics models for GHBS and also in providing key data for numerical simulations of productivity, reservoir geomechanical response, and other phenomena. In addition, fundamental science efforts are essential to developing a fuller understanding of the role gas hydrates play in the natural environment and the potential environmental implications of gas hydrate production, a critical precursor to commercial extraction. A second area of effort is the confirmation of resource presence and viability via a series of multi-well marine drilling expeditions. The collection of data in the field is essential to further clarifying what proportion of the likely immense in-place marine gas hydrate resource exists in accumulations of sufficient quality to represent potential commercial production prospects. A third research focus area is the integration of geologic, geophysical, and geochemical field data into an effective suite of exploration tools that can support the delineation and characterization commercial gas hydrate prospects prior to drilling. The fourth primary research focus is the development and testing of well-based extraction technologies (including drilling, completion, stimulation and production) that can safely deliver commercial gas production rates from gas hydrate reservoirs in a variety of settings. Initial efforts will take advantage of the relatively favorable economics of conducting production tests in Arctic gas-hydrate bearing sandstones with the intent of translating the knowledge gained to later testing in marine sandstone reservoirs. The full and concurrent pusuit of each of these research topics is essential to the determining the future production potential of naturally-occuring gas hydrates.

  16. Hydration structure of salt solutions from ab initio molecular dynamics

    SciTech Connect (OSTI)

    Bankura, Arindam; Carnevale, Vincenzo; Klein, Michael L. [Institute for Computational Molecular Science and Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122 (United States)

    2013-01-07T23:59:59.000Z

    The solvation structures of Na{sup +}, K{sup +}, and Cl{sup -} ions in aqueous solution have been investigated using density functional theory (DFT) based Car-Parrinello (CP) molecular dynamics (MD) simulations. CPMD trajectories were collected for systems containing three NaCl or KCl ion pairs solvated by 122 water molecules using three different but commonly employed density functionals (BLYP, HCTH, and PBE) with electron correlation treated at the level of the generalized gradient approximation (GGA). The effect of including dispersion forces was analyzed through the use of an empirical correction to the DFT-GGA scheme. Special attention was paid to the hydration characteristics, especially the structural properties of the first solvation shell of the ions, which was investigated through ion-water radial distribution functions, coordination numbers, and angular distribution functions. There are significant differences between the present results obtained from CPMD simulations and those provided by classical MD based on either the CHARMM force field or a polarizable model. Overall, the computed structural properties are in fair agreement with the available experimental results. In particular, the observed coordination numbers 5.0-5.5, 6.0-6.4, and 6.0-6.5 for Na{sup +}, K{sup +}, and Cl{sup -}, respectively, are consistent with X-ray and neutron scattering studies but differ somewhat from some of the many other recent computational studies of these important systems. Possible reasons for the differences are discussed.

  17. Structure Stability of Methane Hydrate at High Pressures

    SciTech Connect (OSTI)

    J Shu; X Chen; I Chou; W Yang; J Hu; R Hemley; K Mao

    2011-12-31T23:59:59.000Z

    The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil cells. The diffraction data for types II (sII) and H (sH) were refined to the known structures with space groups Fd3m and P6{sub 3}/mmc, respectively. Upon compression, sI methanehydrate transforms to the sII phase at 120 MPa, and then to the sH phase at 600 MPa. The sII methanehydrate was found to coexist locally with sI phase up to 500 MPa and with sH phase up to 600 MPa. The pure sH structure was found to be stable between 600 and 900 MPa. Methanehydrate decomposes at pressures above 3 GPa to form methane with the orientationally disordered Fm3mstructure and ice VII (Pn3m). The results highlight the role of guest (CH{sub 4})-host (H{sub 2}O) interactions in the stabilization of the hydratestructures under pressure.

  18. Temporal changes in gas hydrate mound topography and ecology: deep-sea time-lapse camera observations

    E-Print Network [OSTI]

    Vardaro, Michael Fredric

    2004-09-30T23:59:59.000Z

    . This is significant because methane is an important greenhouse gas trapping solar energy and contributing to global warming (Kvenvolden 1999). It has been observed that as water temperature increases gas hydrate begins to dissociate, releasing trapped gas (Mac... (Trehu, et al. 1999). If global warming results in an increase in global ocean temperatures, or if a seismic event destabilizes a large gas hydrate reservoir (Fig. I-3), it could result in the release of gas hydrate-bound methane into the water column...

  19. Study of the hydration of CaO powder by gas-solid reaction 1 , Favergeon.L1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    « Study of the hydration of CaO powder by gas-solid reaction »1 2 3 4 5 6 7 8 9 10 11 12 13 14 15'industrie, B-1400 Nivelles, Belgium Abstract: Hydration of CaO powders by reaction with water vapor has been of the morphological properties on the mechanism of growth of Ca(OH)2. Keywords: A kinetics; A hydration; B

  20. I/I ratios and halogen concentrations in pore waters of the Hydrate Ridge: Relevance for the origin of gas hydrates in ODP Leg 204

    E-Print Network [OSTI]

    Fehn, Udo

    in fluids associated with hydrocarbons, such as oil field brines (Moran et al., 1995) or coal-bed methane association of iodine with methane allows the identification of the organic source material responsible for iodine and methane in gas hydrates. In all cores, iodine concentrations were found to increase strongly

  1. Temperature Dependence of the Hydrophobic Hydration and Interaction of Simple Solutes: An Examination of Five Popular Water Models

    E-Print Network [OSTI]

    Dietmar Paschek

    2004-01-09T23:59:59.000Z

    We examine five different popular rigid water models (SPC, SPCE, TIP3P, TIP4P and TIP5P) using MD simulations in order to investigate the hydrophobic hydration and interaction of apolar Lennard-Jones solutes as a function of temperature in the range between $275 {K}$ and $375 {K}$. For all investigated models and state points we calculate the excess chemical potential for the noble gases and Methane.All water models exhibit too small hydration entropies, but show a clear hierarchy. TIP3P shows poorest agreement with experiment whereas TIP5P is closest to the experimental data at lower temperatures and SPCE is closest at higher temperatures. A rescaling procedure inspired by information theory model of Hummer et al. ({\\em Chem.Phys.}258, 349-370 (2000)) suggests that the differences between the different models and real water can be explained on the basis of the density curves at constant pressure. In addition, the models that give a good representation of the water structure at ambient conditions (TIP5P, SPCE and TIP4P) show considerably better agreement with the experimental data than SPC and TIP3P. We calculate the hydrophobic interaction between Xenon particles directly from a series of 60 ns simulation runs.We find that the temperature dependence of the association is related to the strength of the solvation entropy. Nevertheless, differences between the models seem to require a more detailed molecular picture.The TIP5P model shows by far the strongest temperature dependence.The suggested density-rescaling is also applied to the Xenon-Xenon contact-pair configuration, indicating the presence of a temperature where the hydrophobic interaction turns into purely repulsive.The predicted association for Xenon in real water suggest the presence a strong variation with temperature.

  2. Experimental formation of massive hydrate deposits from accumulation of CH4 gas bubbles within synthetic and natural sediments

    SciTech Connect (OSTI)

    Madden, Megan Elwood [ORNL; Szymcek, Phillip [ORNL; Ulrich, Shannon M [ORNL; McCallum, Scott D [ORNL; Phelps, Tommy Joe [ORNL

    2009-01-01T23:59:59.000Z

    In order for methane to be economically produced from the seafloor, prediction and detection of massive hydrate deposits will be necessary. In many cases, hydrate samples recovered from seafloor sediments appear as veins or nodules, suggesting that there are strong geologic controls on where hydrate is likely to accumulate. Experiments have been conducted examining massive hydrate accumulation from methane gas bubbles within natural and synthetic sediments in a large volume pressure vessels through temperature and pressure data, as well as visual observations. Observations of hydrate growth suggest that accumulation of gas bubbles within void spaces and at sediment interfaces likely results in the formation of massive hydrate deposits. Methane hydrate was first observed as a thin film forming at the gas/water interface of methane bubbles trapped within sediment void spaces. As bubbles accumulated, massive hydrate growth occurred. These experiments suggest that in systems containing free methane gas, bubble pathways and accumulation points likely control the location and habit of massive hydrate deposits.

  3. Toward Production From Gas Hydrates: Current Status, Assessment of Resources, and Simulation-Based Evaluation of Technology and Potential

    E-Print Network [OSTI]

    Moridis, George J.

    2008-01-01T23:59:59.000Z

    to acquire critical reservoir data needed to develop awith synthetic data (describing hydrate reservoirs under thethe flow of reservoir fluids, and (c) data needs that are

  4. Methane Hydrates: Major Energy Source for the Future or Wishful Thinking?

    SciTech Connect (OSTI)

    Thomas, Charles Phillip

    2001-09-01T23:59:59.000Z

    Methane hydrates are methane bearing, ice-like materials that occur in abundance in permafrost areas such as on the North Slope of Alaska and Canada and as well as in offshore continental margin environments throughout the world including the Gulf of Mexico and the East and West Coasts of the United States. Methane hydrate accumulations in the United States are currently estimated to be about 200,000 Tcf, which is enormous when compared to the conventional recoverable resource estimate of 2300 Tcf. On a worldwide basis, the estimate is 700,000 Tcf or about two times the total carbon in coal, oil and conventional gas in the world. The enormous size of this resource, if producible to any degree, has significant implications for U.S. and worldwide clean energy supplies and global environmental issues. Historically the petroleum industry's interests in methane hydrates have primarily been related to safety issues such as wellbore stability while drilling, seafloor stability, platform subsidence, and pipeline plugging. Many questions remain to be answered to determine if any of this potential energy resource is technically and economically viable to produce. Major technical hurdles include: 1) methods to find, characterize, and evaluate the resource; 2) technology to safely and economically produce natural gas from methane hydrate deposits; and 3) safety and seafloor stability issues related to drilling through gas hydrate accumulations to produce conventional oil and gas. The petroleum engineering profession currently deals with gas hydrates in drilling and production operations and will be key to solving the technical and economic problems that must be overcome for methane hydrates to be part of the future energy mix in the world.

  5. Modeling of Oceanic Gas Hydrate Instability and Methane Release in Response to Climate Change

    SciTech Connect (OSTI)

    Reagan, Matthew; Reagan, Matthew T.; Moridis, George J.

    2008-04-15T23:59:59.000Z

    Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating global climate, implicating global oceanic deposits of methane gas hydrate as the main culprit in instances of rapid climate change that have occurred in the past. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid temperature changes, like those predicted under future climate change scenarios, is poorly understood. To determine the fate of the carbon stored in these hydrates, we performed simulations of oceanic gas hydrate accumulations subjected to temperature changes at the seafloor and assessed the potential for methane release into the ocean. Our modeling analysis considered the properties of benthic sediments, the saturation and distribution of the hydrates, the ocean depth, the initial seafloor temperature, and for the first time, estimated the effect of benthic biogeochemical activity. The results show that shallow deposits--such as those found in arctic regions or in the Gulf of Mexico--can undergo rapid dissociation and produce significant methane fluxes of 2 to 13 mol/yr/m{sup 2} over a period of decades, and release up to 1,100 mol of methane per m{sup 2} of seafloor in a century. These fluxes may exceed the ability of the seafloor environment (via anaerobic oxidation of methane) to consume the released methane or sequester the carbon. These results will provide a source term to regional or global climate models in order to assess the coupling of gas hydrate deposits to changes in the global climate.

  6. Guest Molecule Exchange Kinetics for the 2012 Ignik Sikumi Gas Hydrate Field Trial

    SciTech Connect (OSTI)

    White, Mark D.; Lee, Won Suk

    2014-05-14T23:59:59.000Z

    A commercially viable technology for producing methane from natural gas hydrate reservoirs remains elusive. Short-term depressurization field tests have demonstrated the potential for producing natural gas via dissociation of the clathrate structure, but the long-term performance of the depressurization technology ultimately requires a heat source to sustain the dissociation. A decade of laboratory experiments and theoretical studies have demonstrated the exchange of pure CO2 and N2-CO2 mixtures with CH4 in sI gas hydrates, yielding critical information about molecular mechanisms, recoveries, and exchange kinetics. Findings indicated the potential for producing natural gas with little to no production of water and rapid exchange kinetics, generating sufficient interest in the guest-molecule exchange technology for a field test. In 2012 the U.S. DOE/NETL, ConocoPhillips Company, and Japan Oil, Gas and Metals National Corporation jointly sponsored the first field trial of injecting a mixture of N2-CO2 into a CH4-hydrate bearing formation beneath the permafrost on the Alaska North Slope. Known as the Ignik Sikumi #1 Gas Hydrate Field Trial, this experiment involved three stages: 1) the injection of a N2-CO2 mixture into a targeted hydrate-bearing layer, 2) a 4-day pressurized soaking period, and 3) a sustained depressurization and fluid production period. Data collected during the three stages of the field trial were made available after an extensive quality check. These data included continuous temperature and pressure logs, injected and recovered fluid compositions and volumes. The Ignik Sikumi #1 data set is extensive, but contains no direct evidence of the guest-molecule exchange process. This investigation is directed at using numerical simulation to provide an interpretation of the collected data. A numerical simulator, STOMP-HYDT-KE, was recently completed that solves conservation equations for energy, water, mobile fluid guest molecules, and hydrate guest molecules, for up to three gas hydrate guest molecules: CH4, CO2, and N2. The independent tracking of mobile fluid and hydrate guest molecules allows for the kinetic exchange of guest molecules between the mobile fluids and hydrate. The particular interest of this numerical investigation is to determine whether kinetic exchange parameters, determined from laboratory-scale experiments, are directly applicable to interpreting the Ignik Sikumi #1 data.

  7. Polarization and Charge Transfer in the Hydration of Chloride Ions

    E-Print Network [OSTI]

    Zhen Zhao; David M. Rogers; Thomas L. Beck

    2009-12-14T23:59:59.000Z

    A theoretical study of the structural and electronic properties of the chloride ion and water molecules in the first hydration shell is presented. The calculations are performed on an ensemble of configurations obtained from molecular dynamics simulations of a single chloride ion in bulk water. The simulations utilize the polarizable AMOEBA force field for trajectory generation, and MP2-level calculations are performed to examine the electronic structure properties of the ions and surrounding waters in the external field of more distant waters. The ChelpG method is employed to explore the effective charges and dipoles on the chloride ions and first-shell waters. The Quantum Theory of Atoms in Molecules (QTAIM) is further utilized to examine charge transfer from the anion to surrounding water molecules. From the QTAIM analysis, 0.2 elementary charges are transferred from the ion to the first-shell water molecules. The default AMOEBA model overestimates the average dipole moment magnitude of the ion compared with the estimated quantum mechanical value. The average magnitude of the dipole moment of the water molecules in the first shell treated at the MP2 level, with the more distant waters handled with an AMOEBA effective charge model, is 2.67 D. This value is close to the AMOEBA result for first-shell waters (2.72 D) and is slightly reduced from the bulk AMOEBA value (2.78 D). The magnitude of the dipole moment of the water molecules in the first solvation shell is most strongly affected by the local water-water interactions and hydrogen bonds with the second solvation shell, rather than by interactions with the ion.

  8. Hydration of a low-alkali CEM III/B-SiO{sub 2} cement (LAC)

    SciTech Connect (OSTI)

    Lothenbach, Barbara, E-mail: barbara.lothenbach@empa.ch [Empa, Laboratory for Concrete and Construction Chemistry, CH-8600 Duebendorf (Switzerland); Le Saout, Gwenn; Ben Haha, Mohsen; Figi, Renato [Empa, Laboratory for Concrete and Construction Chemistry, CH-8600 Duebendorf (Switzerland); Wieland, Erich [PSI, Laboratory for Waste Management, CH-5232 Villigen PSI (Switzerland)

    2012-02-15T23:59:59.000Z

    The hydration of a low-alkali cement based on CEM III/B blended with 10 wt.% of nanosilica has been studied. The nanosilica reacted within the first days and 90% of the slag reacted within 3.5 years. C-S-H (Ca/Si {approx} 1.2, Al/Si {approx} 0.12), calcite, hydrotalcite, ettringite and possibly straetlingite were the main hydrates. The pore water composition revealed ten times lower alkali concentrations than in Portland cements. Reducing conditions (HS{sup -}) and a pH value of 12.2 were observed. Between 1 month and 3.5 years of hydration more hydrates were formed due to the ongoing slag reaction but no significant differences in the composition of the pore solution or solid phase assemblage were observed. On the basis of thermodynamic calculations it is predicted that siliceous hydrogarnet could form in the long-term and, in the presence of siliceous hydrogarnet, also thaumasite. Nevertheless, even after 3.5 year hydration, neither siliceous hydrogarnet nor thaumasite have been observed.

  9. Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments [Part 1 of 2

    SciTech Connect (OSTI)

    Bryant, Steven; Juanes, Ruben

    2011-12-31T23:59:59.000Z

    In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate saturations. Large volumes (of order one pore volume) of gaseous and aqueous phases must be transported into the gas hydrate stability zone. The driver for this transport is the pressure sink induced by a reduction in occupied pore volume that accompanies the formation of hydrate from gas and water. Pore-scale imbibition models and bed-scale multiphase flow models indicate that the rate-limiting step in converting gas to hydrate is the supply of water to the hydrate stability zone. Moreover, the water supply rate is controlled by capillarity-driven flux for conditions typical of the Alaska North Slope. A meter-scale laboratory experiment confirms that significant volumes of fluid phases move into the hydrate stability zone and that capillarity is essential for the water flux. The model shows that without capillarity-driven flux, large saturations of hydrate cannot form. The observations of thick zones of large saturation at Mallik and Mt Elbert thus suggest that the primary control on these systems is the rate of transport of gaseous and aqueous phases, driven by the pressure sink at the base of the gas hydrate stability zone. A key finding of our project is the elucidation of ?capillary fracturing? as a dominant gas transport mechanism in low-permeability media. We initially investigate this phenomenon by means of grain-scale simulations in which we extended a discrete element mechanics code (PFC, by Itasca) to incorporate the dynamics of first single-phase and then multiphase flow. A reductionist model on a square lattice allows us to determine some of the fundamental dependencies of the mode of gas invasion (capillary fingering, viscous fingering, and fracturing) on the parameters of the system. We then show that the morphology of the gas-invaded region exerts a fundamental control on the fabric of methane hydrate formation, and on the overpressures caused by methane hydrate dissociation. We demonstrate the existence of the different invasion regimes by means of controlled laboratory experiments in a radial cell. We collapse the behavior in the form of a phase di

  10. In-situ early-age hydration study of sulfobelite cements by synchrotron powder diffraction

    SciTech Connect (OSTI)

    Álvarez-Pinazo, G.; Cuesta, A.; García-Maté, M.; Santacruz, I.; Losilla, E.R. [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain)] [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain); Sanfélix, S.G. [Unidad Técnica de Investigación de Materiales, AIDICO, Avda. Benjamín Franklin, 17 Paterna, Valencia (Spain)] [Unidad Técnica de Investigación de Materiales, AIDICO, Avda. Benjamín Franklin, 17 Paterna, Valencia (Spain); Fauth, F. [CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain)] [CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); Aranda, M.A.G. [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain) [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain); CELLS-Alba synchrotron, Carretera BP 1413, Km. 3.3, E-08290 Cerdanyola, Barcelona (Spain); De la Torre, A.G., E-mail: mgd@uma.es [Departamento de Química Inorgánica, Universidad de Málaga, Campus Teatinos S/N., 29071 Málaga (Spain)

    2014-02-15T23:59:59.000Z

    Eco-friendly belite calcium sulfoaluminate (BCSA) cement hydration behavior is not yet well understood. Here, we report an in-situ synchrotron X-ray powder diffraction study for the first hours of hydration of BCSA cements. Rietveld quantitative phase analysis has been used to establish the degree of reaction (?). The hydration of a mixture of ye'elimite and gypsum revealed that ettringite formation (? ? 70% at 50 h) is limited by ye'elimite dissolution. Two laboratory-prepared BCSA cements were also studied: non-active-BCSA and active-BCSA cements, with ?- and ??{sub H}-belite as main phases, respectively. Ye'elimite, in the non-active-BCSA system, dissolves at higher pace (? ? 25% at 1 h) than in the active-BCSA one (? ? 10% at 1 h), with differences in the crystallization of ettringite (? ? 30% and ? ? 5%, respectively). This behavior has strongly affected subsequent belite and ferrite reactivities, yielding stratlingite and other layered phases in non-active-BCSA. The dissolution and crystallization processes are reported and discussed in detail. -- Highlights: •Belite calcium sulfoaluminate cements early hydration mechanism has been determined. •Belite hydration strongly depends on availability of aluminum hydroxide. •Orthorhombic ye’elimite dissolved at a higher pace than cubic one. •Ye’elimite larger reaction degree yields stratlingite formation by belite reaction. •Rietveld method quantified gypsum, anhydrite and bassanite dissolution rates.

  11. Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments [Part 2 of 2

    SciTech Connect (OSTI)

    Bryant, Steven; Juanes, Ruben

    2011-12-31T23:59:59.000Z

    In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate saturations. Large volumes (of order one pore volume) of gaseous and aqueous phases must be transported into the gas hydrate stability zone. The driver for this transport is the pressure sink induced by a reduction in occupied pore volume that accompanies the formation of hydrate from gas and water. Pore-scale imbibition models and bed-scale multiphase flow models indicate that the rate-limiting step in converting gas to hydrate is the supply of water to the hydrate stability zone. Moreover, the water supply rate is controlled by capillarity-driven flux for conditions typical of the Alaska North Slope. A meter-scale laboratory experiment confirms that significant volumes of fluid phases move into the hydrate stability zone and that capillarity is essential for the water flux. The model shows that without capillarity-driven flux, large saturations of hydrate cannot form. The observations of thick zones of large saturation at Mallik and Mt Elbert thus suggest that the primary control on these systems is the rate of transport of gaseous and aqueous phases, driven by the pressure sink at the base of the gas hydrate stability zone. A key finding of our project is the elucidation of ?capillary fracturing? as a dominant gas transport mechanism in low-permeability media. We initially investigate this phenomenon by means of grain-scale simulations in which we extended a discrete element mechanics code (PFC, by Itasca) to incorporate the dynamics of first singlephase and then multiphase flow. A reductionist model on a square lattice allows us to determine some of the fundamental dependencies of the mode of gas invasion (capillary fingering, viscous fingering, and fracturing) on the parameters of the system. We then show that the morphology of the gas-invaded region exerts a fundamental control on the fabric of methane hydrate formation, and on the overpressures caused by methane hydrate dissociation. We demonstrate the existence of the different invasion regimes by means of controlled laboratory experiments in a radial cell. We collapse the behavior in the form of a phase dia

  12. Medium-pressure clathrate hydrate/membrane hybrid process for postcombustion capture of carbon dioxide

    SciTech Connect (OSTI)

    Praveen Linga; Adebola Adeyemo; Peter Englezos [University of British Columbia, Vancouver, BC (Canada). Department of Chemical and Biological Engineering

    2008-01-01T23:59:59.000Z

    This study presents a medium-pressure CO{sub 2} capture process based on hydrate crystallization in the presence of tetrahydrofuran (THF). THF reduces the incipient equilibrium hydrate formation conditions from a CO{sub 2}/N{sub 2} gas mixture. Relevant thermodynamic data at 0.5, 1.0, and 1.5 mol % THF were obtained and reported. In addition, the kinetics of hydrate formation from the CO{sub 2}/N{sub 2}/THF system as well as the CO{sub 2} recovery and separation efficiency were also determined experimentally at 273.75 K. The above data were utilized to develop the block flow diagram of the proposed process. The process involves three hydrate stages coupled with a membrane-based gas separation process. The three hydrate stages operate at 2.5 MPa and 273.75 K. This operating pressure is substantially less than the pressure required in the absence of THF and hence the compression costs are reduced from 75 to 53% of the power produced for a typical 500 MW power plant. 21 refs., 8 figs., 4 tabs.

  13. Cage occupancies in the high pressure structure H methane hydrate: A neutron diffraction study

    SciTech Connect (OSTI)

    Tulk, Christopher A [ORNL; Klug, Dennis D [National Research Council of Canada; Moreira Dos Santos, Antonio F [ORNL; Karotsis, Georgios [ORNL; Guthrie, Malcolm [Carnegie Institution of Washington; Molaison, Jamie J [ORNL; Pradhan, Neelam [ORNL

    2012-01-01T23:59:59.000Z

    A neutron diffraction study was performed on the CD{sub 4}: D{sub 2}O structure H clathrate hydrate to refine its CD{sub 4} fractional cage occupancies. Samples of ice VII and hexagonal (sH) methane hydrate were produced in a Paris-Edinburgh press and in situ neutron diffraction data collected. The data were analyzed with the Rietveld method and yielded average cage occupancies of 3.1 CD{sub 4} molecules in the large 20-hedron (5{sup 12}6{sup 8}) cages of the hydrate unit cell. Each of the pentagonal dodecahedron (5{sup 12}) and 12-hedron (4{sup 3}5{sup 6}6{sup 3}) cages in the sH unit cell are occupied with on average 0.89 and 0.90 CD{sub 4} molecules, respectively. This experiment avoided the co-formation of Ice VI and sH hydrate, this mixture is more difficult to analyze due to the proclivity of ice VI to form highly textured crystals, and overlapping Bragg peaks of the two phases. These results provide essential information for the refinement of intermolecular potential parameters for the water methane hydrophobic interaction in clathrate hydrates and related dense structures.

  14. Composite Thermal Conductivity in a Large Heterogeneous PorousMethane Hydrate Sample

    SciTech Connect (OSTI)

    Gupta, Arvind; Kneafsey, Timothy J.; Moridis George J.; Seol,Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

    2006-08-01T23:59:59.000Z

    By employing inverse modeling to analyze the laboratorydata, we determined the composite thermal conductivity (k theta W/m/K) ofa porous methane hydrate sample ranged between 0.25 and 0.58 W/m/K as afunction of density. The calculated composite thermal diffusivities ofporous hydrate sample ranged between 2.59x10-7 m2/s and 3.71x10-7 m2/s.The laboratory study involved a large heterogeneous sample (composed ofhydrate, water, and methane gas). The measurements were conductedisobarically at 4.98 MPa over a temperature range of 277.3-279.1 K.Pressure and temperature were monitored at multiple locations in thesample. X-ray computed tomography (CT) was used to visualize and quantifythe density changes that occurred during hydrate formation from granularice. CT images showed that methane hydrate formed from granular ice washeterogeneous and provided an estimate of the sample density variation inthe radial direction. This facilitated quantifying the density effect oncomposite thermal conductivity. This study showed that the sampleheterogeneity should be considered in thermal conductivity measurementsof hydrate systems. Mixing models (i.e., arithmetic, harmonic, geometricmean, and square root models) were compared to the estimated compositethermal conductivity determined by inverse modeling. The results of thearithmetic mean model showed the best agreement with the estimatedcomposite thermal conductivity.

  15. Metal halogen battery construction with improved technique for producing halogen hydrate

    DOE Patents [OSTI]

    Fong, Walter L. (Royal Oak, MI); Catherino, Henry A. (Rochester, MI); Kotch, Richard J. (Mt. Clemens, MI)

    1983-01-01T23:59:59.000Z

    An improved electrical energy storage system comprising, at least one cell having a positive electrode and a negative electrode separated by aqueous electrolyte, a store means wherein halogen hydrate is formed and stored as part of an aqueous material having a liquid level near the upper part of the store, means for circulating electrolyte through the cell, conduit means for transmitting halogen gas formed in the cell to a hydrate forming apparatus associated with the store, said hydrate forming apparatus including, a pump to which there is introduced quantities of the halogen gas and chilled water, said pump being located in the store and an outlet conduit leading from the pump and being substantially straight and generally vertically disposed and having an exit discharge into the gas space above the liquid level in the store, and wherein said hydrate forming apparatus is highly efficient and very resistant to plugging or jamming. The disclosure also relates to an improved method for producing chlorine hydrate in zinc chlorine batteries.

  16. Alteration of gas phase ion polarizabilities upon hydration in high dielectric liquids

    E-Print Network [OSTI]

    Sahin Buyukdagli; Tapio Ala-Nissila

    2013-04-23T23:59:59.000Z

    We investigate the modification of gas phase ion polarizabilities upon solvation in polar solvents and ionic liquids. To this aim, we develop a classical electrostatic theory of charged liquids composed of solvent molecules modeled as finite size dipoles, and embedding polarizable ions that consist of Drude oscillators. In qualitative agreement with ab-initio calculations of polar solvents and ionic liquids, the hydration energy of a polarizable ion in both type of dielectric liquid is shown to favor the expansion of its electronic cloud. Namely, the ion carrying no dipole moment in the gas phase acquires a dipole moment in the liquid environment, but its electron cloud also reaches an enhanced rigidity. We find that the overall effect is an increase of the gas phase polarizability upon hydration. In the specific case of ionic liquids, it is shown that this hydration process is driven by a collective solvation mechanism where the dipole moment of a polarizable ion induced by its interaction with surrounding ions self-consistently adds to the polarization of the liquid, thereby amplifying the dielectric permittivity of the medium in a substantial way. We propose this self-consistent hydration as the underlying mechanism behind the high dielectric permittivities of ionic liquids composed of small charges with negligible gas phase dipole moment. Hydration being a correlation effect, the emerging picture indicates that electrostatic correlations cannot be neglected in polarizable liquids.

  17. HOUSING GUARANTEE Apply Online

    E-Print Network [OSTI]

    Mease, Kenneth D.

    THE UCI HOUSING GUARANTEE Apply Online 1 Log in to your MyAdmission account via the tab of Admission fee. 3 Complete the Online Housing Application and pay the $20 non-refundable fee. Freshmen apply for the residence halls. Transfer students apply for Arroyo Vista theme houses and on-campus apartments. Students 25

  18. Application of the Split Hopkinson Resonant Bar Test for Seismic Property Characterization of Hydrate-bearing Sand Undergoing Water Saturation

    SciTech Connect (OSTI)

    Nakagawa, S.; Kneafsey, T.J.

    2011-05-03T23:59:59.000Z

    Conventional resonant bar tests allow the measurement of seismic properties of rocks and sediments at low frequencies (several kilohertz). However, the tests require a long, slender sample which is often difficult to obtain from the deep subsurface and weak and fractured formations. We present an alternative low-frequency measurement technique to the conventional resonant bar tests. This technique involves a jacketed core sample placed between a pair of long, metal extension rods with attached seismic source and receiver—the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the added length and mass to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The proposed “Split Hopkinson Resonant Bar (SHRB)” test is applied in two steps. In the first step, extension and torsion-mode resonance frequencies and attenuation of the system are measured. Then, numerical inversions for the compressional and shear wave velocities and attenuation are performed. We initially applied the SHRB test to synthetic materials (plastics) for testing its accuracy, then used it for measuring the seismic velocities and attenuation of a rock core containing supercritical CO{sub 2}, and a sediment core while methane hydrate formed in the pore space.

  19. Influence of amorphous silica on the hydration in ultra-high performance concrete

    SciTech Connect (OSTI)

    Oertel, Tina, E-mail: tina.oertel@isc.fraunhofer.de [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Inorganic Chemistry I, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth (Germany); Helbig, Uta, E-mail: uta.helbig@th-nuernberg.de [Crystallography and X-ray Methods, Technische Hochschule Nürnberg Georg Simon Ohm, Wassertorstraße 10, 90489 Nürnberg (Germany); Hutter, Frank [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Kletti, Holger [Building Materials, Bauhaus–Universität Weimar, Coudraystr. 11, 99423 Weimar (Germany); Sextl, Gerhard [Fraunhofer–Institute for Silicate Research ISC, Neunerplatz 2, 97082 Würzburg (Germany); Chemical Technology of Advanced Materials, Julius Maximilian Universität, Röntgenring 11, 97070 Würzburg (Germany)

    2014-04-01T23:59:59.000Z

    Amorphous silica particles (silica) are used in ultra-high performance concretes to densify the microstructure and accelerate the clinker hydration. It is still unclear whether silica predominantly increases the surface for the nucleation of C–S–H phases or dissolves and reacts pozzolanically. Furthermore, varying types of silica may have different and time dependent effects on the clinker hydration. The effects of different silica types were compared in this study by calorimetric analysis, scanning and transmission electron microscopy, in situ X-ray diffraction and compressive strength measurements. The silica component was silica fume, pyrogenic silica or silica synthesized by a wet-chemical route (Stoeber particles). Water-to-cement ratios were 0.23. Differences are observed between the silica for short reaction times (up to 3 days). Results indicate that silica fume and pyrogenic silica accelerate alite hydration by increasing the surface for nucleation of C–S–H phases whereas Stoeber particles show no accelerating effect.

  20. Clathrate hydrates as a sink of noble gases in Titan's atmosphere

    E-Print Network [OSTI]

    Thomas, C; Ballenegger, V; Picaud, Sylvain

    2007-01-01T23:59:59.000Z

    We use a statistical thermodynamic approach to determine the composition of clathrate hydrates which may form from a multiple compound gas whose composition is similar to that of Titan's atmosphere. Assuming that noble gases are initially present in this gas phase, we calculate the ratios of xenon, krypton and argon to species trapped in clathrate hydrates. We find that these ratios calculated for xenon and krypton are several orders of magnitude higher than in the coexisting gas at temperature and pressure conditions close to those of Titan's present atmosphere at ground level. Furthermore we show that, by contrast, argon is poorly trapped in these ices. This trapping mechanism implies that the gas-phase is progressively depleted in xenon and krypton when the coexisting clathrate hydrates form whereas the initial abundance of argon remains almost constant. Our results are thus compatible with the deficiency of Titan's atmosphere in xenon and krypton measured by the {\\it Huygens} probe during its descent on J...

  1. Methane Hydrate Dissociation by Depressurization in a Mount Elbert Sandstone Sample: Experimental Observations and Numerical Simulations

    SciTech Connect (OSTI)

    Kneafsey, T.; Moridis, G.J.

    2011-01-15T23:59:59.000Z

    A preserved sample of hydrate-bearing sandstone from the Mount Elbert Test Well was dissociated by depressurization while monitoring the internal temperature of the sample in two locations and the density changes at high spatial resolution using x-ray CT scanning. The sample contained two distinct regions having different porosity and grain size distributions. The hydrate dissociation occurred initially throughout the sample as a result of depressing the pressure below the stability pressure. This initial stage reduced the temperature to the equilibrium point, which was maintained above the ice point. After that, dissociation occurred from the outside in as a result of heat transfer from the controlled temperature bath surrounding the pressure vessel. Numerical modeling of the test using TOUGH+HYDRATE yielded a gas production curve that closely matches the experimentally measured curve.

  2. A Mathematical Model for Predicting the Life of PEM Fuel Cell Membranes Subjected to Hydration Cycling

    E-Print Network [OSTI]

    Burlatsky, S F; O'Neill, J; Atrazhev, V V; Varyukhin, A N; Dmitriev, D V; Erikhman, N S

    2013-01-01T23:59:59.000Z

    Under typical PEM fuel cell operating conditions, part of membrane electrode assembly is subjected to humidity cycling due to variation of inlet gas RH and/or flow rate. Cyclic membrane hydration/dehydration would cause cyclic swelling/shrinking of the unconstrained membrane. In a constrained membrane, it causes cyclic stress resulting in mechanical failure in the area adjacent to the gas inlet. A mathematical modeling framework for prediction of the lifetime of a PEM FC membrane subjected to hydration cycling is developed in this paper. The model predicts membrane lifetime as a function of RH cycling amplitude and membrane mechanical properties. The modeling framework consists of three model components: a fuel cell RH distribution model, a hydration/dehydration induced stress model that predicts stress distribution in the membrane, and a damage accrual model that predicts membrane life-time. Short descriptions of the model components along with overall framework are presented in the paper. The model was used...

  3. Glass durability evaluation using product consistency, single-pass flow-through, and vapor hydration tests

    SciTech Connect (OSTI)

    Feng, X.; Hrma, P.; Kim, D. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1996-12-31T23:59:59.000Z

    The current approach to assessing chemical durability of waste glasses focuses on a suite of short-term laboratory tests such as dynamic single-pass flow-through (SPFT) tests, static product consistency tests (PCT), and vapor hydration tests. The behavior of the glasses in the three types of tests is quite different, but each test provides insight into the glass corrosion process. The PCT data showed that at constant alumina, silica, and sodium levels the glass durability order for different glass systems is: Boron-series > Boron-Calcium-series > Calcium-series, while the opposite order is observed in SPFT tests. The order for vapor hydration tests is similar to that observed in the PCT tests. The PCT results are consistent with the current understanding of glass structure and are consistent with vapor hydration tests. The SPFT results can be explained using arguments based on solution chemistry.

  4. Coalbed Methane Procduced Water Treatment Using Gas Hydrate Formation at the Wellhead

    SciTech Connect (OSTI)

    BC Technologies

    2009-12-30T23:59:59.000Z

    Water associated with coalbed methane (CBM) production is a significant and costly process waste stream, and economic treatment and/or disposal of this water is often the key to successful and profitable CBM development. In the past decade, advances have been made in the treatment of CBM produced water. However, produced water generally must be transported in some fashion to a centralized treatment and/or disposal facility. The cost of transporting this water, whether through the development of a water distribution system or by truck, is often greater than the cost of treatment or disposal. To address this economic issue, BC Technologies (BCT), in collaboration with Oak Ridge National Laboratory (ORNL) and International Petroleum Environmental Consortium (IPEC), proposed developing a mechanical unit that could be used to treat CBM produced water by forming gas hydrates at the wellhead. This process involves creating a gas hydrate, washing it and then disassociating hydrate into water and gas molecules. The application of this technology results in three process streams: purified water, brine, and gas. The purified water can be discharged or reused for a variety of beneficial purposes and the smaller brine can be disposed of using conventional strategies. The overall objectives of this research are to develop a new treatment method for produced water where it could be purified directly at the wellhead, to determine the effectiveness of hydrate formation for the treatment of produced water with proof of concept laboratory experiments, to design a prototype-scale injector and test it in the laboratory under realistic wellhead conditions, and to demonstrate the technology under field conditions. By treating the water on-site, producers could substantially reduce their surface handling costs and economically remove impurities to a quality that would support beneficial use. Batch bench-scale experiments of the hydrate formation process and research conducted at ORNL confirmed the feasibility of the process. However, researchers at BCT were unable to develop equipment suitable for continuous operation and demonstration of the process in the field was not attempted. The significant achievements of the research area: Bench-scale batch results using carbon dioxide indicate >40% of the feed water to the hydrate formation reactor was converted to hydrate in a single pass; The batch results also indicate >23% of the feed water to the hydrate formation reactor (>50% of the hydrate formed) was converted to purified water of a quality suitable for discharge; Continuous discharge and collection of hydrates was achieved at atmospheric pressure. Continuous hydrate formation and collection at atmospheric conditions was the most significant achievement and preliminary economics indicate that if the unit could be made operable, it is potentially economic. However, the inability to continuously separate the hydrate melt fraction left the concept not ready for field demonstration and the project was terminated after Phase Two research.

  5. NICOM 4: 4th International Symposium on Nanotechnology in Construction Effect of Nanosilica on Cement Hydration under High Temperature and

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    ), the silicate polymerization of hydrated cement is investigated. The mi- crostructural compounds in the hardened cement hydration in oil wells is investigated. Cement pastes with water to binder ratio (w/b) of 0- ment pastes was investigated using X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) methods

  6. Assessing the Potential of Using Hydrate Technology to Capture, Store and Transport Gas for the Caribbean Region

    E-Print Network [OSTI]

    Rajnauth, Jerome Joel

    2012-02-14T23:59:59.000Z

    there are infrastructural constraints such as lack of pipelines. The study shows the gas hydrate value chain for transportation of 5 MMscf/d of natural gas from Trinidad to Jamaica. The analysis evaluated the water required for hydrate formation, effect of composition...

  7. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01T23:59:59.000Z

    We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

  8. Estimation of Absolute Free Energies of Hydration using Continuum Methods: Accuracy of Partial Charge Models and Optimization of Nonpolar Contributions

    E-Print Network [OSTI]

    Rizzo, Robert C.

    Estimation of Absolute Free Energies of Hydration using Continuum Methods: Accuracy of Partial, and Irwin D. Kuntz Supporting Information Table S1. Experimental Free Energies of Hydration (Ghyd) in kcal,2-dimethylcyclohexane 1.58 36 trans-1,4-dimethylcyclohexane 2.11 37 ethene 1.28 38 propene 1.32 39 but-1-ene 1.38 40

  9. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

    SciTech Connect (OSTI)

    Rutqvist, J.; Moridis, G.J.; Grover, T.; Collett, T.

    2009-02-01T23:59:59.000Z

    In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900 m at the Mallik and 600 m at the Mount Elbert. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure.

  10. Synthesis and single crystal structure refinement of the one-layer hydrate of sodium brittle mica

    SciTech Connect (OSTI)

    Kalo, Hussein; Milius, Wolfgang [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany)] [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany); Braeu, Michael [BASF Construction Chemicals GmbH, 83308 Trostberg (Germany)] [BASF Construction Chemicals GmbH, 83308 Trostberg (Germany); Breu, Josef, E-mail: Josef.Breu@uni-bayreuth.de [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany)] [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany)

    2013-02-15T23:59:59.000Z

    A sodium brittle mica with the ideal composition [Na{sub 4}]{sup inter}[Mg{sub 6}]{sup oct}[Si{sub 4}Al{sub 4}]{sup tet}O{sub 20}F{sub 4} was synthesized via melt synthesis in a gas tight crucible. This mica is unusual inasmuch as the known mica structure holds only room for two interlayer cations per unit cell and inasmuch as it readily hydrates despite the high layer charge while ordinary micas and brittle micas are non-swelling. The crystal structure of one-layer hydrate sodium brittle mica was determined and refined from single crystal X-ray data. Interlayer cations reside at the center of the distorted hexagonal cavities and are coordinated by the three inner basal oxygen atoms. The coordination of the interlayer cation is completed by three interlayer water molecules residing at the center of the interlayer region. The relative position of adjacent 2:1-layers thus is fixed by these octahedrally coordinated interlayer cations. Pseudo-symmetry leads to extensive twinning. In total five twin operations generate the same environment for the interlayer species and are energetically degenerate. - Graphical abstract: The sodium brittle mica has been successfully synthesized by melt synthesis and the crystal structure of the one-layer hydrate of sodium brittle mica was determined from single crystal X-ray diffraction data. Highlights: Black-Right-Pointing-Pointer Melt synthesis yielded coarse grained sodium brittle mica which showed little disorder. Black-Right-Pointing-Pointer Sodium brittle mica hydrated completely to the state of one-layer hydrate. Black-Right-Pointing-Pointer Structure of one-layer hydrate of sodium brittle mica could therefore be determined and refined. Black-Right-Pointing-Pointer Arrangement of upper and lower tetrahedral sheet encompassing interlayer cation were clarified.

  11. Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, Xiaojing; Nelson, Johanna; Kirz, Janos; Lima, Enju; Marchesini, Stefano; Miao, Huijie; Neiman, Aaron; Shapiro, David; Steinbrener, Jan; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

    2009-11-01T23:59:59.000Z

    We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 degrees C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.

  12. GULF OF MEXICO SEAFLOOR STABILITY AND GAS HYDRATE MONITORING STATION PROJECT

    SciTech Connect (OSTI)

    J. Robert Woolsey; Thomas M. McGee; Robin C. Buchannon

    2004-11-01T23:59:59.000Z

    The gas hydrates research Consortium (HRC), established and administered at the University if Mississippi's Center for Marine Research and Environmental Technology (CMRET) has been active on many fronts in FY 03. Extension of the original contract through March 2004, has allowed completion of many projects that were incomplete at the end of the original project period due, primarily, to severe weather and difficulties in rescheduling test cruises. The primary objective of the Consortium, to design and emplace a remote sea floor station for the monitoring of gas hydrates in the Gulf of Mexico by the year 2005 remains intact. However, the possibility of levering HRC research off of the Joint Industries Program (JIP) became a possibility that has demanded reevaluation of some of the fundamental assumptions of the station format. These provisions are discussed in Appendix A. Landmark achievements of FY03 include: (1) Continuation of Consortium development with new researchers and additional areas of research contribution being incorporated into the project. During this period, NOAA's National Undersea Research Program's (NURP) National Institute for Undersea Science and Technology (NIUST) became a Consortium funding partner, joining DOE and Minerals Management Service (MMS); (2) Very successful annual and semiannual meetings in Oxford Mississippi in February and September, 2003; (3) Collection of piston cores from MC798 in support of the effort to evaluate the site for possible monitoring station installation; (4) Completion of the site evaluation effort including reports of all localities in the northern Gulf of Mexico where hydrates have been documented or are strongly suspected to exist on the sea floor or in the shallow subsurface; (5) Collection and preliminary evaluation of vent gases and core samples of hydrate from sites in Green Canyon and Mississippi Canyon, northern Gulf of Mexico; (6) Monitoring of gas activity on the sea floor, acoustically and thermally; (7) Design, construction, and successful deployment of an in situ pore-water sampling device; (8) Improvements to the original Raman spectrometer (methane sensor); (9) Laboratory demonstration of the impact of bacterially-produced surfactants' rates of hydrate formation; (10) Construction and sea floor emplacement and testing--with both watergun and ship noise sources--of the prototypal vertical line array (VLA); (11) Initiation of studies of spatial controls on hydrates; (12) Compilation and analyses of seismic data, including mapping of surface anomalies; (13) Additional field verification (bottom samples recovered), in support of the site selection effort; (14) Collection and preliminary analyses of gas hydrates from new sites that exhibit variant structures; (15) Initial shear wave tests carried out in shallow water; (16) Isolation of microbes for potential medicinal products development; (17) Preliminary modeling of occurrences of gas hydrates.

  13. Ab initio studies of ionization potentials of hydrated hydroxide and hydronium

    E-Print Network [OSTI]

    Charles W. Swartz; Xifan Wu

    2013-06-04T23:59:59.000Z

    The ionization potential distributions of hydrated hydroxide and hydronium are computed with many-body approach for electron excitations with configurations generated by {\\it ab initio} molecular dynamics. The experimental features are well reproduced and found to be closely related to the molecular excitations. In the stable configurations, the ionization potential is mainly perturbed by water molecules within the first solvation shell. On the other hand, electron excitation is delocalized on both proton receiving and donating complex during proton transfer, which shifts the excitation energies and broadens the spectra for both hydrated ions.

  14. The percolation transition of hydration water: from planar hydrophilic surfaces to proteins

    E-Print Network [OSTI]

    Alla Oleinikova; Ivan Brovchenko; Nikolai Smolin; Aliaksei Krukau; Alfons Geiger; Roland Winter

    2005-08-05T23:59:59.000Z

    The formation of a spanning hydrogen-bonded network of hydration water is found to occur via a 2D percolation transition in various systems: smooth hydrophilic surfaces, the surface of a single protein molecule, protein powder and diluted peptide solution. The average number of water-water hydrogen bonds nH at the percolation threshold varies from 2.0 to 2.3, depending on temperature, system size and surface properties. Calculation of nH allows an easy estimation of the percolation threshold of hydration water in various systems, including biomolecules.

  15. Estimation of composite thermal conductivity of a heterogeneousmethane hydrate sample using iTOUGH2

    SciTech Connect (OSTI)

    Gupta, Arvind; Kneafsey, Timothy J.; Moridis, George J.; Seol,Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

    2006-05-15T23:59:59.000Z

    We determined the composite thermal conductivity (ktheta) ofa porous methanehydrate sample (composedof hydrate, water, and methan egas) as a function of density using iTOUGH2. X-ray computed tomography(CT) was used to visualize and quantify the density changes that occurredduring hydrate formation from granular ice. The composite thermalconductivity was estimated and validated by minimizing the differencesbetween the observed and the predicted thermal response using historymatching. The estimated density-dependent composite thermal conductivityranged between 0.25 and 0.58 W/m/K.

  16. Fundamentals of Natural Gas and Species Flows from Hydrate Dissociation - Applications to Safety and Sea Floor Instability

    SciTech Connect (OSTI)

    Goodarz Ahmadi

    2006-09-30T23:59:59.000Z

    Semi-analytical computational models for natural gas flow in hydrate reservoirs were developed and the effects of variations in porosity and permeability on pressure and temperature profiles and the movement of a dissociation front were studied. Experimental data for variations of gas pressure and temperature during propane hydrate formation and dissociation for crushed ice and mixture of crushed ice and glass beads under laboratory environment were obtained. A thermodynamically consistent model for multiphase liquid-gas flows trough porous media was developed. Numerical models for hydrate dissociation process in one dimensional and axisymmetric reservoir were performed. The computational model solved the general governing equations without the need for linearization. A detail module for multidimensional analysis of hydrate dissociation which make use of the FLUENT code was developed. The new model accounts for gas and liquid water flow and uses the Kim-Boshnoi model for hydrate dissociation.

  17. Influence of polysaccharides on cement hydration PESCHARD A.(1), GOVIN A.(1), FREDON E.(1), GROSSEAU P.(1), FANTOZZI G.(2)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Influence of polysaccharides on cement hydration PESCHARD A.(1), GOVIN A.(1), FREDON E.(1 Cedex, France ABSTRACT This paper is about the influence of polysaccharides on cement hydration. Three media as well as in a dilute media, admixture CE only revealed a slight effect on cement hydration

  18. EXAFS study of Nd(III) uptake by amorphous calcium silicate hydrates (CSH) P. Mandaliev a,b,*, R. Dhn a

    E-Print Network [OSTI]

    Wehrli, Bernhard

    EXAFS study of Nd(III) uptake by amorphous calcium silicate hydrates (C­S­H) P. Mandaliev a,b,*, R Accepted 3 June 2009 Available online 7 June 2009 Keywords: Amorphous calcium silicate hydrate (C Binding mechanisms Molecular level a b s t r a c t Calcium silicate hydrate (C­S­H) phases control

  19. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 757-779, December 2006 Acoustic and Shear-Wave Velocities in Hydrate-Bearing Sediments

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    for the presence of gas hydrate are strong. In this study, we perform velocity analysis of the 6 4-component OBS of the velocities are observed. We then investigate the large scale gas hydrate content through rock physic modeling, and the acoustic veloci- ties predicted for a set of gas hydrate, quartz and clay contents are com- pared

  20. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 933-950, December 2006 Methane Venting in Gas Hydrate Potential Area Offshore of SW

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    933 Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 933-950, December 2006 Methane Venting in Gas Hydrate-mail: tyyang@ntu.edu.tw Water column samples were collected systematically in several poten- tial gas hydrate are considered to have originated from dissociation of gas hydrates and/or a deeper gas reservoir. (Key words

  1. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 829-843, December 2006 Gas Hydrate Stability Zone in Offshore Southern Taiwan

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    829 Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 829-843, December 2006 Gas Hydrate Stability Zone gas (Kvenvolden 1993), there- fore is a very condensed form of gas. The hydrates and any free gas@earth.sinica.edu.tw Methane hydrates are considered a major potential source of hydro- carbon energy and could be important

  2. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 739-756, December 2006 Velocity Structure in Marine Sediments with Gas Hydrate Reflectors

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    Sediments with Gas Hydrate Reflectors in Offshore SW Taiwan, from OBS Data Tomography Win-Bin Cheng 1 be considered a result of local shallowing of the base of the gas hydrate stability zone, caused by ascending structure was ob- served and could be associated with the phenomenon of hydrate/gas phase boundary

  3. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 615-644, December 2006 Distribution and Characters of Gas Hydrate Offshore of

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    of Gas Hydrate Offshore of Southwestern Taiwan Char-Shine Liu 1, *, Philippe Schnürle 1 , Yunshuen Wang 2 reflector (BSR) is a key indicator for the presence of gas hydrate beneath the sea floor. Widely distributed% of the seismic profiles that we collected. A newly compiled BSR distri- bution map suggests that gas hydrates

  4. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 645-658, December 2006 The Geological Structure and Prospect of Gas Hydrate

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    and Prospect of Gas Hydrate over the Dongsha Slope, South China Sea Pin Yan 1, 2, *, Hui Deng 1 , and Hailing of Marginal Sea Geology, Chinese Academy of Sciences, Guangzhou, China 2 Guangzhou Center for Gas Hydrate for the occurrence of gas hydrate related features, like BSR, cold seep carbonates and chemoautotrophic bacteria

  5. Derivation of a Langmuir type of model to describe the intrinsic growth rate of gas hydrates during crystallization from gas mixtures

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Derivation of a Langmuir type of model to describe the intrinsic growth rate of gas hydrates during de Saint-Etienne, 158 Cours Fauriel, 42023 Saint- Etienne, France Abstract Gas Hydrates 81 (2012) 28-37" DOI : 10.1016/j.ces.2012.06.016 #12;Keywords Gas Hydrates, Crystallisation

  6. Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, 781-797, December 2006 Seismic Data Processing and the Characterization of a Gas Hydrate

    E-Print Network [OSTI]

    Lin, Andrew Tien-Shun

    and the Characterization of a Gas Hydrate Bearing Zone Offshore of Southwestern Taiwan Hui Deng 1, 2, 4, 5, *, Pin Yan 1, 3, Guangzhou, China 3 Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou, China, Guangzhou, China; E-mail: nhsdenghui@163.com Various seismic attributes of gas hydrate bearing sediments

  7. Applied Computer Science

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Science and Innovation Computing CCS Division CCS-7 Applied Computer Science Innovative co-design of applications, algorithms, and architectures in order to enable...

  8. Apply early! Limited enrollment.

    E-Print Network [OSTI]

    volcano. Experience the culture and history of Hawaii, and the impact of human activitiesApply early! Limited enrollment. Environmental Science in the Hawaiian Islands Observe, research

  9. Selecting and Applying Interfacings

    E-Print Network [OSTI]

    2006-05-01T23:59:59.000Z

    Selecting and using interfacing correctly is an important component of garment construction. The various types of interfacing are described and methods of applying them are discussed in detail....

  10. INTRODUCTION APPLIED GEOPHYSICS

    E-Print Network [OSTI]

    Merriam, James

    GEOL 384.3 INTRODUCTION TO APPLIED GEOPHYSICS OUTLINE INTRODUCTION TO APPLIED GEOPHYSICS GEOL 384 unknowns; the ones we don't know we don't know. And if one looks throughout the history of geophysics he didn't really say geophysics. He said, " ... our country and other free countries ...". But I am

  11. Alkaline stability of cellulose ethers and impact of their degradation products on cement hydration

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Alkaline stability of cellulose ethers and impact of their degradation products on cement-mail address: pourchez@emse.fr emse-00449712,version1-18Sep2010 Author manuscript, published in "Cement the potential role of cellulose ethers degradation on the alteration of the cement hydration kinetics

  12. On the initial stages of cement hydration S. J. Preece, J. Billingham and A. C. King

    E-Print Network [OSTI]

    Billingham, John

    On the initial stages of cement hydration S. J. Preece, J. Billingham and A. C. King School the initial mixing of cement, an induction period occurs during which its consistency remains constant- stituent of cement, which is believed to be responsible for the initial development of its strength. Our

  13. A multiphase model for the early stages of the hydration of retarded oilwell cement

    E-Print Network [OSTI]

    Billingham, John

    A multiphase model for the early stages of the hydration of retarded oilwell cement J. Billingham, Birmingham B15 2TT, UK A.M. Harrisson The Rugby Group, RMC House Rugby CV21 2DT, UK Abstract. Cement is used in the oil industry to line oil wells. The major com- ponents of oilwell cement are tricalcium silicate (C3S

  14. In situ molecular imaging of hydrated biofilm in a microfluidic reactor by ToF-SIMS

    SciTech Connect (OSTI)

    Hua, Xin; Yu, Xiao-Ying; Wang, Zhaoying; Yang, Li; Liu, Bingwen; Zhu, Zihua; Tucker, Abigail E.; Chrisler, William B.; Hill, Eric A.; Thevuthasan, Suntharampillai; Lin, Yuehe; Liu, Songqin; Marshall, Matthew J.

    2014-02-26T23:59:59.000Z

    The first results of using a novel single channel microfluidic reactor to enable Shewanella biofilm growth and in situ characterization using time-of-flight secondary ion mass spectrometry (ToF-SIMS) in the hydrated environment are presented. The new microfluidic interface allows direct probing of the liquid surface using ToF-SIMS, a vacuum surface technique. The detection window is an aperture of 2 m in diameter on a thin silicon nitride (SiN) membrane and it allows direct detection of the liquid surface. Surface tension of the liquid flowing inside the microchannel holds the liquid within the aperture. ToF-SIMS depth profiling was used to drill through the SiN membrane and the biofilm grown on the substrate. In situ 2D imaging of the biofilm in hydrated state was acquired, providing spatial distribution of the chemical compounds in the biofilm system. This data was compared with a medium filled microfluidic reactor devoid of biofilm and dried biofilm samples deposited on clean silicon wafers. Principle Component Analysis (PCA) was used to investigate these observations. Our results show that imaging biofilms in the hydrated environment using ToF-SIMS is possible using the unique microfluidic reactor. Moreover, characteristic biofilm fatty acids fragments were observed in the hydrated biofilm grown in the microfluidic channel, illustrating the advantage of imaging biofilm in its native environment.

  15. The Use of Horizontal Wells in Gas Production from Hydrate Accumulations

    SciTech Connect (OSTI)

    Reagan, Matthew; Moridis, George J.; Reagan, Matthew T.; Zhang, Keni

    2008-04-15T23:59:59.000Z

    The amounts of hydrocarbon gases trapped in natural hydrate accumulations are enormous, leading to a recent interest in the evaluation of their potential as an energy source. Earlier studies have demonstrated that large volumes of gas can be readily produced at high rates for long times from gas hydrate accumulations by means of depressurization-induced dissociation, using conventional technology and vertical wells. The results of this numerical study indicate that the use of horizontal wells does not confer any practical advantages to gas production from Class 1 deposits. This is because of the large disparity in permeabilities between the hydrate layer (HL) and the underlying free gas zone, leading to a hydrate dissociation that proceeds in a horizontally dominant direction and is uniform along the length of the reservoir. When horizontal wells are placed near the base of the HL in Class 2 deposits, the delay in the evolution of a significant gas production rate outweighs their advantages, which include higher rates and the prevention of flow obstruction problems that often hamper the performance of vertical wells. Conversely, placement of a horizontal well near to top of the HL can lead to dramatic increases in gas production from Class 2 and Class 3 deposits over the corresponding production from vertical wells.

  16. Feasibility of monitoring gas hydrate production with time-lapse VSP

    SciTech Connect (OSTI)

    Kowalsky, M.B.; Nakagawa, S.; Moridis, G.J.

    2009-11-01T23:59:59.000Z

    In this work we begin to examine the feasibility of using time-lapse seismic methods-specifically the vertical seismic profiling (VSP) method-for monitoring changes in hydrate accumulations that are predicted to occur during production of natural gas.

  17. Strength and hydration properties of reactive MgO-activated ground granulated blastfurnace slag paste

    E-Print Network [OSTI]

    Jin, Fei; Gu, Kai; Al-Tabbaa, Abir

    2014-12-10T23:59:59.000Z

    on the Siemens D5000 X-ray diffractometer using a scanning range from 5 to 60 (2?), with scanning speed of 2 s/step and resolution of 0.05 °/step to identify the hydration products formed. TGA was conducted on PerkinElmer STA6000 equipment from 40 to 1000 °C...

  18. The thermodynamics of proton hydration and the electrochemical surface potential of water

    SciTech Connect (OSTI)

    Pollard, Travis P. [Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221 (United States); Beck, Thomas L. [Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221 (United States); Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States)

    2014-11-14T23:59:59.000Z

    The free energy change for transferring a single ion across the water liquid/vapor interface includes an electrochemical surface potential contribution. Since this potential is not directly accessible to thermodynamic measurement, several extra-thermodynamic approaches have been employed to infer its sign and magnitude, with a resulting wide spread of values. Here, we examine further the thermodynamics of proton hydration and the electrochemical surface potential of water along three directions: (1) a basic relation of interfacial electrostatics and experimental results on ion distributions near a water/organic interface are employed to infer a solvent contribution to the electrochemical surface potential, (2) a re-analysis is performed of the existing bulk and cluster ion hydration data, and (3) extensive computational modeling is conducted to examine the size dependence of hydration enthalpy differences for the NaF ion pair between the small cluster and the converged bulk limits. The computational studies include classical polarizable models and high-level quantum chemical methods. The new theoretical analysis of existing experimental data and the combined classical/quantum modeling lead to results consistent with our previously derived proton hydration quantities.

  19. In silico studies of the properties of water hydrating a small protein

    SciTech Connect (OSTI)

    Sinha, Sudipta Kumar; Chakraborty, Kausik; Bandyopadhyay, Sanjoy, E-mail: sanjoy@chem.iitkgp.ernet.in [Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur - 721302 (India); Jana, Madhurima [Molecular Simulation Laboratory, Department of Chemistry, National Institute of Technology, Rourkela - 769008 (India)

    2014-12-14T23:59:59.000Z

    Atomistic molecular dynamics simulation of an aqueous solution of the small protein HP-36 has been carried out with explicit solvent at room temperature. Efforts have been made to explore the influence of the protein on the relative packing and ordering of water molecules around its secondary structures, namely, three ?-helices. The calculations reveal that the inhomogeneous water ordering and density distributions around the helices are correlated with their relative hydrophobicity. Importantly, we have identified the existence of a narrow relatively dehydrated region containing randomly organized “quasi-free” water molecules beyond the first layer of “bound” waters at the protein surface. These water molecules with relatively weaker binding energies form the transition state separating the “bound” and “free” water molecules at the interface. Further, increased contribution of solid-like caging motions of water molecules around the protein is found to be responsible for reduced fluidity of the hydration layer. Interestingly, we notice that the hydration layer of helix-3 is more fluidic with relatively higher entropy as compared to the hydration layers of the other two helical segments. Such characteristics of helix-3 hydration layer correlate well with the activity of HP-36, as helix-3 contains the active site of the protein.

  20. Electromagnetic detection of plate hydration due to bending faults at the Middle America Trench

    E-Print Network [OSTI]

    Constable, Steve

    images show that the extensive network of trench parallel normal faults penetrates the entire oceanic bending faults on the incoming oceanic plate of the Middle America Trench offshore Nicaragua have been observed to penetrate to mantle depths, suggesting a permeable pathway for hydration of the crust