Electrical conductivity of methane hydrate with pore fluids: new results from the lab

Lu, R; Stern, L A; Du Frane, W L; Pinkston, J C; Constable, S

Title: Electrical conductivity of methane hydrate with pore fluids: new results from the lab

Full Record
Other Related Research

Abstract

With renewed U.S. Department of Energy (DOE) support to characterize the evolution of gas hydrate systems using marine electromagnetic (EM) methods paired with laboratory studies, we extended previous electrical conductivity measurements on methane hydrate, with and without sediment, to include a liquid component. Here we report the pronounced effects of adding pure H₂O water or NaCl-bearing brine, and we track the development of the fluid phase within samples. Pure H₂O pore water, generated in situ through partial dissociation of methane hydrate at 5°C, increases conductivity by at least a factor of 3 (0.5 on a log scale), as water accumulates in roughly 15 ± 5 vol.% of the sample. Brine, generated by adding NaCl to sample reactants prior to methane hydrate synthesis, elicited a considerably stronger effect; at 5°C, the addition of 2.5wt% NaCl increases conductivity by over 2 orders of magnitude (log-scale) relative to pure methane hydrate. Cryogenic scanning electron microscopy (cryo-SEM) imaging of quenched samples revealed the distribution of the liquid component within samples, thus allowing evaluation of conduction mechanisms and pathways.

Authors:

Lu, R ^[1]; Stern, L A ^[2]; Du Frane, W L ^[1]; Pinkston, J C ^[2]; Constable, S ^[3]

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
U.S. Geological Survey, Menlo Park, CA (United States)
Univ. of California, San Diego, CA (United States). Scripps Inst. of Oceanography

Publication Date:: Fri Aug 24 00:00:00 EDT 2018

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:: 1491627

Report Number(s):: LLNL-JRNL-751643
Journal ID: ISSN 9999-0027; 937485

Grant/Contract Number:: AC52-07NA27344; FE0028972; FE0026382

Resource Type:: Accepted Manuscript

Journal Name:: Methane Hydrate News

Additional Journal Information:: Journal Volume: vol. 18; Journal Issue: no. 1; Journal ID: ISSN 9999-0027

Publisher:: US Department of Energy. National Energy Technology Laboratory

Country of Publication:: United States

Language:: English

Subject:: 58 GEOSCIENCES

Citation Formats


                    Lu, R, Stern, L A, Du Frane, W L, Pinkston, J C, and Constable, S. Electrical conductivity of methane hydrate with pore fluids: new results from the lab.  United States: N. p., 2018. 
Web.

Copy to clipboard


                    Lu, R, Stern, L A, Du Frane, W L, Pinkston, J C, & Constable, S. Electrical conductivity of methane hydrate with pore fluids: new results from the lab.  United States.

Copy to clipboard


                    Lu, R, Stern, L A, Du Frane, W L, Pinkston, J C, and Constable, S. Fri .  
"Electrical conductivity of methane hydrate with pore fluids: new results from the lab".  United States.  https://www.osti.gov/servlets/purl/1491627.

Copy to clipboard


                    
@article{osti_1491627,

  title        = {Electrical conductivity of methane hydrate with pore fluids: new results from the lab},

  author       = {Lu, R and Stern, L A and Du Frane, W L and Pinkston, J C and Constable, S},

  abstractNote = {With renewed U.S. Department of Energy (DOE) support to characterize the evolution of gas hydrate systems using marine electromagnetic (EM) methods paired with laboratory studies, we extended previous electrical conductivity measurements on methane hydrate, with and without sediment, to include a liquid component. Here we report the pronounced effects of adding pure H2O water or NaCl-bearing brine, and we track the development of the fluid phase within samples. Pure H2O pore water, generated in situ through partial dissociation of methane hydrate at 5°C, increases conductivity by at least a factor of 3 (0.5 on a log scale), as water accumulates in roughly 15 ± 5 vol.% of the sample. Brine, generated by adding NaCl to sample reactants prior to methane hydrate synthesis, elicited a considerably stronger effect; at 5°C, the addition of 2.5wt% NaCl increases conductivity by over 2 orders of magnitude (log-scale) relative to pure methane hydrate. Cryogenic scanning electron microscopy (cryo-SEM) imaging of quenched samples revealed the distribution of the liquid component within samples, thus allowing evaluation of conduction mechanisms and pathways.},

  doi          = {},

  journal      = {Methane Hydrate News},

  number       = no. 1,

  volume       = vol. 18,

  place        = {United States},

  year         = {Fri Aug 24 00:00:00 EDT 2018},

  month        = {Fri Aug 24 00:00:00 EDT 2018}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

The DOI is not currently available

Other availability

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

The Effect of Brine on the Electrical Properties of Methane Hydrate

Journal Article Lu, R. ; Stern, L. A. ; Du Frane, W. L. ; ... - Journal of Geophysical Research. Solid Earth

Gas hydrates possess lower electrical conductivity (inverse of resistivity) than either seawater or ice, but higher than clastic silts and sands, such that electromagnetic methods can be employed to help identify their natural formation in marine and permafrost environments. Controlled laboratory studies offer a means to isolate and quantify the effects of changing individual components within gas-hydrate-bearing systems, in turn yielding insight into the behavior of natural systems. Here we investigate the electrical properties of polycrystalline methane hydrate with ≥25% gas-filled porosity and in mixture with brine. Initially, pure methane hydrate was synthesized from H2O ice and CH4 gas whilemore »« less
Cited by 12
https://doi.org/10.1029/2019JB018364

Full Text Available
Characterizing Baselines and Change in Gas Hydrate Systems using EM Methods

Technical Report Constable, Steven R. ; Kannberg, Peter K. ; Stern, Laura A. ; ...

The objective of this project was to advance our understanding of gas hydrate systems in nature by characterizing their electrical properties in the field and in the laboratory. In the laboratory measurements, methane hydrate was synthesized from pure water ice and flash frozen seawater, with varying amounts of sand or silt added. Electrical conductivity was determined by impedance spectroscopy, using equivalent circuit modeling to separate the effects of electrodes and to gain insight into conduction mechanisms. Silt and sand increase the conductivity of pure hydrate, inferred to be contaminant NaCl contributing to conduction in hydrate, to a peak conductivity inmore »« less
https://doi.org/10.2172/1608233

Full Text Available
Electrical Properties of Carbon Dioxide Hydrate: Implications for Monitoring CO₂ in the Gas Hydrate Stability Zone

Journal Article Stern, Laura A. ; Constable, Steven ; Lu, Ryan ; ... - Geophysical Research Letters

Abstract CO ₂ and CH ₄ clathrate hydrates are of keen interest for energy and carbon cycle considerations. While both typically form on Earth as cubic structure I (sI), we find that pure CO ₂ hydrate exhibits over an order of magnitude higher electrical conductivity ( σ ) than pure CH ₄ hydrate at geologically relevant temperatures. The conductivity was obtained from frequency‐dependent impedance ( Z ) measurements made on polycrystalline CO ₂ hydrate (CO ₂ ·6.0 ± 0.2H ₂ O by methods here) with 25% gas‐filled porosity, compared with CH ₄ hydrate (CH ₄ ·5.9H ₂ O) formed and measured inmore »« less
https://doi.org/10.1029/2021gl093475

Full Text Available
CO₂ Hydrate: Synthesis, Composition, Structure, Dissociation Behavior, and a Comparison to Structure I CH₄ Hydrate

Journal Article Circone, S. ; Stern, Laura A. ; Kirby, Stephen H. ; ... - Journal of Physical Chemistry B

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 untilmore »« less
https://doi.org/10.1021/jp027391j
Radiation chemistry of salt-mine brines and hydrates. [Gamma radiation]

Technical Report Jenks, G H ; Walton, J R ; Bronstein, H R ; ...

Certain aspects of the radiation chemistry of NaCl-saturated MgCl/sub 2/ solutions and MgCl/sub 2/ hydrates at temperatures in the range of 30 to 180/sup 0/C were investigated through experiments. A principal objective was to establish the values for the yields of H/sub 2/ (G(H/sub 2/)) and accompanying oxidants in the gamma-ray radiolysis of concentrated brines that might occur in waste repositories in salt. We concluded that G(H/sub 2/) from gamma-irradiated brine solution into a simultaneously irradiated, deaerated atmosphere above the solution is between 0.48 and 0.49 over most of the range 30 to 143/sup 0/C. The yield is probably somewhatmore »« less
https://doi.org/10.2172/6345215

Full Text Available

Similar Records