Development and validation of an acoustic-electrical joint testing system for hydrate-bearing porous media

Acoustic and electrical properties are fundamental and important physical properties to characterize hydrate-bearing sediments. A new experimental system called Ultrasound Combined with Electrical Impedance was developed for jointly testing the ultrasonic wave parameters and electrical impedance of hydrate-bearing porous media in the hydrate formation and decomposition processes. The Ultrasound Combined with Electrical Impedance system features its novel ultrasonic-electrical compound sensors and sensor array, fully controllable instruments, variety of sampled data, and flexible working modes. Experiment was carried out with methane gas as the hydrate former, meanwhile the acoustic/electrical parameters were derived. The acoustic/electrical properties were characterized with the aid of typical models such as the time-average equation, Wood’s equation, weighted equation, and Archie’s formula. It has been shown by the results that key parameters such as the sound velocity and electrical impedance can be used to characterize the acoustic and electrical properties of hydrate-bearing sediments conjointly, demonstrating the applicability of the proposed Ultrasound Combined with Electrical Impedance system. The wavelet-analysis based denoising approach and singularity detection method are effective denoising methods to filter the ultrasound signals and to identify the arriving time of the ultrasonic wave. The weighted equation and Archie’s formula with a segmented regression method are recommended for modeling the relations between the hydrate saturation and sound velocity/impedance modulus, respectively.

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Maximum Sizes of Fluid-Occupied Pores within Hydrate-Bearing Porous Media Composed of Different Host Particles

Geofluids ◽

10.1155/2020/8880286 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

Lele Liu ◽

Nengyou Wu ◽

Changling Liu ◽

Qingguo Meng ◽

Haitao Tian ◽

...

Keyword(s):

Porous Media ◽

Fractal Theory ◽

Hydrate Formation ◽

Maximum Size ◽

Theoretical Models ◽

Equivalent Diameter ◽

Pore Filling ◽

Particle Properties ◽

Hydrate Saturation ◽

Hydrate Bearing Sediments

Hydraulic properties of hydrate-bearing sediments are largely affected by the maximum size of pores occupied by fluids. However, effects of host particle properties on the maximum size of fluid-occupied pores within hydrate-bearing sediments remain elusive, and differences in the maximum equivalent, incircle, and hydraulic diameters of fluid-occupied pores evolving with hydrate saturation have not been well understood. In this study, numerical simulations of grain-coating and pore-filling hydrate nucleation and growth within different artificial porous media are performed to quantify the maximum equivalent, incircle, and hydraulic diameters of fluid-occupied pores during hydrate formation, and how maximum diameters of fluid-occupied pores change with hydrate saturation is analyzed. Then, theoretical models of geometry factors for incircle and hydraulic diameters are proposed based on fractal theory, and variations of fluid-occupied pore shapes during hydrate formation are discussed. Results show that host particle properties have obvious effects on the intrinsic maximum diameters of fluid-occupied pores and introduce discrepancies in evolutions of the maximum pore diameters during hydrate formation. Pore-filling hydrates reduce the maximum incircle and hydraulic diameters of fluid-occupied pores much more significantly than grain-coating hydrates; however, hydrate pore habits have minor effects on the maximum equivalent diameter reduction. Shapes of fluid-occupied pores change little due to the presence of grain-coating hydrates, but pore-filling hydrates lead to much fibrous shapes of fluid-occupied pores.

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Memory effect of CO2-hydrate formation in porous media

Fuel ◽

10.1016/j.fuel.2021.120922 ◽

2021 ◽

Vol 299 ◽

pp. 120922

Author(s):

Zhiang Wen ◽

Yanbin Yao ◽

Wanjing Luo ◽

Xin Lei

Keyword(s):

Porous Media ◽

Memory Effect ◽

Hydrate Formation

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Electrical Impedance Spectroscopy as Electrical Biopsy for Monitoring Radiation Sequelae of Intestine in Rats

BioMed Research International ◽

10.1155/2013/974614 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

Pei-Ju Chao ◽

Eng-Yen Huang ◽

Kuo-Sheng Cheng ◽

Yu-Jie Huang

Keyword(s):

Electrical Properties ◽

Impedance Spectroscopy ◽

Integrated Circuits ◽

Electrical Impedance ◽

Roc Analysis ◽

Electrical Impedance Spectroscopy ◽

Electrical Characteristics ◽

Injury Score ◽

Histological Changes ◽

Radiation Sequelae

Electrical impedance is one of the most frequently used parameters for characterizing material properties. The resistive and capacitive characteristics of tissue may be revealed by electrical impedance spectroscopy (EIS) as electrical biopsy. This technique could be used to monitor the sequelae after irradiation. In this study, rat intestinal tissues after irradiation were assessed by EIS system based on commercially available integrated circuits. The EIS results were fitted to a resistor-capacitor circuit model to determine the electrical properties of the tissue. The variations in the electrical characteristics of the tissue were compared to radiation injury score (RIS) by morphological and histological findings. The electrical properties, based on receiver operation curve (ROC) analysis, strongly reflected the histological changes with excellent diagnosis performance. The results of this study suggest that electrical biopsy reflects histological changes after irradiation. This approach may significantly augment the evaluation of tissue after irradiation. It could provide rapid results for decision making in monitoring radiation sequelae prospectively.

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Characterization of the Muscle Electrical Properties in Low Back Pain Patients by Electrical Impedance Myography

PLoS ONE ◽

10.1371/journal.pone.0061639 ◽

2013 ◽

Vol 8 (4) ◽

pp. e61639 ◽

Cited By ~ 10

Author(s):

Congo Tak-Shing Ching ◽

Yueh-Chi Chen ◽

Li-Hua Lu ◽

Peiyuan F. Hsieh ◽

Chin-Sung Hsiao ◽

...

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Electrical Properties ◽

Electrical Impedance ◽

Low Back ◽

Pain Patients

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Permeability Analysis of Hydrate-Bearing Sediments during the Hydrate Formation Process

Energy & Fuels ◽

10.1021/acs.energyfuels.1c02913 ◽

2021 ◽

Author(s):

Min Li ◽

Peng Wu ◽

Shanshan Zhou ◽

Lunxiang Zhang ◽

Lei Yang ◽

...

Keyword(s):

Formation Process ◽

Hydrate Formation ◽

Hydrate Bearing Sediments ◽

Hydrate Formation Process

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Quantification of methane hydrate formation in the Large-scale Reservoir Laboratory Simulator (LARS) by numerical simulations

10.5194/egusphere-egu21-1312 ◽

2021 ◽

Author(s):

Zhen Li ◽

Thomas Kempka ◽

Erik Spangenberg ◽

Judith Schicks

Keyword(s):

Gas Hydrates ◽

Methane Hydrate ◽

Large Scale ◽

Hydrate Formation ◽

Simulation Environment ◽

Transport Simulation ◽

Chemistry Research ◽

Research Activities ◽

In Situ Conditions ◽

Hydrate Bearing Sediments

Natural gas hydrates are considered as one of the most promising alternatives to conventional fossil energy sources, and are thus subject to world-wide research activities for decades. Hydrate formation from methane dissolved in brine is a geogenic process, resulting in the accumulation of gas hydrates in sedimentary formations below the seabed or overlain by permafrost. The LArge scale Reservoir Simulator (LARS) has been developed (Schicks et al., 2011, 2013; Spangenberg et al., 2015) to investigate the formation and dissociation of gas hydrates under simulated in-situ conditions of hydrate deposits. Experimental measurements of the temperatures and bulk saturation of methane hydrates by electrical resistivity tomography have been used to determine the key parameters, describing and characterising methane hydrate formation dynamics in LARS. In the present study, a framework of equations of state to simulate equilibrium methane hydrate formation in LARS has been developed and coupled with the TRANsport Simulation Environment (Kempka, 2020) to study the dynamics of methane hydrate formation and quantify changes in the porous medium properties in LARS. We present our model implementation, its validation against TOUGH-HYDRATE (Gamwo & Liu, 2010) and the findings of the model comparison against the hydrate formation experiments undertaken by Priegnitz et al. (2015). The latter demonstrates that our numerical model implementation is capable of reproducing the main processes of hydrate formation in LARS, and thus may be applied for experiment design as well as to investigate the process of hydrate formation at specific geological settings.Key words: dissolved methane; hydrate formation; hydration; python; permeability.ReferencesSchicks, J. M., Spangenberg, E., Giese, R., Steinhauer, B., Klump, J., & Luzi, M. (2011). New approaches for the production of hydrocarbons from hydrate bearing sediments. Energies, 4(1), 151-172, https://doi.org/10.3390/en4010151Schicks, J. M., Spangenberg, E., Giese, R., Luzi-Helbing, M., Priegnitz, M., & Beeskow-Strauch, B. (2013). A counter-current heat-exchange reactor for the thermal stimulation of hydrate-bearing sediments. Energies, 6(6), 3002-3016, https://doi.org/10.3390/en6063002Spangenberg, E., Priegnitz, M., Heeschen, K., & Schicks, J. M. (2015). Are laboratory-formed hydrate-bearing systems analogous to those in nature?. Journal of Chemical & Engineering Data, 60(2), 258-268, https://doi.org/10.1021/je5005609Kempka, T. (2020) Verification of a Python-based TRANsport Simulation Environment for density-driven fluid flow and coupled transport of heat and chemical species. Adv. Geosci., 54, 67&#8211;77, https://doi.org/10.5194/adgeo-54-67-2020Gamwo, I. K., & Liu, Y. (2010). Mathematical modeling and numerical simulation of methane production in a hydrate reservoir. Industrial & Engineering Chemistry Research, 49(11), 5231-5245, https://doi.org/10.1021/ie901452vPriegnitz, M., Thaler, J., Spangenberg, E., Schicks, J. M., Schr&#246;tter, J., & Abendroth, S. (2015). Characterizing electrical properties and permeability changes of hydrate bearing sediments using ERT data. Geophysical Journal International, 202(3), 1599-1612, https://doi.org/10.1093/gji/ggv245

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Effect of Ultrasonic Treatment on Radon Exhalation from Porous Media: An Experimental Case Study

Sustainability ◽

10.3390/su10093005 ◽

2018 ◽

Vol 10 (9) ◽

pp. 3005

Author(s):

Ling-feng Xie ◽

Shu-liang Zou ◽

Xiang-yang Li ◽

Chang-shou Hong ◽

Hong Wang ◽

...

Keyword(s):

Porous Media ◽

Moisture Content ◽

Ultrasonic Wave ◽

Linear Correlation ◽

Experimental Results ◽

Radon Exhalation Rate ◽

Exhalation Rate ◽

Radon Exhalation ◽

Experimental Apparatus ◽

Positive Linear Correlation

Radon is internationally recognized as one of the seven seismic precursors. A self-assembly ultrasonic generator and experimental apparatus for radon measurement were utilized to explore the radon exhalation regularities of water-bearing porous media under different ultrasonic intensities. The experimental results showed that there was a coupling relationship among radon exhalation rate, moisture content, and ultrasonic frequency. With the increase of the frequency of the ultrasonic wave, its effect on the promotion of radon exhalation rate was found to be a more obviously positive linear correlation. The radon exhalation rate, which could climb to a maximum value of 0.179 Bq·m−2·s−1 in a naturally air-dried sample, increased at first and then decreased along with increased moisture content. Moreover, this study found that the ultrasonic wave had the most remarkable promoting effects on the radon exhalation rate of porous media with high moisture content, and there is a positive linear correlation between the growth rate of the radon exhalation rate and moisture content. The experimental results could provide a beneficial reference for the continual monitoring of radon in a seismically active belt and an explanation of radon anomalies; however, the proposed experimental model was simplified, so further insights are strictly required for a reliable correlation with the real monitoring of radon in a seismically active belt.

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