Prediction Performance of Permeability Models in Gas-Hydrate-Bearing Sands

Mohana L. Delli; Jocelyn L.H. Grozic

doi:10.2118/149508-pa

Prediction Performance of Permeability Models in Gas-Hydrate-Bearing Sands

SPE Journal ◽

10.2118/149508-pa ◽

2013 ◽

Vol 18 (02) ◽

pp. 274-284 ◽

Cited By ~ 29

Author(s):

Mohana L. Delli ◽

Jocelyn L.H. Grozic

Keyword(s):

Gas Hydrate ◽

Hybrid Approach ◽

Hydrate Formation ◽

Field Studies ◽

Graphical Analysis ◽

Performance Measure ◽

Prediction Performance ◽

Permeability Model ◽

Hydrate Saturation ◽

Sediment Reduction

Summary Permeability variation in the presence of gas hydrates (GH) is a major unknown in modeling hydrate dissociation in gas-hydrate-bearing sediment. Reduction of permeability in porous media occurs as a result of decreased porosity because of hydrate formation within pore spaces. In the absence of reliable experimental data, theoretical and empirical models have been proposed to establish the relationship between gas-hydrate saturation and permeability. The effectiveness of a particular permeability model in fitting the measured data has largely been qualitative through graphical analysis. In contrast, this paper introduces a quantitative performance measure to evaluate the effectiveness of an individual model in predicting the measured permeability. Second, a hybrid approach based on the weighted combination of existing permeability models is proposed. Permeability measurements from experimental and field studies were used to assess the prediction performance of various permeability models and the proposed hybrid approach.

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Mathematical modelling of injection gas hydrate formation into the massif of snow saturated the same gas

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2016.2.034 ◽

2016 ◽

Vol 11 (2) ◽

pp. 233-239 ◽

Cited By ~ 2

Author(s):

V.Sh. Shagapov ◽

A.S. Chiglintseva ◽

S.V. Belova

Keyword(s):

Diffusion Coefficient ◽

Mathematical Modelling ◽

Gas Hydrate ◽

Hydrate Formation ◽

Influence Analysis ◽

Hydrate Layer ◽

Gas Hydrate Formation ◽

Hydrate Saturation ◽

The Given ◽

Cold Gas

Considered the problem of gas hydrate formation during injection of cold gas in the snow massif, initially saturated with the same gas. In work some limited scheme according to which, intensity of hydrate formation is limited by diffusion of gas through the hydrate layer formed between the phases of gas and ice, to the boundary of contact ice-hydrate, and is determined by the introduction of only one parameter the given diffusion coefficient. Shows the distributions of pressure, temperature, hydrate saturation and the saturation of the snow at different points in time. Held influence analysis of the effect of the pressure of the injected gas and the permeability of the snow massif on the intensity of hydrate formation.

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Gas hydrate in-situ formation and dissociation in clayey-silt sediments: An investigation by low-field NMR

Energy Exploration & Exploitation ◽

10.1177/0144598720974159 ◽

2020 ◽

pp. 014459872097415

Author(s):

Xiaoxiao Sun ◽

Xuwen Qin ◽

Hongfeng Lu ◽

Jingli Wang ◽

Jianchun Xu ◽

...

Keyword(s):

Gas Hydrate ◽

Hydrate Formation ◽

Dissociation Process ◽

Hydrate Dissociation ◽

Hydrate Reservoir ◽

Low Field ◽

Gas Hydrate Formation ◽

Clayey Silt ◽

Hydrate Saturation ◽

Low Field Nmr

The hydrate reservoir in the Shenhu Area of the South China Sea is a typical clayey-silt porous media with high clay mineral content and poor cementation, in which gas hydrate formation and dissociation characteristics are unclear. In this study, the CO2 hydrate saturation, growth rate, and permeability were studied in sandstone, artificial samples, and clayey-silt sediments using a custom-built measurement apparatus based on the low-field NMR technique. Results show that the T2 spectra amplitudes decrease with the hydrate formation and increase with the dissociation process. For the artificial samples and Shenhu sediments, the CO2 hydrate occupies larger pores first and the homogeneity of the sandstone pores becomes poor. Meanwhile, compared with the clayey-silt sediments, CO2 hydrate is easier to form and with higher hydrate saturation for the sandstone and artificial samples. In hydrate dissociation process, there exists a protection mechanism, i.e. the dissociation near the center of hydrates grain is suppressed when gas pressure drops suddenly and quickly. For permeability of those samples, it decreased with hydrate forms, and increases with hydrate dissociation. Meanwhile, with the same hydrate saturation, permeability is higher in hydrate formation than in dissociation.

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Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

Biogeosciences Discussions ◽

10.5194/bgd-8-4529-2011 ◽

2011 ◽

Vol 8 (3) ◽

pp. 4529-4558 ◽

Cited By ~ 2

Author(s):

K. Heeschen ◽

M. Haeckel ◽

I. Klaucke ◽

M. K. Ivanov ◽

G. Bohrmann

Keyword(s):

Black Sea ◽

Gas Hydrate ◽

Pore Volume ◽

Sediment Cores ◽

Stability Boundary ◽

Hydrate Formation ◽

Gas Hydrate Formation ◽

Hydrate Saturation ◽

Gas Volume

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponds to concentrations of 1.2–1.4 mol of methane per kg porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolves the upper gas hydrate stability boundary and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume can be calculated. This is higher in comparison to a saturation calculated from the Cl− profile alone, resulting in 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

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Modelling Methane Hydrate Saturation in Pores: Capillary Inhibition Effects

Energies ◽

10.3390/en14185627 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5627

Author(s):

Maria De La Fuente ◽

Jean Vaunat ◽

Héctor Marín-Moreno

Keyword(s):

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Gas Hydrate ◽

Hydrate Formation ◽

Clapeyron Equation ◽

Fine Grained ◽

Chemical Potentials ◽

Hydrate Saturation ◽

Global Inventory

Experimental and field observations evidence the effects of capillarity in narrow pores on inhibiting the thermodynamic stability of gas hydrates and controlling their saturation. Thus, precise estimates of the gas hydrate global inventory require models that accurately describe gas hydrate stability in sediments. Here, an equilibrium model for hydrate formation in sediments that accounts for capillary inhibition effects is developed and validated against experimental data. Analogous to water freezing in pores, the model assumes that hydrate formation is controlled by the sediment pore size distribution and the balance of capillary forces at the hydrate–liquid interface. To build the formulation, we first derive the Clausius–Clapeyron equation for the thermodynamic equilibrium of methane and water chemical potentials. Then, this equation is combined with the van Genuchten’s capillary pressure to relate the thermodynamic properties of the system to the sediment pore size distribution and hydrate saturation. The model examines the influence of the sediment pore size distribution on hydrate saturation through the simulation of hydrate formation in sand, silt, and clays, under equilibrium conditions and without mass transfer limitations. The results show that at pressure–temperature conditions typically found in the seabed, capillary effects in very fine-grained clays can limit the maximum hydrate saturation below 20% of the host sediment porosity.

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A State-Dependent Constitutive Model for Gas Hydrate-Bearing Sediments Considering Cementing Effect

Journal of Marine Science and Engineering ◽

10.3390/jmse8080621 ◽

2020 ◽

Vol 8 (8) ◽

pp. 621

Author(s):

Qingmeng Yuan ◽

Liang Kong ◽

Rui Xu ◽

Yapeng Zhao

Keyword(s):

Constitutive Model ◽

Gas Hydrate ◽

Prediction Performance ◽

Strain Behavior ◽

Mixed Hardening ◽

Hardening Law ◽

State Dependent ◽

Hydrate Saturation ◽

Hardening Theory ◽

Hydrate Bearing Sediments

This paper presents a state-dependent constitutive model for gas hydrate-bearing sediments (GHBS), considering the cementing effect for simulating the stress–strain behavior of GHBS. In this work, to consider the influence of hydrate on matrix samples in theory, some representative GHBS laboratory tests were analyzed, and it was found that GHBS has obvious state-related characteristics. At the same time, it was found that GHBS has high bonding strength. In order to describe these characteristics of GHBS, the cementation strength related to hydrate saturation is introduced in the framework of a sand state correlation model. In addition, in order to accurately reflect the influence of cementation on the hardening law of GHBS, the degradation rate of cementation strength is introduced, and the mixed hardening theory is adopted to establish the constitutive model. The model presented in this paper reproduces the experimental results of Masui et al. and Miyazaki et al., and the prediction performance of the model is satisfactory, which proves the rationality of this work.

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Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

Biogeosciences ◽

10.5194/bg-8-3555-2011 ◽

2011 ◽

Vol 8 (12) ◽

pp. 3555-3565 ◽

Cited By ~ 15

Author(s):

K. U. Heeschen ◽

M. Haeckel ◽

I. Klaucke ◽

M. K. Ivanov ◽

G. Bohrmann

Keyword(s):

Black Sea ◽

Gas Hydrate ◽

Pore Volume ◽

Sediment Cores ◽

Hydrate Formation ◽

Gas Hydrate Formation ◽

Hydrate Saturation ◽

Gas Volume ◽

Quantifying In

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.2–1.4 mol CH4 kg−1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolved the upper boundary of gas hydrate occurrence and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume could be calculated. This volume was higher in comparison to a saturation calculated from the Cl− profile alone, resulting in only 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

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Methane hydrate saturations at the Southern Hikurangi margin (New Zealand) estimated from seismic and rock physics inversion

10.5194/egusphere-egu2020-11486 ◽

2020 ◽

Author(s):

Francesco Turco ◽

Andrew Gorman ◽

Gareth Crutchley ◽

Leonardo Azevedo ◽

Dario Grana ◽

...

Keyword(s):

New Zealand ◽

Gas Hydrate ◽

Methane Hydrate ◽

Waveform Inversion ◽

Hydrate Formation ◽

Rock Physics ◽

Stability Zone ◽

Hydrate Saturation ◽

Physics Model ◽

Hydrate Stability

Geophysical data indicate that the Hikurangi subduction margin on New Zealand&#8217;s East Coast contains a large gas hydrate province. Gas hydrates are widespread in shallow sediments across the margin, and locally intense fluid seepage associated with methane hydrate is observed in several areas. Glendhu and Honeycomb ridges lie at the toe of the Hikurangi deformation wedge at depths ranging from 2100 to 2800 m. These two parallel four-way closure systems host concentrated methane hydrate deposits. The control on hydrate formation at these ridges is governed by steeply dipping permeable strata and fractures, which allow methane to flow upwards into the gas hydrate stability zone. Hydrate recycling at the base of the hydrate stability zone may contribute to the accumulation of highly concentrated hydrate in porous layers. To improve the characterisation of the hydrate systems at Glendhu and Honeycomb ridges, we estimate hydrate saturation and porosity of the concentrated hydrate deposits. We first estimate elastic properties (density, compressional and shear-wave velocities) of the gas hydrate stability zone through full-waveform inversion and iterative geostatistical seismic amplitude versus angle (AVA) inversion. We then perform a petrophysical inversion based on a rock physics model to predict gas hydrate saturation and porosity of the hydrate bearing sediments along the two ridges. Our results indicate that the high seismic amplitudes correspond to the top interface of highly concentrated hydrate deposit, with peak saturations around 35%. Because of the resolution of the seismic data we assume that the estimated properties are averaged over layers of 10 to 20 meters thickness. These saturation values are in agreement with studies conducted in other areas of concentrated hydrate accumulations in similar geologic settings.

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In Situ Measurement of Electrical Resistivity of Ocean Sediments Containing Gas Hydrates

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.432.104 ◽

2013 ◽

Vol 432 ◽

pp. 104-108 ◽

Cited By ~ 3

Author(s):

Yu Feng Chen ◽

De Qing Liang ◽

Neng You Wu

Keyword(s):

Electrical Resistivity ◽

Gas Hydrate ◽

Hydrate Formation ◽

Pore Fluid ◽

Natural Gas Hydrate ◽

Resistivity Index ◽

Ocean Sediment ◽

Hydrate Saturation ◽

Water Saturated

An understanding of the physical properties of hydrate-bearing sediment is necessary for interpretation of geophysical data collected in field settings. We have conducted a laboratory experiment to measure the electrical property of initially water saturated sediment containing natural gas hydrate. When gas hydrate was formed from pore fluid in ocean sediment, bulk sediment resistivity was significantly increased. The resistivity of the sediment was largely changed below 20% hydrate saturation. With the increasing hydrate saturation, the resistivity of sediment was increased and the resistivity of pore fluid was decrease. In the final process of hydrate formation, the resistivity depression was found mainly due to the transition of gas hydrate morphology. The electrical resistivity of hydrate specimens varied from 1.930 Ohm.m to 3.950 Ohm.m for saturation ranging from 0% to 52.68%. Besides, the dependence of the resistivity index versus hydrate saturation is inconsistent with Archies law. The results of our studies have important implications for quantitative laboratory and field calibration of geophysical measurements within gas hydratebearing intervals.

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