Study of CCl3F hydrate formation and dissociation in W/O emulsion by differential scanning calorimetry and X-ray diffraction

Fouconnier, Benoît; Komunjer, L.; Ollivon, Michel; Lesieur, P.; Keller, G.; Clausse, Danièle

doi:10.1016/j.fluid.2006.10.006

Cited by 25 publications

(21 citation statements)

References 19 publications

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“…7 and 8, we see that the hybrid modeling predicts the hydrate formation to progress from the grain-coating to the pore-filling behavior with increasing hydrate saturations. While synthetic hydrate using R-11 can be formed at atmospheric pressure at temperatures between 2 and 8 C (Fouconnier et al 2006), CO 2 hydrates requires an equilibrium pressure of 2 MPa or higher [2.76 MPa was used by Kumar et al (2010)] at a temperature of around 4 C. It is interesting to note that the hydrate formed with R-11 and CO 2 exhibited similar formation behavior despite having different guest gas molecules, hydrate structures, and pressure conditions. The hybrid modeling predicted a progressive change from grain-coating to pore-filling behavior, yielding a permeability reduction that lies between these models.…”

Section: Permeability Analysis Of Laboratory-synthesized Samplesmentioning

confidence: 99%

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

Delli

Grozic

2013

SPE Journal

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Permeability variation in the presence of gas hydrates (GH) is a major unknown in modeling hydrate dissociation in gas-hydratebearing 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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Section: Permeability Analysis Of Laboratory-synthesized Samplesmentioning

confidence: 99%

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

Delli

Grozic

2013

SPE Journal

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“…Furthermore, most drilling fluids in deepwater offshore drilling facilities, where hydrate plugging hazards may occur because of low seabed temperatures, are in forms of water‐in‐oil emulsions 3. Hence, understanding the characteristic of hydrate formation in water‐in‐oil emulsions has drawn much attention in recent years 4–14…”

Section: Introductionmentioning

confidence: 99%

“…With in‐depth studies on hydrate formation/dissociation in water‐in‐oil emulsions, the relevant experimental techniques such as the differential scanning calorimetry (DSC),3, 5–8 X‐ray diffraction,9, 10 nuclear magnetic resonance (NMR),11 particle video microscope (PVM), focused beam reflectance measurement (FBRM),12 and dielectric spectroscopy13, 14 have been used to characterize hydrate formation in water‐in‐oil emulsions. Dalmazzone et al5 measured the dissociation of methane hydrate in water‐in‐oil emulsion systems using the DSC technique and pressure vs. temperature measurements in a constant volume cell (pressure–volume–temperature, PVT).…”

Section: Introductionmentioning

confidence: 99%

Metastable boundary conditions of water‐in‐oil emulsions in the hydrate formation region

et al. 2011

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A stepwise pressurization method was proposed for determining the metastable boundary conditions of water-in-oil emulsions in the hydrate formation region. The metastable boundary pressures of four water-in-n-octane emulsions in the presence of methane gas were determined at four specified temperatures. The experimental results show that the metastable boundary pressures increase with decreasing water droplet sizes. A thermodynamic model was developed for calculating the metastable boundary conditions of a water-in-oil emulsion in which assuming that the collapse of a metastable emulsion requires the formation of a stable hydrate film with a critical thickness on the surfaces of water droplets. The model was used to correlate the experimental data and determine the critical thickness of the hydrate film. It was demonstrated that the calculated results were in good agreement with the experimental data. The determined critical thickness is at nanoscale, ranging from 14 to 40 nm, which decreases with decreasing water droplet sizes.

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“…CCl 3 F is a volatile liquid poorly soluble in water and forms a hydrate under mild conditions at 8.5°C and 1 bar. Therefore, CCl 3 F appeared to be a good candidate in order to mimic the conditions of gas hydrate formation in W/O emulsions as a model system (Jakobsen et al 1996;Fouconnier et al 1999Fouconnier et al , 2006. The solid hydrate phase is formed inside the dispersed droplets as the result of a chemical reaction between CCl 3 F molecules and water molecules present in the droplets.…”

Section: Mass Transfer Within Simple Emulsions Solid Ripening In W/omentioning

confidence: 99%

“…Hydrate formation was not detected during the cooling. Therefore, in order to evidence the conditions of the CCl 3 F hydrate formation in W/O emulsions, a study using DSC and X-ray diffraction has been undertaken (Fouconnier et al 2006). It has been concluded that a high degree of undercooling results in a spontaneous ice formation in the droplets during cooling of the emulsions.…”

Section: Mechanisms Of Hydrate Formation In W/o Emulsionsmentioning

confidence: 99%