Experimental Measurement of Gas-Liquid Diffusivity

Policarpo, Nara Angélica; Ribeiro, Paulo Leonardo Lima

doi:10.5419/bjpg2011-0017

Cited by 18 publications

(11 citation statements)

References 15 publications

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“…(It must be greater than 1 3c and the time where experimental data starts decaying exponentially). The Levenberg-Marquardt method (Press et al 1996) has been used for nonlinear regression. The comparison between model results and experimental data is plotted in Figs.…”

Section: Resultsmentioning

confidence: 99%

“…Molecular diffusion is one of the core transport phenomena in various disciplines of science and engineering, including chemical engineering (Jackson 1977;Froment and Bischoff 1979;Bird et al 2001;Ratnakar and Balakotaiah 2014), polymer science (Neogi 1996), biology (Adelstein and Manning 1995;Anthea et al 1997), combustion technology (Harstad and Bellan 2004), automobile industry (Heck and Farrauto 2009;Kumar et al 2014), and petroleum engineering, including tertiary recovery in carbon dioxide (CO 2 ) flooding (Stalkup 1970;Huang and Tracht 1974;Shelton and Schneider 1975;Grogan and Pinczewski 1987;Yanze and Clemens 2012), vapor-assisted petroleum extraction (VAPEX) (Boustani and Maini 2001;Yang and Gu 2006), solution-gas-drive process (Li and Yortsos 1995), drilling fluid (Policarpo and Ribeiro 2011), acid fracturing (Ratnakar et al , 2013, and many more. In petroleum-engineering applications, molecular diffusion plays a very important role in various reservoir processes, especially in the oil-recovery processes where convective forces are not dominant or when direct frontal contact and mixing are not possible.…”

Section: Introductionmentioning

confidence: 99%

“…Thus accurate determination of this key parameter is essential to design and understand displacement processes. In addition, diffusive mixing also plays a crucial role in drilling operations (Policarpo and Ribeiro 2011). One of the main functions of drilling fluid is to exert hydrostatic pressure on the formation to prevent the influx of formation fluids into the wellbore.…”

Section: Introductionmentioning

confidence: 99%

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Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments

Ratnakar

Dindoruk

2015

SPE Journal

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Molecular diffusion plays a very important role in various reservoir processes, especially in the oil-recovery processes where convective forces are not dominant or when direct frontal contact and mixing are not possible. For example, in heavy-oil and bitumen recovery, injected light hydrocarbons can diffuse into the oil beyond the potential fronts and/or convective zones and promote the effectiveness of the displacement process, reducing in-situ viscosities and in turn enhancing the oil recovery.Similarly, diffusive mixing can also be a dominant mechanism in the gas-redissolution process, even in lighter-hydrocarbon systems. For example, it controls how much gas will be dissolved in oil and how long it will take to dissolve, in the absence of mechanical/convective mixing, as in the case of reservoir repressurization. The extent of dissolution of a gas into oil is governed by its solubility, but the rate is controlled by both molecular diffusivity and solubility. Thus, accurate determination of these parameters is essential to design and understand displacement processes.Despite the significance of diffusion in various aspects of oil recovery, there are very few experimental studies available in the literature addressing the diffusion of gas in heavy oils. Experimental work is most commonly based on the pressure-decay concept. However, the parameter inversion in these tests relies on an error-function solution that neglects the transient processes at the gas/oil interface and assumes constant-saturation concentration. This assumption is not appropriate when decay in pressure is large because pressure in the gas cap changes continuously as gas is dissolved in the oil, and hence the gas solubility varies with time. One of the major issues related to this experimental process is that it takes a long time (order of several days to several months) to achieve steady-state (converged) solution to determine diffusivity.In this work, we have • Experimentally investigated the diffusion of methane in heavy oils as well as light oils by use of a pressure-decay test • Captured properly the variation in gas concentration in oil at the gas/oil interface with time by expressing gas solubility in terms of Henry's constant in the mathematical model • Developed the exact solution of the 1D pressure-decay (transient-diffusion) model with pressure-dependent gas/oilinterface concentration and shown that after a long time, pressure decays exponentially in time with an exponent that depends on diffusivity as well as solubility • Presented the inversion technique to determine the diffusivity and other parameters from late-transient-pressure data, and shown the convergence in their estimates • (Most importantly) developed a cutoff criterion permitting us to stop the experiments while still being able to extract the converged diffusivity values (this is important in situations when the experiment is stopped prematurely for technical or other reasons)

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments

Ratnakar

Dindoruk

2015

SPE Journal

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“…Molecular diffusion is one of the core transport phenomenon in various disciplines of science and engineering, including chemical engineering [1][2][3][4] , polymer science [5] , Biology [6][7] , combustion technology [8] , automobile industries [9][10][11] , petroleum engineering (tertiary recovery in CO2 flooding [12][13][14][15][16] ; Vapex [17][18] ; solution gas drive process [19] ; drilling fluid [20] ; acid fracturing [21][22] ) and many more. In Petroleum engineering applications, the molecular diffusion plays a very important role in various reservoir processes; especially in the oil recovery processes where convective forces are not dominant or when direct frontal contact and mixing is not possible.…”

Section: Introductionmentioning

confidence: 99%

“…Thus accurate determination of this key parameter is essential to design and understand displacement processes. In addition, the diffusive mixing also plays a crucial role in drilling operations [20] .One of the main functions of drilling fluid is to exert hydrostatic pressure on formation to prevent the influx of formation fluids into the wellbore. However, during drilling, gases from the formation can be mixed with the drilling fluid due to failures in the operation, such as insufficient fluid weight and circulation loss.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Gas Diffusivity in Heavy Oils/Bitumens using Pressure-Decay Test

Ratnakar

Dindoruk

2014

All Days

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Molecular diffusion plays a very important role in various reservoir processes; especially in the oil recovery processes where convective forces are not dominant or when direct frontal contact and mixing is not possible. For example, in heavy oil and bitumen recovery, injected light hydrocarbons can diffuse into the oil beyond the potential fronts and/or convective zones and promote the effectiveness of the displacement process, and therefore, reduce in-situ viscosities which in turn enhance the oil recovery.Similarly, diffusive mixing can also be a dominant mechanism in the gas re-dissolution process even in lighter hydrocarbon systems. For example, it controls how much gas will be dissolved in oil and how long it will take to dissolve, in the absence of mechanical/convective mixing, as in the case of reservoir re-pressurization. The extent of dissolution of a gas into oil is governed by its solubility but the rate is controlled by molecular diffusivity and solubility, both. Thus accurate determination of these parameters is essential to design and understand displacement processes.Despite the significance of diffusion in various aspects of oil recovery, there are very few experimental studies available in the literature addressing the diffusion of gas in heavy oils. Experimental work is most commonly based on the Pressure-decay concept. However, the parameter inversion in these tests relies on an error function solution that neglects the transient processes at the gas-oil interface and assumes constant saturation concentration. This assumption is not appropriate because pressure in the gas cap changes continuously as gas is dissolved in the oil and hence the gas solubility varies with time. One of the major issues related to this experimental process is that it takes a long time (order of several days to few months) to achieve steady state (converged) solution to determine diffusivity.In this work, we have 1. Experimentally investigated the diffusion of methane in heavy oils as well as light oils using pressure-decay test; 2. Captured the transient effect at the gas-oil interface transient properly by expressing gas solubility in terms of Henry's constant in the model (1-dimensional diffusion equation coupled with pressure decline due to gas dissolution); 3. Developed the exact solution of the model and shown that after long time, pressure decays exponentially in time with an exponent that depends on diffusivity as well as solubility;4. Presented the inversion technique, determined the diffusivity and other parameters from late transient pressure data, and showed the convergence in their estimates; and, 5. Most importantly, we have developed a cut off criterion permitting us to stop the experiments while still being able to extract the converged diffusivity values (this is important in situations when the experiment is stopped prematurely for technical or other reasons).

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Experimental determination of CO₂ diffusion coefficient in aqueous solutions under pressure at room temperature via Raman spectroscopy: impact of salinity (NaCl)

Belgodere

Dubessy

Vautrin

et al. 2015

J Raman Spectroscopy

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The accurate determination of the diffusion coefficient of dissolved CO2 in aqueous solutions is a key parameter to predict the transport of the dissolved gas in the aqueous solution of porous aquifers and caprocks in the context of the mitigation of greenhouse gases emissions. A better understanding of the diffusion kinetics of dissolved CO2 as a function of subsurface conditions is essential to ensure the integrity of CO2 storage in saline aquifers. Experimental data are available to predict the CO2 diffusion kinetics as a function of temperature and pressure. However, the impact of salinity on CO2 diffusivity is still poorly documented. In this work, the diffusion coefficients of dissolved CO2 were determined using in situ Raman microspectrometry in Fused Silica Capillaries in a range of salinity from 0.0 to 6.0 molNaCl kg−1H2O. The diffusion coefficient of CO2 dissolved in pure water at 21 ± 1 °C and 40 bar is 1.71 × 10−9 ± 0.06 m2 s−1. In the same conditions of pressure and temperature, the diffusion coefficient of dissolved CO2 decreases with salinity increase: from 0.0 to 6.0 molNaCl kg−1H2O (the diffusion kinetics of dissolved CO2 is divided by two). Consequently, the impact of salinity on the diffusion coefficient of dissolved CO2 must be taken into account to evaluate the transport of dissolved gases in the brine of the reservoir and caprock. Copyright © 2015 John Wiley & Sons, Ltd.

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Experimental Measurement of Gas-Liquid Diffusivity

Cited by 18 publications

References 15 publications

Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments

Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments

Measurement of Gas Diffusivity in Heavy Oils/Bitumens using Pressure-Decay Test

Experimental determination of CO₂ diffusion coefficient in aqueous solutions under pressure at room temperature via Raman spectroscopy: impact of salinity (NaCl)

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Experimental Measurement of Gas-Liquid Diffusivity

Cited by 18 publications

References 15 publications

Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments

Measurement of Gas Diffusivity in Heavy Oils and Bitumens by Use of Pressure-Decay Test and Establishment of Minimum Time Criteria for Experiments

Measurement of Gas Diffusivity in Heavy Oils/Bitumens using Pressure-Decay Test

Experimental determination of CO2 diffusion coefficient in aqueous solutions under pressure at room temperature via Raman spectroscopy: impact of salinity (NaCl)

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About

Experimental determination of CO₂ diffusion coefficient in aqueous solutions under pressure at room temperature via Raman spectroscopy: impact of salinity (NaCl)