Estimation of concentration‐dependent diffusion coefficients of gases in heavy oils/bitumen using experimental pressure‐decay data

Roman, Francisco Javier Pacheco; Hejazi, S. Hossein

doi:10.1002/cjce.22606

Cited by 16 publications

(7 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A good agreement between the experimental results and the fit can be seen for all sugars based on the respective R 2 . This is in line with results from research in petrochemical industry where an exponential dependency between diffusion coefficient and concentration described the experimental results better than a constant or a power law approach , . It is worth stressing that the strong influence of increased viscosity assumed in Eq.…”

Section: Resultssupporting

confidence: 88%

See 1 more Smart Citation

Diffusion Studies of Glucose and Sucrose in Chitosan Membranes and Beads for Enzymatic Production Processes

et al. 2018

View full text Add to dashboard Cite

The diffusion of glucose and sucrose was investigated in membrane and bead experiments. Concentration-dependent diffusion coefficients of pure glucose and sucrose were determined in precipitated chitosan membranes of varying thickness using diffusion cell experiments. Contrary to fructose, the resulting diffusion coefficients of glucose and sucrose did not reach their free diffusion coefficients at infinite dilution suggesting additional interactions between chitosan and these two sugars. Counter-diffusion in bead experiments showed a good agreement between predicted and measured data allowing the inclusion of the diffusion data in the simulation of the proposed production process for laminaribiose. In conclusion, the encapsulation in chitosan presented a good trade-off between increased mass transfer resistance as evaluated by the Thiele modulus and improved thermal stability and antibacterial activity.

show abstract

Section: Resultssupporting

confidence: 88%

“…Concentration‐dependent diffusion coefficients are mostly discussed in the context of petrochemical processes for diffusion of gases through heavy oil or bitumen . Here, an exponential decay is applied to describe the dimensionless viscosity µ* :

true μ * = \frac{μ}{μ_{1}} = e^{S (1 - c *)}

…”

Section: Theorymentioning

confidence: 99%

Diffusion Studies of Glucose and Sucrose in Chitosan Membranes and Beads for Enzymatic Production Processes

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Significant changes in the diffusivity of the solvent and bitumen with composition were first noted by Oballa and Butler, and a variety of forms of the composition dependence have been reported. − Some of the reported trends were physically implausible with a maximum diffusivity at intermediate concentrations and/or diffusivities higher than the self-diffusion coefficient of the solvent. The nonphysical trends are likely artifacts arising from the method used to analyze the diffusion data. − An exponential relationship of diffusivity with the solvent concentration has been used to model pressure decay experiments with plausible diffusivity values. , This relationship has been shown to be equivalent to a power law relationship to viscosity, , which has also been used to model pressure decay experiments …”

Section: Introductionmentioning

confidence: 99%

“…30−32 An exponential relationship of diffusivity with the solvent concentration has been used to model pressure decay experiments with plausible diffusivity values. 26,27 This relationship has been shown to be equivalent to a power law relationship to viscosity, 27,29 which has also been used to model pressure decay experiments. 28 Recently, Richardson et al 33 proposed a set of correlations to determine the diffusivity of gases in bitumen as a function of viscosity (see Section 3.1).…”

Section: Introductionmentioning

confidence: 99%

Correlation for the Diffusivity of Gaseous and Liquid Hydrocarbons with Bitumen

et al. 2021

View full text Add to dashboard Cite

The oil production rate of in situ heavy oil recovery processes involving the injection of gaseous or liquid hydrocarbon solvents depends strongly on the mutual diffusivity of the solvent and bitumen. Data for these diffusivities, particularly above the ambient temperature, are relatively scarce because they are time-consuming to measure. In this study, the diffusion and solubilities of gaseous toluene, n-pentane, and n-heptane in a Western Canadian bitumen and its maltenes were measured at temperatures from 150 to 180 °C using a pressure decay method. The diffusivities were determined as a function of viscosity from a numerical model of the experiments. A previously developed correlation for the infinite dilution viscosity of solvent into bitumen, originally proposed for gas/bitumen systems with low solvent solubility in bitumen, was extended to higher solubility gases and to liquid hydrocarbon/bitumen systems. The correlation was updated using gas/bitumen diffusivities and liquid hydrocarbon/bitumen diffusivities from the literature, and the gas/bitumen data were obtained in this study. Tuned correlation parameters for solvent diffusion in bitumen and in maltenes are provided. The numerical model with the proposed correlations matches the measured cumulative mass transfer from the pressure decay experiments in this study to within ±18% and the measured concentration profiles from liquid solvent/crude oil experiments to within ±4 wt %.

show abstract

“…More practically, the diffusion coefficient is concentration‐dependent (CDC) for a binary miscible system, proved by a series of experiments . The different diffusion–concentration relations have been previously examined . Different with the diffusion, the dispersion is however strongly velocity‐induced (VID) .…”

Section: Introductionmentioning

confidence: 99%

Control of viscous fingering and mixing in miscible displacements with time‐dependent rates

et al. 2018

View full text Add to dashboard Cite

In miscible displacements encountered in enhanced oil recovery processes, the unfavorable viscosity contrast between injected solvent and oil usually leads to viscous fingering (VF), a hydrodynamic instability which may result in a lower sweep efficiency and oil recovery. This phenomenon can be observed in a wide range of flows in subsurface porous media. This study examined a simple cyclic time‐dependent displacement rate and its effects on the onset and longer development of VF. It is found that such varying displacement rate can either stabilize or destabilize VF, depending on the cycle period, amplitude, and displacement scenarios. The most important mechanism is that such time‐dependent rate can effectively change the competition between convection (destabilizing effect) and dispersion (stabilizing effect). This is different from the widely used constant injection rate where the flow instability is actually determined by the Peclet number and mobility contrast for a given scenario. This study therefore provided a new aspect to control VF, either enhance or reduce, with low additional costs. It is therefore both scientifically and practically important for a wide range of flows in subsurface porous media. © 2017 American Institute of Chemical Engineers AIChE J, 65: 360–371, 2019

show abstract

Estimation of concentration‐dependent diffusion coefficients of gases in heavy oils/bitumen using experimental pressure‐decay data

Cited by 16 publications

References 27 publications

Diffusion Studies of Glucose and Sucrose in Chitosan Membranes and Beads for Enzymatic Production Processes

Diffusion Studies of Glucose and Sucrose in Chitosan Membranes and Beads for Enzymatic Production Processes

Correlation for the Diffusivity of Gaseous and Liquid Hydrocarbons with Bitumen

Control of viscous fingering and mixing in miscible displacements with time‐dependent rates

Contact Info

Product

Resources

About