Analysis of suspension sedimentation in fluids with rheological shear-thinning properties and thixotropic effects

Moreira, Bruno Arantes; Arouca, Fábio de Oliveira; Damasceno, João Jorge Ribeiro

doi:10.1016/j.powtec.2016.12.034

Cited by 33 publications

(37 citation statements)

References 22 publications

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“…However, for Y sufficiently large, we find higher settling efficiency with increasing solid volume fraction, indicated by the increased mean settling velocity. This is similar to what has been observed in experimental studies of settling suspensions in shear-thinning fluids [45]. There, settling particles shear fluid, causing a local decrease in viscosity and thereby allowing nearby particles to settle more easily.…”

Section: Resultssupporting

confidence: 87%

Direct numerical simulation of particle sedimentation in a Bingham fluid

Koblitz¹,

Lovett

Nikiforakis³

2018

Phys. Rev. Fluids

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The settling efficiency, and stability with respect to settling, of a dilute suspension of infinite circular cylinders in a quiescent viscoplastic fluid is examined by means of direct numerical simulations with varying solid volume fraction, φ, and yield number, Y . For Y sufficiently large we find higher settling efficiency for increasing φ, similar to what is found in shear-thinning fluids and opposite to what is found in Newtonian fluids. The critical yield number at which the suspension is held stationary in the carrier fluid is found to increase monotonically with φ, while the transition to settling is found to be diffuse: in the same suspension, particle clusters may settle while more isolated particles remain arrested. In this regime, complex flow features are observed in the sedimenting suspension, including the mobilization of lone particles by nearby sedimentation clusters. Understanding this regime, and the transition to a fully arrested state, is relevant to many industrial and natural problems involving the sedimentation of viscoplastic suspensions under quiescent flow conditions. * A.R. Koblitz acknowledges financial support from the EPSRC Centre for Doctoral Training in Computational Methods for Materials Science under grand EP/L015552/1.; This work was supported by Schlumberger Cambridge Research Limited.; ark44@cam.ac.uk arXiv:1806.04513v1 [physics.flu-dyn]

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Section: Resultssupporting

confidence: 87%

Direct numerical simulation of particle sedimentation in a Bingham fluid

Koblitz¹,

Lovett

Nikiforakis³

2018

Phys. Rev. Fluids

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“…Although some studies have been carried out [10][11][12][13][14][15][16][17] on the behavior of settling particles in shear-thinning fluids, there is lack of information on this phenomenon in drilling fluids, especially in the compression zone.…”

Section: List Of Notationmentioning

confidence: 99%

“…Gamma-ray attenuation measurements is a technique used to obtain indirect volumetric concentration of solids in batch sedimentation tests without interfering in the configuration and stability of the medium. This technique was applied in studies of gravitational sedimentation in Newtonian fluids [18][19][20] and laboratory produced shearthinning fluids [16]. The radioisotope application unit, represented by the flow chart of Figure 1, consisted of a radiation targeting/ detection system coupled to a metal structure.…”

Section: Gamma-ray Attenuation Techniquementioning

confidence: 99%

Study on the stability of a shear-thinning suspension used in oil well drilling

Fagundes

Santos

Damasceno

et al. 2018

Oil & Gas Science and Technology - Rev. IFP Energies nouvel

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In order to avoid solid-liquid gravitational separation of particles in the drilling fluid and cuttings generated in this process, the oil industry has been developing drilling fluids with shear-thinning and thixotropic characteristics. In case of operational stops in the drilling process, the intense sedimentation of these particles can damage the equipment used and the well. In this context, this study simulated an operational stop to obtain information about stability of solids in a paraffin-based suspension with time-dependent shear-thinning behavior, which has already been used in current drilling processes. A long-term test using gamma-ray attenuation technique identified the separation dynamics of a set of micrometric particles belonging to and incorporated into the drilling fluid during operation. This test verified the typical regions of gravitational sedimentation and, through constant concentration curves, indicated that the sedimentation process did not occur at a constant rate. This study also proposed a constitutive equation for pressure on solids.

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“…For this reason, the behavior of particles settling in a fluid has been widely studied over the years in both Newtonian fluids [1][2][3][4][5][6] and non-Newtonian fluids [7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Relationships Between Permeability, Pressure on the Solids, and Porosity for Calcium Carbonate

Moreira¹,

Arouca²,

Damasceno³

2018

Sedimentation Engineering

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This study aims to evaluate the constitutive equations for pressure on the solids and permeability of porous media consisting of calcium carbonates with different degrees of polydispersity. The constitutive relations are intended to assist in the modeling and simulation of sedimentation operations when theory of mixtures of continuum mechanics is used. In this work, a porous media was obtained after the complete sedimentation of aqueous suspensions of calcium carbonate. The gamma-ray attenuation technique was used, which allowed the realization of measurements of the distribution of porosity in the sediment before and after liquid percolation. The experimental results showed a considerable degree of compressibility for calcium carbonates, and significant deviations from the Kozeny-Carman correlation when the carbonates were used to express permeability. Therefore, the use of the incompressibility hypothesis for this solid in equations that model sedimentation may not be a viable consideration. Overall, this study provides relevant information about sedimentation for situations in which the formation of compressible sediments occurs.

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Analysis of suspension sedimentation in fluids with rheological shear-thinning properties and thixotropic effects

Cited by 33 publications

References 22 publications

Direct numerical simulation of particle sedimentation in a Bingham fluid

Direct numerical simulation of particle sedimentation in a Bingham fluid

Study on the stability of a shear-thinning suspension used in oil well drilling

Analysis of Relationships Between Permeability, Pressure on the Solids, and Porosity for Calcium Carbonate

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