Effect of Near-Wall Turbulence on Selective Removal of Particles From Sand Beds Deposited in Pipelines

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Hossein Zeinali ◽  
Peter Toma ◽  
Ergun Kuru
Keyword(s):  
Fine Particles ◽  
Size Composition ◽  
Selective Removal ◽  
Turbulent Pipe Flow ◽  
Wall Turbulence ◽  
Particle Removal ◽  
Flow Loop ◽  
Near Wall Turbulence ◽  
Near Wall ◽  
Sand Beds

This paper investigates the effect of near-wall turbulence on selective removal of small-size particulate matter from sand beds deposited in pipelines. In an effort to develop effective strategies for in-line fines separation, experimental data on selective particle removal by burst-sweep turbulent structures have been gathered. A 3¾″ (0.095 m) diameter—15 m long flow loop together with a particle image velocimetry (PIV) system has been commissioned and used for observations of turbulent burst activities. The flow loop was also equipped with bottom extractors to allow real time sampling of deposited particles which are then analyzed for determining particle size distribution changes with time. In this work, the alteration of size-composition during turbulent transportation of moving (sand) bed was assumed to be the effect of burst-sweep activity (coherent structures). The frequency of coherent burst structures was measured at various distances from the pipe wall, during the radial dissipation, and results were compared with existing literature. The experimental results indicated that when a bed of particles with 0.1–50 μm size range is exposed to burst-sweep activities during turbulent pipe flow, the concentration of fine particles within the bed increases with time (i.e., coarser particles are preferentially removed).

Effect of Particle Size and Surface Properties on the Sandbed Erosion with Water Flow in a Horizontal Pipe

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1096-1112 ◽  
Author(s):  
Mehmet Meric Hirpa ◽  
Sumanth Kumar Arnipally ◽  
Majid Bizhani ◽  
Ergun Kuru ◽  
Genaro Gelves ◽  
...  
Keyword(s):  
Particle Size ◽  
Critical Velocity ◽  
Wall Turbulence ◽  
Shear Stresses ◽  
Particle Removal ◽  
Fluid Interface ◽  
Turbulence Characteristics ◽  
Bed Erosion ◽  
Near Wall Turbulence ◽  
Near Wall

Summary An experimental study was conducted to investigate the transport of sand particles over the sand bed deposited in a horizontal conduit by using turbulent flow of water. The main objectives were to determine the near-wall turbulence characteristics at the onset of bed erosion (i.e., near-wall velocity profile, Reynolds shear stresses, and axial-turbulent intensity); to determine critical velocity required for particle removal from the bed deposits; and more specifically, to determine how the sand-particle size and surface characteristics would influence the critical velocity required for the onset of bed erosion and the near-wall turbulence characteristics. A large-scale horizontal flow loop equipped with a nonintrusive laser-based particle-image velocimetry (PIV) system has been used for the experiments. The effect of sand-particle surface characteristics (i.e., wettability) on the critical velocity and the near-wall turbulence characteristics were investigated by using treated and untreated industrial sands of four different mesh sizes (i.e., 20/40, 30/50, 40/70, 100). The PIV technique was used to determine instantaneous local velocity distribution near the stationary sandbed fluid interface under subcritical and critical flow conditions. The near-wall velocity distribution measured directly at the sand bed/fluid interface together with the measured frictional pressure-loss values were then used for the evaluation of the Reynolds shear stresses and axial turbulent intensities acting at the bed/fluid interface. The results indicated that critical velocity for the onset of particle removal from sand beds increased with the increasing particle size. When sands with special surface treatment were used, it was observed that the critical velocity required for the onset of the bed erosion was significantly lower than that of required for the untreated sands. The degree of reduction in critical velocity varied between 14 and 40% depending on the particle size. In this study, by conducting experiments under controlled conditions, we provided much-needed fundamental data that can be used for the development of improved solid-transport design criteria and suitable mitigation technologies. In particular, we have shown the proof of concept that the surface-treated sand particles might have great potential for improving the transport efficiency of proppants used for hydraulic-fracturing operations.

scholarly journals Effect of the Particle Size on the Near-Wall Turbulence Characteristics of the Polymer Fluid Flow and the Critical Velocity Required for Particle Removal from the Sand Bed Deposited in Horizontal Wells

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3172
Author(s):  
Mehmet Meric Hirpa ◽  
Sumanth Kumar Arnipally ◽  
Ergun Kuru
Keyword(s):  
Particle Size ◽  
Fluid Flow ◽  
Turbulent Flow ◽  
Critical Velocity ◽  
Wall Turbulence ◽  
Sand Particle ◽  
Particle Removal ◽  
Polymer Fluid ◽  
Near Wall Turbulence ◽  
Near Wall

Water-based polymer drilling fluids are commonly used for drilling long horizontal wells where eliminating the drilling fluid-related formation damage and minimizing the environmental impact of the drilling fluids are the main concerns. An experimental study was conducted to investigate the turbulent flow of a polymer fluid over a stationary sand bed deposited in a horizontal pipeline. The main objectives of the study were to determine the effects of sand particle size on the critical velocity required for the onset of the bed erosion and the near-wall turbulence characteristics of the polymer fluid flow over the sand bed. Industrial sand particles having three different size ranges (20/40, 30/50, 40/70) were used for the experiments. The particle image velocimetry (PIV) technique was used to determine instantaneous local velocity distributions and near-wall turbulence characteristics (such as Reynolds stress, axial and turbulence intensity profiles) of the polymer fluid flow over the stationary sand bed under turbulent flow conditions. The critical velocity for the onset of the particle removal from a stationary sand bed using a polymer fluid flow was affected by the sand particle size. The critical velocity required for the particle removal from the bed deposits did not change monotonously with the changing particle size. When polymer fluids were used for hole cleaning, the particle size effect on the critical velocity varied (i.e., critical velocity increased or decreased) depending on the relative comparison of the sand particle size with respect to the thickness of the viscous sublayer under turbulent flow condition.

Mechanism of control of the near-wall turbulence using a micro-cavity array

2021 ◽  
Vol 33 (7) ◽  
pp. 075114
Author(s):  
S. S. Bhat ◽  
A. Silvestri ◽  
B. S. Cazzolato ◽  
M. Arjomandi
Keyword(s):  
Wall Turbulence ◽  
Micro Cavity ◽  
Near Wall Turbulence ◽  
Cavity Array ◽  
Near Wall

scholarly journals Minimal multi-scale dynamics of near-wall turbulence

2021 ◽  
Vol 913 ◽  
Author(s):  
Patrick Doohan ◽  
Ashley P. Willis ◽  
Yongyun Hwang
Keyword(s):  
Wall Turbulence ◽  
Multi Scale ◽  
Near Wall Turbulence ◽  
Near Wall

Abstract

Nonlinear analysis of near-wall turbulence time series

1996 ◽  
Vol 57 (3-4) ◽  
pp. 235-261 ◽  
Author(s):  
A. Porporato ◽  
L. Ridolfi
Keyword(s):  
Time Series ◽  
Nonlinear Analysis ◽  
Wall Turbulence ◽  
Near Wall Turbulence ◽  
Near Wall
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