MEASUREMENT OF CARRIER FLUID VISCOSITIES OF OIL SAND SLURRIES

• Author / Creator

  Khan, Ghassan I

• This study investigates the factors that contribute to the viscosity of the carrier fluid in oil sandslurries. The carrier fluid is defined as the fine particles and process water in a slurry. Thecarrier fluid viscosity is a crucial parameter in industry and is needed to accurately designpipelines and size vessels. In a pipeline, the slurry must be pumped at a velocity higher thanthe deposition velocity, which is a function of the carrier fluid viscosity. Failure to do so causesparticle deposition and plugging of pipelines leading to shutdowns. The carrier fluid viscositycan also play a crucial role in the performance of separation vessels by hindering the flotation ofbitumen during extraction. The goal of this project is to establish a correlation that can be used tocalculate carrier fluid viscosities and minimize the need for the expensive and time-consumingviscosity measurements. The correlations that currently exist only account for overall fine solidsconcentrations to predict viscosities. However, the results of this study prove the contributing effectof clay activity and water chemistry factors on the viscosity of the carrier fluid. Therefore, it isnecessary to account for such factors in order to accurately calculate viscosity. This study expandsprevious work to include clay activity and water chemistry when predicting viscosities. The typesof clays present in a slurry can vary drastically based on the ore. The presence of highly active clayscan cause increased ion exchange which leads to stronger aggregation and an increase in viscosityvalues. The copper-triethylenetetramine (Cu-Trien) method is used to calculate the activity levelsof clays present. The effect of water chemistry on viscosity is also considered. Process water canvary greatly in terms of pH and dissolved ion concentrations. Water chemistry has been shown toaffect the surface charge of clay particles and in turn the aggregation tendencies of the particles.Ion chromatography is used to determine water chemistry of the samples. Clay activity and waterchemistry are incorporated with fine solids concentration in this study, to develop a model topredict carrier fluid viscosities with a high level of accuracy. This study also shows differencesin viscosities measured by concentric cylinder (CCV) and double gap geometries. The CCV isshown to provide consistently higher viscosities than the double gap geometry for carrier fluidsamples. This may be related to the effect of geometry on the equilibrium state of aggregation of the clay flocs. The double gap viscometer measurements required the use of manufacturer-suppliedconversion factors for shear stress and shear rate which are appropriate only for Newtonian fluidsand so their applicability to these carrier fluids, which exhibited small yield stresses, may belimited. Consequently, the discrepancies between measurements made in different geometriesrequire further investigation. Also, while the results of this study prove the potential for accurateviscosity predictions using CEC and water chemistry, further work is required prior to industrialapplication. Specifically, additional work must be carried out in the future with samples fromdifferent ores of varying clay activity to confirm the relationships found in this study. A widearray of CEC and water chemistry analyses should be conducted and correlated to carrier fluidviscosities to expand this work before it can be applied in industrial settings. The use of opticaltechniques in the future is also recommended to observe particle interactions directly in-situ andquantify the effects on viscosity.

• Subjects / Keywords

  • Hydrotransport
  • Carrier Fluid
  • Clay Activity
  • Viscosity

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-50eb-m286

• License

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