Studies of the effect of tracer activity on time-averaged positron emission particle tracking measurements on tumbling mills at PEPT Cape Town

Volkwyn, Trevor; Buffler, Andy; Govender, I.; Franzidis, J.-P.; Morrison, Angus J.; Odo, Ayodele E.; Meulen, Nicholas P. van der; Vermeulen, C.

doi:10.1016/j.mineng.2010.08.020

Cited by 35 publications

(14 citation statements)

References 10 publications

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“…A velocity field might be inferred from careful evaluation of flow rates and relative intensities as a function of time, although determining the velocity field from the discrete-time position densities did not yield unique solutions. Alternatively, the research on this methodology will continue by extending the experiments to include positron emission particle tracking (PEPT) (Hawkesworth et al 1991;Parker et al 1993;Volkwyn et al 2011). A tracer particle of ~100 microns in diameter will be labeled with 18 F-FDG and tracked (Bickell et al 2012) as is migrates down the fracture.…”

Section: Discussionmentioning

confidence: 99%

Dynamic 3D Imaging of Fluid Mobility in Natural Fractures Using High-resolution Positron Emission Tomography

et al. 2014

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Positron emission tomography (PET) continues to have wide-ranging medical application and is based on the detection of gamma radiation emitted from the decay of certain types of radionuclides. Modern PET scanners produce three-dimensional (3D) images of the radiation source, in discrete time steps, using tomography analysis. This paper presents an application of PET for studying fluid mobility in pressurized low-permeability rocks in the presence of natural fractures. This technique uses a high-resolution PET scanner and image reconstruction based on filtered back-projection. Traditional techniques have been limited to pressure measurement of fracture conductivity and effective permeability, but little is understood about the dynamic flow and velocity profiles within the fracture.The objective of this work was to investigate if it is possible to measure the dynamic (e.g., time-lapse and continuous) distribution of the fluid flow as a function of the overburden stress. PET imaging was applied to the flow of a brine solution, which was tagged with 18 F-fluorodeoxyglucose (FDG) positron emitting radionuclide, through nonfractured sandstone and naturally fractured shale cores. A special composite container was manufactured to sustain high-pressure conditions and minimize the absorption of emitted gamma rays. The experimental apparatus is described, and it is demonstrated that the 3D images obtained with a grid resolution of 2 × 2 × 2 mm 3 allow clear determination of the fluid flow rate through the core as a function of overburden pressure and time. PET images are direct observations of the radiation source and allow an unambiguous determination of the fluid distribution in the core. The results of this research can be used to validate the numerical modeling of fluid flow through fractured rock matrices, to enable more accurate estimates on the directionality of fractures from the fluid distribution as a function of time, and to obtain more quantitatively sound estimates of fracture connectivity.

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Section: Discussionmentioning

confidence: 99%

Dynamic 3D Imaging of Fluid Mobility in Natural Fractures Using High-resolution Positron Emission Tomography

et al. 2014

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“…Alternatively, the research on this methodology will continue by extending the experiments to include PEPT (Hawkesworth et al 1991;Parker et al 1993;Volkwyn et al 2011). A velocity field might be inferred from careful evaluation of flow rates and relative intensities as a function of time, although determining the velocity field from the discrete-time position densities did not yield unique solutions.…”

Section: Discussionmentioning

confidence: 99%

Dynamic Positron Emission Tomography: Application to Imaging Fluid Mobility in Fractured Cores

et al. 2013

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Positron emission tomography (PET) continues to have wide-ranging medical application and is based on the detection of gamma radiation emitted from the decay of certain types of radionuclides. Modern PET scanners produce 3D images of the radiation source, in discrete time steps, using tomography analysis. This paper presents an application of PET for studying fluid mobility in pressurized low-permeability rocks in the presence of natural fractures. This technique uses a high-resolution PET scanner and image reconstruction based on filtered back-projection. Traditional techniques have been limited to pressure measurement of fracture conductivity and effective permeability, but little is understood about the dynamic flow and velocity profiles within the fracture.The objective of this work was to determine if it is possible to measure the dynamic (e.g., time-lapse and continuous) distribution of fluid flow as a function of the overburden stress. PET imaging was applied to the flow of brine solution, which was tagged with 18 F-fluorodeoxyglucose (FDG) positron emitting radionuclide, through nonfractured sandstone and naturally fractured shale cores. A special composite container was manufactured to sustain high-pressure conditions and minimize the absorption of emitted gamma rays. The experimental apparatus is described, and it is demonstrated that 3D images obtained with a grid resolution of 2 × 2 × 2 mm 3 allow clear determination of the fluid flow rate through the core as a function of overburden pressure and time. PET images are direct observations of the radiation source and allow an unambiguous determination of the fluid distribution in the core. The results of this research can be used to validate the numerical modeling of fluid flow through fractured rock matrices, to enable more accurate estimates on the directionality of fractures from the fluid distribution as a function of time, and to obtain more quantitatively sound estimates of fracture connectivity.

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“…In this paper, a method is detailed through which the N js may instead be determined using positron emission particle tracking (PEPT), a technique which employs highly penetrating gamma radiation to image the 3D motion of particles even within the interior of dense, optically opaque systems. In addition to potentially offering a more rigorous and unambiguous measurement of N js (the method presented being fully algorithmic as opposed to relying on human interpretation), PEPT's ability to probe opaque systems, objects, and fluids means that such measurements can be performed in real process equipment, and with real industrial fluids and particles [7][8][9][10][11][12].…”

Section: Measuring Solids Suspension and Homogeneity In Stirred-tank mentioning

confidence: 99%

Positron Emission Particle Tracking for Liquid‐Solid Mixing in Stirred Tanks

et al. 2020

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Mixing in stirred tanks is vital to a wide range of industrial processes, typically requiring solids to be fully suspended and evenly distributed. The quality of suspension and mixing is typically measured visually. Such measurements are thus subject to human interpretation and can only feasibly be conducted in transparent systems – an uncommon condition in industrial systems. Visual measurements of homogeneity must also infer full 3D distributions of particles solely from the observation of a limited section thereof. This work details methods by which a system's homogeneity and state of suspension may be measured and quantified with no human interpretation, which can extract information from opaque systems and consider full 3D data acquired throughout the interior of a given system.

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Studies of the effect of tracer activity on time-averaged positron emission particle tracking measurements on tumbling mills at PEPT Cape Town

Cited by 35 publications

References 10 publications

Dynamic 3D Imaging of Fluid Mobility in Natural Fractures Using High-resolution Positron Emission Tomography

Dynamic 3D Imaging of Fluid Mobility in Natural Fractures Using High-resolution Positron Emission Tomography

Dynamic Positron Emission Tomography: Application to Imaging Fluid Mobility in Fractured Cores

Positron Emission Particle Tracking for Liquid‐Solid Mixing in Stirred Tanks

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