Profile
David S. Nobes is a Professor in the Department of Mechanical Engineering at the University of Alberta and considers flow phenomena from a macro/micro, experimental-fluid-mechanical point of view. His research areas include combustion, turbulent jets, oil sands separation processes, two-phase flows, active control of fluid flows, blood flow in the heart and energy conversion using Stirling engines. To undertake this research, his group has custom developed unique optical measurement systems that have been deployed over a wide range of scales. These advanced laser/image/optical techniques have been funded by a CFI, NESRC and through industrial collaboration. He has supervised more than 50 MSc and PhD students and published more than 200 peer-reviewed publications.
Contact infromation is as follows:
------------------------------------------------------------------- David S. Nobes PhD, BE(Mech), P.Eng Professor Department of Mechanical Engineering University of Alberta Edmonton, Alberta CANADA, T6G 1H9 ph : (780) 492 7031 email: david.nobes@ualberta.ca Web : ualberta.ca/~dnobes/ ------------------------------------------------------------------- FES Funded ProjectsOutputs
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Non-Traditional Drive Mechanism Designs for the Improvement of Heat Transfer in Low Temperature Differential Stirling EnginesT05-P03 | Publication | 2018-09-19 | Michael Nicol-Seto, Jason Michaud, Steven Middleton, David S. Nobes | Evaluation Of A Low Temperature Stirling Engine Using A Discontinuous Thermodynamic CycleT05-P03 | Activity | 2019-04-14 | Michael Nicol-Seto, David S. Nobes | Investigation of a Drive Mechanism Modification to Increase Thermodynamic Power of a Low Temperature Differential Gamma Type Stirling EngineT05-P03 | Publication | 2021-09-20 | Michael Nicol-Seto | Early Development of a 100 Watt Low Temperature Difference Stirling EngineT05-P03 | Publication | 2020-06-27 | Matthias Lottmann, Zachary Christopher De Rouyan, Linda Hasanovich, Steven Middleton, Michael Nicol-Seto, Connor Speer, David S. Nobes | Performance of a Modified Drive Mechanism on a Low Temperature Differential Stirling EngineT05-P03 | Publication | 2020-06-27 | Michael Nicol-Seto, David S. Nobes | Investigations into the effect of heat exchanger volume and geometry on low-temperature Stirling engine performanceT05-P03 | Publication | 2020-06-27 | Linda Hasanovich, David S. Nobes | Effect of Heat Exchanger and Engine Geometry on Power Output of a Low Temperature Difference Stirling EngineT05-P03 | Publication | 2023-03-26 | Linda Hasanovich, David S. Nobes | Effect of Heat Exchanger Volume and Geometry on Power Output of a Low Temperature Difference Stirling EngineT05-P03 | Publication | 2022-09-20 | Linda Hasanovich | An Experimental and Modeling Study of Carbon Dioxide/Bitumen and C4/Bitumen Phase Behavior at Elevated Temperatures Using Cold Lake BitumenThe coinjection of carbon dioxide (CO2) or light hydrocarbons with steam in the steam-assisted-gravity-drainage (SAGD) process
might enhance bitumen mobility and reduce the steam/oil ratio (SOR). Understanding and modeling the phase behavior of solvent/
bitumen systems are essential for the development of in-situ processes for bitumen recovery. In this paper, an experimental and
modeling study is undertaken to characterize the phase behavior of bitumen/CO2 and bitumen/C4 systems. Produced and dewatered oil
from the Cenovus Osprey Pilot is used for the experiments. The Osprey Pilot produces oil from the Clearwater Formation. Constantcomposition-
expansion (CCE) experiments are conducted for characterizing Clearwater bitumen, CO2/bitumen mixture, and C4/bitumen
mixture. The Peng and Robinson (1978) equation of state (EOS) (PR-EOS) is calibrated using the measured data and is used for pressure/
volume/temperature (PVT) modeling. Multiphase equilibrium calculations are performed to predict the solubility of CO2 and C4 in the
temperature range of 393.2 to 453.2 K. The potential of asphaltene precipitation for CO2/bitumen and C4/bitumen mixtures is also
investigated using three screening criteria.
According to the CCE tests and multiphase equilibrium calculations, C4 has much higher solubility in bitumen than does CO2 at operating
pressure of 3997.9 kPa and temperature between 393.2 and 453.2 K. (393.2 K | Publication | 2019-04-18 | | An Experimental and Modeling Study on Interactions of Cold Lake Bitumen with CO2, C3, and C4 at High TemperaturesCoinjecting CO2 and light hydrocarbons with steam into oil sand reservoirs can improve the efficiency of the
SAGD (steam assisted gravity drainage) process by reducing the steam oil ratio (SOR). The effects of these solvents on bitumen
recovery enhancement depend on reservoir properties and operating conditions. To investigate the effects of solvents on
bitumen viscosity in a solvent aided process, phase behaviors and viscosities of CO2−, C3−, and C4−bitumen systems were
measured and modeled at high temperatures. Using the calibrated Peng−Robinson equation of state (PR-EOS), the solubilities
of solvents in the Clearwater bitumen sample from the Cold Lake region were predicted. High-pressure and high-temperature
equipment using an electromagnetic-based viscometer was customized to measure the viscosities of CO2−, C3−, and C4−
bitumen mixtures. The measured viscosity data were used to calibrate a nonlinear viscosity model which was used to predict
liquid phase viscosity as a function of solvent solubility and temperature. The effects of solvent dissolution on bitumen viscosity
were investigated using PR-EOS and the calibrated viscosity model. The results show that dissolving CO2, C3, and C4 in
bitumen decreases its viscosity. This viscosity reduction is lowest and highest in the case of CO2 and C4 dissolution,
respectively. The effect of solvent dissolution on viscosity reduction is more pronounced at lower temperatures. EOS
predictions and viscosity measurements indicate that increasing concentration of CO2, C3, and C4 above a certain threshold has
a limited effect on reducing bitumen viscosity. At threshold solvent concentrations, bitumen viscosity can be reduced by 1.7, 5.6,
and 15.2 times using CO2, C3, and C4, respectively, at 120 °C. Solubility and viscosity data suggest that C4 has the potential to
be used in hot-solvent recovery methods in shallow and deep oil sand reservoirs. C3 may be a more effective solvent in deeper
reservoirs which allow higher operating pressures. The modified viscosity model showed better performance than the Lobe and
Shu correlations and logarithmic mixing rule. This model improves existing correlations for predicting viscosities of light
solvent−bitumen mixtures since it requires less input data and does not require density data.T07-P05 University of Alberta | Publication | 2019-04-18 | | Visualizing Oil Recovery Mechanisms During Natural Gas Huff-n-Puff Experiments on Ultra-tight Core PlugsLow oil recovery factors and rapid decline rates are key challenges in developing shale and tight oil formations. Despite encouraging gas Huff-n-Puff (HnP) field pilot results, the oil-recovery mechanisms are still not well understood. This paper investigates the oil-recovery mechanisms during a natural gas (C1 and a mixture of C1/C2 with the molar ratio of 70/30) HnP process on ultralow-permeability Montney plugs. This study comprises of two sets of tests that are conducted under core-plug and bulk-phase conditions. To investigate oil-recovery mechanisms from an oil-saturated core plug, we used a custom-designed visualization cell to visualize the interactions at the surface of the plug during natural-gas injection (huff), soaking, and pressure-depletion (puff) processes under reservoir conditions of 2,000 psig and 50oC. This experimental setup simulates a 1-D gas diffusion process which is believed to occur at the fracture faces during the gas HnP process. To complement the core-plug tests, we conducted bulk-phase tests including (1) vanishing interfacial tension (VIT) to estimate minimum miscibility pressure (MMP), (2) constant composition expansion (CCE), and (3) visualization tests to study the phase behavior of gas-oil systems.
We observed four main oil-recovery mechanisms including vaporizing/condensing-gas drive, oil swelling, molecular diffusion, and solution-gas drive, from the core-plug and bulk-phase tests. In that, the major mechanisms are the oil swelling, molecular diffusion, and solution-gas drive during the injection, soaking and depressurization phases of the core-soaking tests, respectively. Oil swelling in C1 and C1/C2 tests appears to be pronounced during gas-injection and soaking phases. During the depressurization phase, the expansion of diffused gas leads to a significant flow of oil comingled with gas, observed at the surface of the plug. According to the MMP measurements, increasing mol% of C2 in the injection gas (0 to 29.7%) reduces MMP of the gas-oil system from 4,350 psig to 2,726 psig. The developed miscibility conditions by enrichment of injection gas enhance the diffusivity of gas into the oil phase and the plug during the soaking period. Vaporization of oil components into the gas phase and condensation of C1/C2 into the oil phase in the bulk-phase visualization tests lead to higher oil swelling in the C1/C2 test compared to pure C1 test. The results of CCE and bulk-phase visualization tests suggest that the addition of C2 to the injection gas increases oil swelling which may explain higher oil recovery by the C1/C2 mixture compared with pure C1 in the core-soaking tests.
T07-P05 University of Alberta | Publication | 2020-06-10 | | Measuring diffusion coefficients of gaseous propane in heavy oil at elevated temperaturesMolecular diffusion is an important phenomenon for solvent transport during vapor extraction and hot solvent injection into heavy oil reservoirs. Therefore, determining solvent diffusion into heavy oil is important for predicting oil recovery. We conduct soaking tests at different temperatures ranging from 80 to 130 °C to estimate diffusion coefficient of propane (C3H8) into heavy oil samples taken from Clearwater Formation in the Western Canadian Sedimentary Basin. The tests are conducted at the maximum initial pressure of 1900 kPa to keep C3 in vapor phase within the tests’ temperature range. Pressure decline during the soaking process is analyzed to estimate diffusion coefficients and solubility of propane in the oil at equilibrium conditions. The final viscosity of the mixture is also calculated by using the available correlations. The results show that diffusion of propane in heavy oil undergoes three different stages: early region, transition region, and late-time region. The maximum diffusion coefficient is observed at the end of transition region. Solubility of C3 in the oil increases with decreasing temperature. The results also reveal that during the three regions, solubility and diffusion coefficients of C3 into the oil strongly depend on temperature.T07-P05 University of Alberta | Publication | 2020-02-03 | | Quantifying Oil-Recovery Mechanisms during Natural-Gas Huff ‘n’ Puff Experiments on Ultratight Core PlugsDespite promising natural gas huff ‘n’ puff (HnP) field-pilot results, the dominant oil-recovery mechanisms during this process are poorly understood. We conduct systematic natural-gas (C1 and a mixture of C1/C2 with the molar ratio of 70/30) HnP experiments on an ultratight core plug collected from the Montney tight-oil Formation, under reservoir conditions (P = 137.9 bar and T = 50oC). We used a custom-designed visualization cell to experimentally evaluate mechanisms controlling (i) gas transport into the plug during injection and soaking phases, and (ii) oil recovery during the whole process. The tests also allow us to investigate effects of gas composition and initial differential pressure between injected gas and the plug (∆Pi = Pg−Po) on the gas-transport and oil-recovery mechanisms. Moreover, we performed a Péclet number (NPe) analysis to quantify the contribution of each transport mechanism during the soaking period.
We found that advective-dominated transport is the mechanism responsible for the transport of gas into the plug at early times of the soaking period (NPe = 1.58 to 3.03). When the soaking progresses, NPe ranges from 0.26 to 0.62, indicating the dominance of molecular diffusion. The advective flow caused by ∆Pi during gas injection and soaking leads to improved gas transport into the plug. Total system compressibility, oil swelling, and vaporization of oil components into the gas phase are the recovery mechanisms observed during gas injection and soaking, while gas expansion is the main mechanism during depressurization phase. Overall, gas expansion is the dominant mechanism, followed by total system compressibility, oil swelling, and vaporization. During the ‘puff’ period, the expansion and flow of diffused gas drag the oil along its flowpaths, resulting in a significant flow of oil and gas observed on the surface of the plug. The enrichment of injected gas by 30 mol% C2 enhances the transport of gas into the plug and increases oil recovery compared to pure C1 cases.T07-P05 University of Alberta | Publication | 2020-10-05 | Son Thai Tran, Mahmood Reza Yassin, Sara Eghbali, Mohammad Hossein Doranehgard, Dehghanpour, H. | Studying Phase Behavior of Oil-Natural Gas Systems for Designing Gas Injection Operations: A Montney Case StudyAdvances in horizontal drilling and multistage hydraulic fracturing have unlocked tight oil formations, such as Montney in Western Canadian Sedimentary Basin. However, the average oil recovery factor after primary production is 5-10 % of the original oil in place. The aim of this study is to investigate phase behavior and estimate minimum miscibility pressure (MMP) of Montney oil-natural gas systems. The gas samples used in this study are methane (C1) and mixtures of methane/ethane (C1/C2).
To achieve these objectives, we first measure the MMP of the oil-gas system using vanishing interfacial tension (VIT) technique. Second, we perform constant composition expansion (CCE) tests to study the phase behavior of the oil-gas systems using a pressure-volume-temperature cell. Finally, we use the measured CCE data to calibrate Peng-Robinson equation of state (EOS) and estimate MMPs for the oil-gas systems using ternary diagrams.
The results suggest that mechanism for developing miscibility conditions in the system of oil-C1 is vaporizing gas drive, while it is a condensing gas drive for the oil-C1/C2 system. According to the results of VIT tests, adding and increasing C2 mol% in the gas mixtures lead to a significant reduction of MMP of the oil-gas mixture (from 4366 psi for oil-C1 to 1467 psi for oil-C1/C2 with 71.3 mol% C2). The addition and increase of C2 mol% in the gas mixtures enhance oil swelling (a maximum swelling factor of 1.76 for oil-C2 mixture) and reduce MMP of the oil-gas system. Reasonable PR-EOS models are developed from the CCE data and shown thermodynamic reliability to predict fluid phase behavior within the reservoir. The predicted MMPs by plotting two-phase equilibrium data on ternary diagrams appear to be in good agreement with the measured ones. The MMP of the oil-C1/C2 systems can be achieved by either increasing injection pressure or the mole fraction of C2.
T07-P05 University of Alberta | Publication | 2019-11-18 | | Quantifying Oil-Recovery Mechanisms during Natural-Gas Huff ‘n’ Puff Experiments on Ultratight Core PlugsDespite promising natural gas huff ‘n’ puff (HnP) field-pilot results, the dominant recovery mechanisms during this process are poorly understood. We conduct systematic natural-gas (C1, C1/C2 - 70/30 mol%) HnP experiments on an ultratight Montney core plug under reservoir conditions. We used a custom-designed visualization cell to evaluate mechanisms controlling (i) gas transport into the plug, and (ii) oil recovery during the whole process. We also perform a Péclet number (NPe) analysis to quantify gas-transport mechanisms during the soaking period.
We found that advective-dominated transport is the mechanism responsible for the transport of gas into the plug at early times of the soaking period (NPe = 1.58 to 3.03), while molecular diffusion dominates at the late times (NPe = 0.26 to 0.62). From the four studied recovery mechanisms, gas expansion is the dominant one, followed by total system compressibility, oil swelling, and vaporization. The enrichment of injected gas by C2 enhances the transport of gas into the plug and increases oil recovery.T07-P05 University of Alberta | Activity | 2020-11-24 | Son Thai Tran, Mahmood Reza Yassin, Mohammad Hossein Doranehgard, Sara Eghbali, Dehghanpour, H. | A numerical study on compositional modeling of two-phase fluid flow and heat transfer in vertical wells.Geothermal energy is a sustainable and renewable source that can be extracted by circulating a single- or two-phase fluid through a geothermal well system. Two-phase flow and heat transfer models are required for predicting pressure and temperature profiles in oil, gas, and geothermal wells. We model fluid flow, thermodynamics and heat transfer in an idealised vertical well for single-(i.e., water) and two-phase fluid mixtures (CO2-, and air-water) under a bubbly flow regime. First, we calibrated a Peng-Robinson Equation of State (PR-EOS) for CO2-, and air-water systems. Second, we solved continuity, energy and momentum equations and modelled transient conductive heat transfer through the well.. Third, we investigated the effects of mass flow rate, transient heat transfer, single- and two-phase fluid on the extracted power, temperature, and pressure profiles of the deep well bore heat exchanger. The results show that the temperature of the hot fluid decreases as it flows to the surface both in the case of adiabatic flow and in cases with heat loss. The mass flow rate controls the fluid temperature drop during its ascent to the surface (∆T of 11.2 °C and 87.8 °C at mass flow rates of 7 kg/s and 0.02 kg/s, respectively). The production pressure of a gas-liquid phase system is higher than that of a system with single liquid phase at the same injection pressure, temperature, and mass flow rate. Increasing mass flow rate up to a threshold value leads to an increase in the production pressure. Above the threshold mass flow rate (i.e., 7 kg/s in this study), the production pressure reduces because of the significant increase in the frictional pressure drop. Production temperature, production pressure, and total power increases over time due to the local heating around the production well and reduction of the heat loss. T05-P02, T05-P03, T05-P04 | Publication | 2021-05-12 | Sara Eghbali, Jonathan C. Banks, David S. Nobes | Validation and Testing of a Numerical Model for the Design and Up-Scaling of Low Temperature Difference Stirling EnginesT05-P03 | Publication | 2022-09-20 | Matthias Lottmann | Application of Simultaneous Time-Resolved 3-D PTV and Two-colour LIF in Studying Rayleigh-Benard T05-P03 | Publication | 2021-08-01 | Sina Kashanj, David S. Nobes | Investigation Into The Onset Of Turbulent Rayleigh-Benard Convection Using Time-Resolved 2-D Particle Image VelocimetryT05-P03 | Publication | 2020-06-27 | Sina Kashanj, David S. Nobes | Application of 4D two-colour LIF to explore the temperature field of laterally confined turbulent Rayleigh–Bénard convection.T05-P03 | Publication | 2023-01-26 | Sina Kashanj, David S. Nobes | Role of Large-Scale Circulating Structures in Mixed Convection of Poiseuille-Rayleigh-Benard ConvectionT05-P03 | Publication | 2023-03-26 | Sina Kashanj, David S. Nobes | Calculation Of The Nusselt Number From Temperature And Velocity Data Obtained From Enhanced 3D Two-Colour LIF And 3D PTV In A Rayleigh-Benard Convection CellT05-P03 | Publication | 2023-07-11 | Sina Kashanj, "Yeganeh Saffar", "Reza Sabbagh", David S. Nobes | Effect of Scaling Up Low Temperature Differential Stirling Engines, 18th ISEC International Stirling Engine Conference, Tainan, Taiwan, Sept 19-21, 2018 C5. Nicol-Seto, M., Michaud, J., Middleton, S., and Nobes, D.S. (2018) Non-Traditional Drive MechanismT05-P03 | Publication | 2018-09-19 | Calynn Stumpf, Alexander Hunt, David S. Nobes | Dynamic Modelling of Low Temperature Stirling EnginesT05-P03 | Publication | 2018-09-19 | Steven Middleton, David S. Nobes | Performance of ST05G-CNC Stirling Engine Modified for Operation with Reduced Source TemperatureT05-P03 | Publication | 2018-09-19 | Connor Speer, David Miller, David S. Nobes | Modular one-dimensional simulation tool for oscillating flow and thermal networks in Stirling enginesT05-P03 | Activity | 2019-04-14 | Steven Middleton, David S. Nobes | Effect of aspect ratio on pressure loss and characteristics of low Reynolds number flow through narrow slotsT06-P06 University of Alberta | Publication | 2017-01-01 | Yishak Yusuf, Baldygin, A., Reza Sabbagh, Michael Leitch, Prashant R Waghmare, David S. Nobes | VISUALIZATION OF AN ELECTRO ELECTROKINETIC DRIVEN FLOW THROUGH MINI-CHANNELS IN SAGD WELLST06-P06 | Publication | 2017-01-01 | Shadi Ansari, Reza Sabbagh, Faezeh Rasimarzabadi, Michael Leitch, Prashant R Waghmare, David S. Nobes | PROCEEDINGS FULL PAPER TEMPLATE TITLE: VISUALIZATION OF AN ELECTRO ELECTROKINETIC DRIVEN FLOW THROUGH MINI-CHANNELS IN SAGD WELLST06-P06 | Publication | 2017-01-01 | Shadi Ansari, Reza Sabbagh, Faezeh Rasimarzabadi, Michael Leitch, Prashant R Waghmare, David S. Nobes | Approximations for use in cycling thermodynamic systems: Applications for Stirling enginesT05-P03 | Publication | 2020-06-27 | Steven Middleton, David S. Nobes | Preliminary Design of a Hollow Displacer for a Low Temperature Difference Stirling EngineT05-P03 | Publication | 2020-06-27 | Zachary Christopher De Rouyan, Connor Speer, David S. Nobes | Measurement of the flow behavior index of Newtonian and shear-thinning fluids via analysis of the flow velocity characteristics in a mini-channelT06-P06 | Publication | 2020-10-01 | Shadi Ansari, Md Ashker Ibney Rashid, Prashant R Waghmare, David S. Nobes | Application of a Combinatorial Vortex Detection Algorithm on 2 Component 2 Dimensional Particle Image Velocimetry Data to Characterize the Wake of an Oscillating WingT14-P05 University of Alberta | Publication | 2024-01-01 | Mathew Bussière, Guilherme M Bessa, Koch, C., David S. Nobes |
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