Harvey Yarranton
Positions
Professor
Schulich School of Engineering, Department of Chemical and Petroleum Engineering
Contact information
Background
Educational Background
B.S. Chemical Engineering, University of Alberta, 1985
Doctor of Philosophy Chemical Engineering, University of Alberta, 1997
Research
Areas of Research
Heavy oil is challenging to produce because it can have a high viscosity (up to 1 million mPa.s) at standard conditions. In many reservoirs, it's viscosity must be reduced before it can be produced. One method to do so is to inject a solvent to dilute the oil so that it can flow. To design and model these processes, it is necessary to predict the phase behavior and properties of the injected solvent. My group has collected comprehensive datasets for the phase behavior of n-alkane diluted bitumens including saturation pressures, liquid-liquid boundaries, heavy component yields, and phase compositions. We have collected partial datasets for heavy oil with other solvents including multi-component solvents such as condensates. We have also measured the density, viscosity, and thermal conductivity data for these mixtures. We have developed oil characterization methodologies, property correlations, and adapted several phase behavior models based on these datasets.
We are currently investigating the impact of dissolved water on the phase behavior and properties of mixtures of bitumen and n-alkanes.
Partial upgrading (including visbreaking) of bitumen is of current interest in Alberta but data are scarce for the properties of visbroken bitumens. My group is investigating the density, viscosity, and stability versus asphaltene precipitation of visbroken bitumens. We have measured the composition and properties of samples visbroken with in-house reactors. We have adapted our viscosity correlation to predict the product viscosity and updated our regular solution phase behavior model to predict their stability versus asphaltene precipitation.
We are currently investigating combinations of deasphalting and visbreaking in order to find a combination that can reduce the amount of solvent required to dilute bitumen to meet pipeline specifications.
Water-in-crude oil emulsions are dispersions of water in oil. They can be challenging to break but the mechanism by which they are stabilized has been the subject of much speculation. Asphaltenes, the least soluble and most aromatic fraction of crude oil, are believed to be the main culprit. My research group demonstrated that asphaltenes initially adsorb on the interface as a monolayer over a broad range of concentrations. It was not clear how such a thin initial layer could create stable emulsions. We proposed that the stability is conferred by the resistance to compression of the irreversibly adsorbed asphaltene film (the surface area of the emulsified droplets decreases when coalescence occurs leading to interfacial compression). Recently, we demonstrated how salinity affects the asphaltene film properties of these emulsions and linked emulsion stability to the mass of asphaltenes that adsorb at the interface. We constructed an apparatus to investigate the growth of emulsion layers in continuous separations and have shown how solids accumulate in the emulsion (rag) layer and lead to stable emulsions and rag layer growth.
We are currently investigating the impact of the solvent type on the stability versus coalescence of asphaltene and bitumen stabilized emulsions. We are also investigating the variation in the amount of emulsion stabilizers present in bitumen from different oil sands ore deposits.
Solvent-based and solvent-assisted (solvent plus steam) recovery methods are a potential alternative to thermal recovery methods. These recovery methods use less steam than purely thermal methods or no steam at all; and therefore, have lower energy requirements, use less water, and have lower greenhouse gas emissions. In these processes, the solvent diffuses into the oil and decreases its viscosity. One process of interest is the condensing solvent process. In this method, a vaporized solvent with a saturation condition at the reservoir pressure is injected into the reservoir through a horizontal injector placed above a horizontal producer. A solvent vapor chamber is created and the solvent condenses at the vapor/bitumen interface creating a liquid-liquid contact. The bitumen diffuses into the liquid solvent and the mixture of oil and solvent drains to the producer.
The field operation of solvent-based processes is impeded by the absence of a reliable prediction model since the exact mechanisms governing gravity drainage in solvent-based recovery processes have not yet been established. Hence, to predict the performance of condensing solvent processes, a complete and accurate understanding of the mechanisms is necessary. These mechanisms include mass and heat transfer between solvent and bitumen and the gravity drainage of the mixture of bitumen and solvent.
We are currently investigating gravity drainage with a liquid solvent layer over bitumen in a Hele-Shaw cell (a parallel glass plate visual cell with a narrow gap between the plates and packed with glass beads or sand). A layer of solvent over a tilted bitumen surface and the bitumen and solvent production rates are measured as a function of the flow rate, angle of the interface, porosity, permeability, and water saturation. We are developing a model to predict the mass transfer and bitumen recovery rates at the lab scale. The ultimate goal is to use the model to scale lab measurements to the field.
Participation in university strategic initiatives
Courses
| Course number | Course title | Semester |
|---|---|---|
| ENPE 511 LAB 01 B01 | Design For Oil & Gas Eng I | 2021 |
| ENPE 511 LEC 01 01 | Design For Oil & Gas Eng I | 2021 |
| ENPE 531 LAB 01 B01 | Design For Oil & Gas Engg II | 2020 |
Awards
- Departmental Research Excellence Award, 2018
- Faculty of Graduate Studies Great Supervisor Award, 2014
- SSE Graduate Supervision Award, 2014
- SPE Outstanding Service Award, 2010
- ESS Teaching Excellence Award, 2008
- Departmental Research Excellence Award, 2006
- Chemical and Oil and Gas Engineering Professor of the Year, 2003
- Departmental Teaching Excellence Award, 2000
- CFI New Opportunities Award, 1998
- SPE Distinguished Lecturer, Society of Petroleum Engineers. 2020
- SPE Calgary Section Award for Technical Excellence, Society of Petroleum Engineers. 2020
- SPE Regional Distinguised Achievement Award, Society of Petroleum Engineers. 2021
Publications
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