Events

Speaker:  Dr. Steven Bryant, Professor and University of Calgary Canada Excellence Research Chair (CERC) at the Department of Chemical and Petroleum Engineering, University of Calgary

Title of Seminar: Stabilizing static and flowing emulsions with nanoparticles

Abstract: Complex fluids change their properties in response to external perturbations, such as pH, temperature or shear rate.  As an important class of complex fluids, classical (surfactant-stabilized) and Pickering (particle-stabilized) emulsions have been widely studied, with the goal of improving emulsion qualities such as rheological properties and emulsion stability.  Microscopic imaging of these emulsions can provide valuable information including emulsion type, droplet size and particle location within Pickering emulsions.  This imaging has typically been limited to static conditions, although all applications employing emulsions require that the emulsion be subject to some type of flow/shear at some time.  During this flow/shear, many emulsions suffer from instability, including widespread coalescence/creaming and/or the accumulation of one component on the channel walls.  Conversely, commingled flow of the fluid phases can generate emulsions under some conditions.  The competition between droplet coalescence and droplet generation is of particular interest for flows through porous media.  Extensive experimentation with nanoparticle-stabilized emulsions flowing through core plugs of sedimentary rocks has shown a wide range of puzzling behavior. 

In this work, we use dynamic confocal microscopy imaging to better understand mechanisms of emulsion stabilization via nanoparticles. Static observations reveal a new mode of synergistic action between nanoparticles and surfactants and development of remarkable interfacial structures.  Flowing observations show strong influence of the wettability of the pore walls and very strong influence of interfacial structures on emulsion rheology.

Biography:   Steven Bryant joined the University of Calgary as the Canada Excellence Research Chair (CERC) in Materials Engineering for Unconventional Oil Reservoirs and Professor in the Department of Chemical and Petroleum Engineering in the Schulich School of Engineering. He is the university’s first CERC and came here after the university was granted a so-called “hunting license” to scour the globe for an energy researcher who would complete an already robust team of heavy oil and oilsands researchers. Steven will lead and co-ordinate nanotechnology and materials science research at the University of Calgary, and the integrated team of researchers from across campus who will aim to drastically change how the oilsands are developed. Before accepting this position, he was at the University of Texas at Austin, as Bank of America Centennial Professor in the Department of Petroleum and Geosystems Engineering, and directed the Geological CO2 Storage Joint Industry Project and the Nanoparticles for Subsurface Engineering Industrial Affiliates Program. Steven pioneered the fields of digital petrophysics and nanoparticles for engineering applications, and has made some of the most significant advances in the past 20 years in porous media modeling, reactive transport theory and CO2 sequestration. Steven has published more than 340 times in books, book chapters, peer-reviewed journals and conference proceedings on applications in production engineering, reservoir engineering and formation evaluation. Over his career, Bryant has led major research initiatives involving industry partnerships and trained over 90 graduate students and postdoctoral fellows who found positions in several of the largest energy companies and national laboratories.