Ingrid Tomac, PhD | UCSD, Department of Structural Engineering
TITLEMicromechanics of dense-phase particle-fluid slurries in the context of proppant flow and transport
ABSTRACTProppant is small material such as 40/70 or 100 mesh sand which is placed in hydraulic fractures of geothermal or hydrocarbon reservoirs. The main role of proppant is to keep open, or prop, newly formed fractures in rock mass for enhancing hydrocarbons or geothermal fluid flow during reservoir exploitation by keeping fractures open and resist formation stress. However, attempts of transporting proppant deep in rock fractures often fails which reduces production and efficiency of hydraulic fracturing jobs. Therefore, there is a need to better understand parameters which affect proppant flow and transport in fractures. This research uses micromechanics to understand interaction of fluid and particles on a single particle scale using experimental, theoretical and numerical methods. Resolved and unresolved Discrete Element Method coupled with computational fluid dynamics is used along with small and intermediate scale experiments to better understand influence of various parameters on slurry flow and transport in a fracture. Smooth and rough fracture walls are considered, as well as, different fracture apertures, particle concentrations, particle sizes and fracturing fluids. Results are focused on developing novel theories for describing dense-phase slurry flow and transport, with emphasis on particle agglomerations and clustering.
BIOI am an Assistant Professor of geomechanics and geotechnical engineering at the Department of Structural Engineering, University of California San Diego. My research interests revolve around soil and rock mechanics, hydraulic fracturing, georeservoirs and carbon dioxide sequestration. I wish to dedicate my research efforts towards creating a better world through exploration and development of civil engineering infrastructure for supporting renewable and sustainable energy resources.
In my research, I use micromechanics, micro-scale imaging videography, fundamental theories, and numerical simulations involving coupling between the Discrete Element Method and computational fluid dynamics (DEM-CFD) to better understand coupled processes in geomechanics at the relevant constituent scale. Current research:
- micromechanics and rheology of dense particulate systems, particle jamming and agglomerations in fractures;
- hydro-thermo-mechanical coupled processes in rock and fundamentals of inelastic rock fracturing;
- hydraulic fracturing and proppant flow and transport in georeservoirs;
- CO2 storage in rock mass;
- mechanics and fracture of ice with impurities;
- hydrophobic soils micromechanics in mud-flows.
Prior to joining academia, I was involved in geotechnical engineering practice in Europe and USA. Through my 10 years consultancy experience, I become an expert in deep excavation design in urban areas, design of retaining walls, soil nailing, soil improvement techniques, landslide remediation and shallow and deep foundation engineering.