Sheng Dai is an Assistant Professor in the School of Civil and Environmental Engineering at Georgia Institute of Technology in Atlanta, Georgia, USA. Dr. Dai earned his B.S., M.S., and Ph.D. degrees in civil engineering from Tongji University and Georgia Institute of Technology. He was then supported by ORISE fellowship to work at the National Energy Technology Laboratory of U.S. Department of Energy. In August 2015, he returned to Georgia Tech as a faculty in the geosystems engineering group and leads the Subsurface Processes Research Laboratory. He teaches soil behavior, energy geotechnics, and dynamic analyses in geotechnical engineering at Georgia Tech. Dai’s research group explores the scientific foundations of geomaterial behavior at elevated pressure and temperature conditions through wave characterization, imaging techniques, and innovative device development.
What brought you to Georgia Tech?
I spent five years at Georgia Tech to earn my M.S. and Ph.D. degrees. I felt very content during that five years, in a great part due to the inspirational and supportive environment of the geosystems group and the innovative interdisciplinary research environment of the institution. My graduate study at Georgia Tech not only equipped me with the knowledge and skills needed to be an independent researcher but also inspired me to dream the impossible. I appreciate that very much. Also, the professors in the geosystems group at Georgia Tech are exceptionally supportive and encouraging. They are very professional with a healthy blend of humanity and care. Nothing could be better to have them as mentors and colleagues.
Explain some recent energy-related projects of your lab.
My lab is currently funded by several projects on gas hydrate, which is a promising new energy source as well as a risk to global climate. We intend to understand the fundamental physical and geomechanical properties of natural hydrate-bearing sediments, new gas production techniques, and innovative in-situ reservoir characterization/logging tools. We also collaborate with National Energy Technology Laboratory and US Geological Survey to develop the pressure core testing system, which allows us to manipulate, subsample, and test marine sediments with natural gas hydrate that never experienced depressurization.
We also study fundamental geomechanical and hydrological properties of geomaterials undergoing phase change in pores at high pressure and high temperature conditions. We recreate the deep subsurface conditions in the lab and reevaluate the thermo-hydro-chemo-mechanical processes. These will enhance our understanding on the geomaterials behavior during for instance geothermal energy recovery and geological carbon sequestration.
Additionally, we get involved in the NSF funded Engineering Research Center for Bio-mediated and Bio-Inspired Geotechnics (CBBG), in which we collaborate with microbiologists at Georgia Tech to look at the microbial activities at high pressure conditions and their impacts to the geophysical and geochemical properties of natural sediments. This topic has not been well studied due to experimental challenges, yet is of great importance to understand the microbial role in the fate of hydrocarbons and potentials of using microbial activities to enhance energy and resource recovery.
How are geotechnical/geomechanical advances helping us gain better understanding of the relationship between subsurface geology and engineered systems?
The thermo-hydro-chemo-bio-mechanical processes in subsurface are always coupled. Geomechanical behavior affects and also be affected by other properties of geomaterials. Goetechnical advancements have provide designs of secure foundation systems for many energy infrastructure such as nuclear power plants, wind mills, and hydroelectric dams. Enhanced understanding on subsurface geomechanical behavior will play a central role the design, construction, and operation of geothermal energy system, hydrocarbon (gas and petroleum) production wells, reservoir stability, engineered clayey barriers for secure nuclear waste depository, geological carbon sequestration, and so on. The engineered systems also need new construction methods, based on better understanding of subsurface processes, to reduce embodied energy in infrastructures and minimize environmental impacts in view of life-cycle functioning and decommissioning.
What role will geomechanics play in enabling safe, sustainable production of domestic energy resources?Geomechanics is critical to the solution of many resource and sustainability related problems. Geotechnical engineering provides the static and dynamic design of foundations for all energy infrastructure components. Geomechanical problems in hydrocarbon production include sand production, fines migration and clogging, borehole instability, various needs of enhanced oil recovery and production of heavy oil and tar sands, shale instability, fracking, to name a few. The whole safety, security, efficiency, and economics of mining industry is based on adequate site and geomaterials characterization, optimal excavation strategies, and reliable deformation prediction and remediation techniques. Obviously, geomechanics plays an important role in geothermal energy recovery and the design and construction of geothermal systems. In fact, geomechanics is critical not only to reliable energy production but also to massive storage of fossil and renewable energy via underground storage to bridge the gaps between energy demand and energy supply.
If you were not teaching or conducting research, what would you be doing?I would be making string instruments, preferentially classic guitar. I would like to make guitars using new materials with various dynamic characteristics (e.g., mass, springiness, damping, deformation memory, etc.). I would also like to deploy wave characterization techniques to equip the guitars with geophones, optical fiber, and piezo-crystals to monitor the resonance behavior of each part of the guitar, and make corresponding improvements. That will be a fun.