Events Calendar

Astani Civil and Environmental Engineering Seminar

Speaker: Dr. Birendra Jha, Viterbi School, Department of Petroleum Engineering

Talk Title: Characterization of Transport in Stress-sensitive Aquifers

Abstract: Push-pull tracer tests are often used in groundwater engineering to characterize properties and processes in aquifers, e.g., using the tracer residence time information to quantify the number and geometry of fractures present in the aquifer, which is important for estimating hydraulic conductivity of the aquifer. Tracer transport through aquifers is typically modeled assuming the medium is rigid. However, many applications exist where the medium is mechanically deforming or evolving at some scale, e.g., due to the presence of fractures, soft rock, or chemical reactions. Characterization of transport in those aquifers requires understanding how geomechanical processes affect transport signals e.g., solute breakthrough time and degree of mixing, and how transport processes affect geomechanical signals e.g., stress changes and fracture activation. We test these hypotheses in a numerical model of push-pull testing in a fractured aquifer for which we develop a multiphysics modeling framework to solve the problem of fluid flow, tracer transport, poroelasticity, and fracture mechanics. We use the model to answer practical questions such as how much change in the tracer breakthrough time and degree of mixing corresponds to a given change in the average volumetric stress during aquifer pumping.



Biography: Birendra Jha is an assistant professor of petroleum engineering at the University of Southern California, where his lab gemlab.usc.edu conducts research in fluid flow and mechanical deformation processes to better forecast the performance and hazards of subsurface engineering operations such CO2 sequestration and groundwater remediation in stress-sensitive rocks. His research has been funded by the US Department of Energy, National Science Foundation, American Chemical Society, and energy companies. Birendra received his masters and PhD from Stanford University and Massachusetts Institute of Technology, respectively.

Location: Michelson Center for Convergent Bioscience (MCB) - 102

Audiences: Everyone Is Invited

Contact: Evangeline Reyes