I am an Assistant Professor of Petroleum Engineering at The University of Tulsa, where I lead the Fluid and Fracture Dynamics Laboratory.
I build transparent experiments that make hidden subsurface dynamics visible—from a fracture racing ahead of its fluid to trapped oil rearranging one pore at a time.
Our group asks how fluid properties, interfaces, confinement, and heterogeneity govern fracture growth and transport. Current directions include hydraulic fracturing, proppant transport, non-Newtonian flow, critical mineral recovery, geothermal systems, and geological carbon storage.
Prospective students: The lab is recruiting one fully funded Ph.D. student and one fully funded M.S.E. student for Fall 2027. Position details.
Yujing Du, Thomas Cochard, Ilya Svetlizky, Congcong Yuan, Yiqiao Song, Lizhi Xiao, and David A. Weitz
Physical Review Research, 2026
paper / data / research note
Direct visualization separates the fracture front from the fluid front and reveals how polymer properties alter near-tip flow and fluid lag.
Hang Yang, Shuming Kang, Yujing Du, David A. Weitz, and Joost J. Vlassak
Proceedings of the National Academy of Sciences, 2026
Fast deformation localizes viscous dissipation near the crack tip, lowering dynamic fracture toughness and enabling unconventional branching at near shear-wave speeds.
Lucas Mejia, Yujing Du, and Matthew T. Balhoff
SPE Journal, 2023
Direct visualization shows that oil banks can form even at strongly unfavorable viscosity ratios while surfactant-bearing injectant flows within and ahead of the bank.
Song-Chao Qi et al., including Yujing Du
Petroleum Science, 2023
CT measurements reveal an early super-diffusive and late sub-diffusive regime, implying an optimum soaking time rather than indefinite recovery gains.
Yujing Du et al.
Journal of Colloid and Interface Science, 2022
Slow surfactant redistribution triggers delayed imbibition and sudden fluid rearrangement, producing a non-monotonic dependence of oil displacement on surfactant concentration.
Weipeng Yang, Guoyu Chu, Yujing Du, et al.
Advances in Water Resources, 2022
Salinity-dependent phase behavior creates spatial variations in wettability and interfacial tension, splitting displacement into distinct drainage and imbibition fronts.
Yujing Du, Ke Xu, Lucas Mejia, and Matthew Balhoff
Water Resources Research, 2021
paper / data / research note
Long heterogeneous micromodels separate the effects of polymer elasticity, viscosity, and salinity on trapped-fluid redistribution and recovery.
Lucas Mejia et al., including Yujing Du
Advances in Water Resources, 2021
Mobilized low-viscosity irreducible water can destabilize an otherwise favorable displacement, producing fingers and earlier aqueous breakthrough.
Weipeng Yang et al., including Yujing Du
SPE Journal, 2021
At ultralow interfacial tension, velocity-dependent contact angles can make a water-wet micromodel exhibit drainage-like displacement while in-situ microemulsion fragments the injected phase.
Yujing Du et al.
Water Resources Research, 2020
Microfracture connectivity changes recovery only below a capillary-number threshold, with connected and dead-end fractures producing distinct wettability-dependent flow patterns.
Yujing Du et al.
SPE Journal, 2019
Time-dependent residual-oil dewetting and swelling redirect water toward unswept regions, improving late-time sweep even in the absence of clay.
Lucas Mejia et al., including Yujing Du
Fuel, 2019
Low interfacial tension and transverse viscous pressure gradients—not clearly identifiable wettability alteration—govern matrix-to-fracture oil mobilization in these micromodels.