Research Interests:
Interfacial Phenomena
Wettability
Flow and Transport Through Porous Media
NMR Fluid and Rock Properties
Surfactant/Foam Flooding

Education:
B.S. (1963) Lamar University
Ph.D. (1967) Rice University

Professor Hirasaki joined the Rice faculty after a 26 year career with Shell Development and Shell Oil Company. His research in fluid transport through porous media ranged from the microscopic scale intermolecular forces governing wettability to the megascopic scale numerical reservoir simulators for field-wide modeling.

A reoccurring theme throughout this research is the dominance of interfaces in the determination of fluid transport processes. Fluids flow through rock and soil in pore spaces that are on the order of microns. The relative transport of phases and components are governed by the degree of wetting of the solid by the fluid phases and the sorption of species on the fluid and solid surfaces in addition to the usual transport coefficients such as viscosity and diffusivity.

Professor Hirasaki’s research program is sponsored by an industrial consortium, USDOE, and SERDP of the USDOD.

NMR Fluid and Rock Properties: The petroleum industry uses nuclear magnetic resonance (NMR) well logging to evaluate the formation properties immediately after a well is drilled. Similar measurements are made in the laboratory with fluid and rock samples to develop the methodology to interpret the NMR signals. This investigation is in collaboration with Professor Kishore Mohanty at University of Houston.

Wettability in Petroleum Systems: Water, oil, and gas exists in porous rocks with a large specific surface area. The wetting and/or spreading of the fluids on the solid and/or fluids govern the ease of recovery of the hydrocarbons from the rock formation. Research is being conducted to understand fundamental mechanisms of wettability and to enhance the imbibition of water into carbonate rocks. This investigation is in collaboration with Professor Mukul Sharma at The University of Texas.

Asphaltene Deposition: Asphaltenes exists crude oil as a colloidal dispersion. This is the component that is responsible for wettability alteration in petroleum reservoirs. When asphaltene precipitation and deposition occurs during production, it can result in plugging of productions systems. The thermodynamics and surface chemistry of asphaltene precipitation and deposition is investigated in collaboration with Professor Walter Chapman and with Dr. Jill Buckley at New Mexico Tech.

Surfactant/Foam Transport: Some enhanced oil recovery processes and soil remediation processes are based on creating additional interfaces through the application of surface active materials called surfactants. These materials promote the "mixing of oil and water" by creation of nanostructures that can reduce the oil-water interfacial tension by a factor of 10E-4 and or solubilize oil into an aqueous phase containing dispersed sufactant aggregates called "micelles" They can also stabilize thin water films so that gas will flow as a dispersed "foam" phase that transports as if it is a highly viscous fluid. This investigation is in collaboration with Professor Clarence Miller.

Gas Hydrates: Gas hydrates currently are important in the seafloor pipeline transportation of oil and gas, a potential natural gas source for the future, and have been a cause for climate change in the geological past. An initiative on gas hydrates is sponsored by the Shell Center for Sustainability.

Selected Publications:
G. J. Hirasaki, R. E. Jackson, M. Jin, J. B. Lawson, J. Londergan, H. Meinardus, C. A. Miller, G. A. Pope, R. Szafranski, and D. Tanzil, "Field Demonstration of the Surfactant/Foam Process for Remediation of a Heterogeneous Aquifer Contaminated with DNAPL," NAPL Removal: Surfactants, Foams, and Microemulsions, S. Fiorenza, C. A. Miller, C. L. Oubre, and C. H. Ward, ed., Lewis Publishers (2000).
G. Q. Zhang, G. J. Hirasaki, and W. V. House, "Effect of Internal Field Gradients on NMR Measurements," Petrophysics, 42, No. 1 (Jan.-Feb. 2001), 37-47.
D. Tanzil, G.J. Hirasaki, and C.A. Miller, "Mobility of Foam in Heterogeneous Media: Flow Parallel and Perpendicular to Stratification," SPEJ, (June 2002) 203-212.
S.-W. Lo, G.J. Hirasaki, W.V. House, and R. Kobayashi, "Mixing Rules and Correlations of NMR Relaxation Time with Viscosity, Diffusivity, and Gas/Oil Ratio of Methane/Hydrocarbon Mixtures," SPEJ, (March,2002), 24.
G. J. Hirasaki and S.-Y. Yang, ãDynamic contact line with disjoining pressure, large capillary numbers, large angles and pre-wetted, precursor or entrained films,ä Contact Angle, Wettability and Adhesion , Vol. 2 , K.L Mittal, ed., VSP, Boston (2002), 347-376.
G. J. Hirasaki, S.-W. Lo, Y. Zhang, ãNMR Properties of petroleum reservoir fluids,ä Magn. Reson. Imaging , 21 (2003), 269-277.
G. Q. Zhang and G. J. Hirasaki, ãCPMG relaxation by diffusion with constant magnetic field gradient in a restricted geometry: numerical simulation and application,ä J. Magn. Reson ., 163 (2003) 81-91.
P. David Ting, George J. Hirasaki, and Walter G. Chapman, "Modeling of Asphaltene Phase Behavior with the SAFT Equation of State," Petroleum Science And Technology , Vol. 21, Nos. 3 & 4, pp. 647ö661, 2003.
A. Pena and G. J. Hirasaki, ã Enhanced characterization of oilfield emulsions via NMR diffusion and transverse relaxation experiments,ä Adv. Colloid & Interfacial Sci . , 105 (2003) 103-150.
Surface Chemistry of Oil Recovery From Fractured, Oil-Wet, Carbonate Formation,ä George Hirasaki and Danhua Leslie Zhang, SPE 80989 prepared for presentation at the SPE International Symposium on Oilfield Chemistry held in Houston, Texas, U.S.A., 5ö8 February 2003.