Levich Institute Seminar Announcement, 05/10/2005

Tuesday, 05/10/2005
2:00 PM
Steinman Hall, Room #312
(Chemical Engineering Conference Room)

Dr. Stephen Brown
New England Research

"Study of Heterogeneity and Up-scaling in Geologic Media"

ABSTRACT

In rocks and soils, the bulk geophysical and transport properties are determined by the juxtaposition of geometric features at many length scales. We have developed a multi-probe physical properties scanner which allows for the mapping of geophysical properties on a slabbed sample or core at scales from a few millimeters to a meter. Using this device, we can make detailed maps of local properties, including: gas permeability, acoustic velocities (compressional and shear), complex electrical impedance (4 electrode, wide frequency coverage), and ultrasonic reflection (ultrasonic impedance and permeability).

We have used these data to develop a procedure for physically-based up-scaling of petrophysical properties, such as effective bulk electrical resistivity and relative permeability as a function of partial air-water saturation conditions. As an example, we have performed up-scaled the multi-phase flow and transport properties of a seemingly uniform sample of Berea Sandstone. We found that despite the small range of heterogeneity in the local properties, the up-scaling analysis shows that these heterogeneities are still exceedingly important. Under partially saturated conditions, considerable anisotropy in the permeability and electrical resistivity develops as correlated low porosity heterogeneities preferentially fill and hold the wetting phase fluids.


BRIEF ACADEMIC/EMPLOYMENT HISTORY

Stephen Brown is a Principal Scientist at New England Research (1997-present). He was formerly a Senior Scientist at Applied Research Associates (1996-1997), a Member of the Technical Staff at Sandia National Laboratories (1987-1996), a Member of the Professional Staff at Schlumberger-Doll Research (1985-1987), and a post-doctoral research associate at Los Alamos National Laboratory (1984-1985). He received his Ph.D. in geophysics from Columbia University in 1984.

CURRENT RESEARCH INTERESTS


Primary research interests are the mechanical, fluid transport, acoustic, and electrical properties of fractured and otherwise heterogeneous rock and the application of geophysical methods to energy and environmental problems.