Ferrofluids for Subsurface Flow Control and Imaging

IB-1331

E.O. Lawrence Berkeley National Laboratory

APPLICATIONS OF TECHNOLOGY:

• Subsurface barriers and reactants
• Imaging and tracing liquids in subsurface

ADVANTAGES:

• Ferrofluid distribution dependent on magnetic forces

ABSTRACT:

A team led by George Moridis of Berkeley Lab has confirmed that magnetic forces can be used to accurately and effectively guide ferrofluids to target zones in heterogeneous porous media. Once emplaced in the subsurface at a contaminated site, the ferrofluids may act as reactants for treatment, or as barrier liquids (low viscosity permeation grouts) for containment. Ferrofluids are stable suspensions of colloidal ferromagnetic particles in a carrier liquid. Brownian motion keeps the particles suspended while a dispersant coating prevents agglomeration. Ferrofluids move as a homogeneous single-phase fluid under the influence of a magnetic field. This attribute is responsible for a unique property of ferrofluids: they can be manipulated in virtually any fashion, defying gravitational or viscous forces in response to external magnetic fields. Numerical simulation capabilities for ferrofluid flow developed by Curt Oldenburg can be used to design and test the flow processes of ferrofluids in response to magnetic and gravitational forces. In laboratory experiments carried out by Sharon Borglin, it was shown that the final ferrofluid distribution depends only on the magnetic field and is unaffected by the heterogeneity of the hydraulic properties. This finding makes ferrofluid treatment and containment technologies (based on the targeting capabilities of ferrofluids with appropriate carrier liquids) very promising for heterogeneous subsurface systems. In addition, ferrofluids may find application as tracers for detecting and imaging the movement and position of liquids in the subsurface.

STATUS: Patent Pending. Available for licensing

REFERENCE NUMBER: IB-1331