The Advanced Energy Consortium Nano-metrology lab: Mohsen Ahmadian Ph.D.
The Advanced Energy Consortium (AEC), which has established a nanotechnology laboratory at the core research center (CRC) of the Bureau of Economic Geology (BEG), room 2.220, is undertaking an extensive metrology study to compare and catalog magnetic nanoparticles (MNPs) for their usefulness in illuminating waterflood and frac-network imaging. The lab is managed by Dr. Mohsen Ahmadian, a project manager and scientist at the BEG since early 2010, who manages two research programs for the AEC (Contrast Agents and Nanomaterial Sensors). This research is being conducted in collaboration with scientists at leading universities in the USA, Europe, and South America (including BU, Duke, Harvard, Lawrence Berkeley National Lab, OU, Rice, RTI, TNO, UNC, and UT) and member companies (BG, BP, Petrobras, Schlumberger, Shell, Statoil, and Total).
The Contrast Agent Program aims at synthesizing and characterizing various nanoparticles (including MNPs) that will be used for "illumination" of subsurface reservoirs fluids. The immediate need is to examine the usefulness of MNPs with high magnetic permeability ()as passive tracers that will travel in the injected-waterflood front and that could be imaged using existing electromagnetic cross-well geophysical tools. We postulate that this technology will improve the resolution and depth of investigation beyond those of current logging techniques.
So that characterization of various MNP contrast agents being synthesized might be expedited, the nanometrology lab was established. The lab's charter is to determine the relationship between physical and chemical characteristics of nanoparticles (composition, size, crystallinity, surface coating, etc.) and the magnetic permeability of the nanoparticle materials. The group is also focused on (1) procurement and characterization of available nanomaterials for identification of affordable and suitable candidates for a "proof-of-concept" field experiment currently being planned and (2) synthesis and characterization of new designer ferrite materials having higher magnetic permeability and coatings that may be more appropriate for large-scale commercial applications. Through collaboration with other scientists (Dr. Vicki Colvin at Rice and Dr. Keith Johnston at UT), we have already developed a standardized metrology protocol for analyzing MNP samples that will enable us to easily compare and contrast suitable nanomaterial options. As far as we can determine, no one has ever cataloged, characterized, or quantified the influence of physical and chemical parameters on magnetic response using such a rigorous and systematic approach on such a large sample of nanoscale materials.
Through generous grants from AEC member companies and matching funding from the JSG equipment committee, the lab has purchased its first piece of equipment, a Vibrating Sample Magnetometer (VSM). Until now we have been forced to rely on the Superconducting Quantum Interference Device (SQUID) at Rice University for measurement of magnetic properties of nanoparticles. However, owing to the low throughput of SQUID and the cost of liquid helium required for cooling its superconducting coils, few samples could be measured. We therefore found other equipment to speed up the required magnetic characterization. The VSM was identified as a much higher throughput alternative (>6× SQUID's throughput) that was suitable for detailed analysis of magnetic characteristics of nanoparticles, including full hysteresis loop and initial magnetic permeability measurements at a field-intensity range of 0 to -/+1.7 Tesla at a temperature range of -40° C to 800° C.
The availability of the VSM at the BEG will add to our repertoire of existing nanogeoscience tools. Furthermore, this tool will encourage new collaborative research and training opportunities for JSG students and research staff interested in the nanogeosciences, magnetics, paleomagnetics, and metrology. The successful implementation of these tools in the AEC's nano/metrology lab will most likely lead to additional funding opportunities for hiring students and postdocs through either the AEC or external funding agencies.