Greatly Enhanced Detectability of Geothermal Tracers Through Laser-Induced Fluorescence

Technical Report · Wed Oct 30 04:00:00 EST 2002

DOI:https://doi.org/10.2172/806819· OSTI ID:806819

Rose, Peter ^[1]; Harris, Joel; Kilbourn, Phaedra; Kleimeyer, James; Carter, Troy

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1. Energy & Geoscience Institute at the University of Utah

WE have successfully completed a four-year R and D project to greatly reduce the detection limit of fluorescent tracers through the use of emerging laser-excitation, optical fiber, and CCD-spectroscopy technologies. Whereas the efforts over the first two years were directed at demonstrating a reduction in the detection limit of fluorescent compounds by a factor of 100 and at identifying several new fluorescein-derived tracer candidates, our recent efforts were focused primarily on the field demonstration of new tracers having detection limits in the low parts-per-quadrillion range. During the summer of 2001, we initiated field tests at the Dixie Valley, Nevada and at the Beowawe, Nevada geothermal fields using very small quantities of the fluorescein-derivative 6-carboxyfluorescein. Subsequently, we succeeded in measuring sub-part-per-trillion quantities of that candidate tracer at both the Beowawe and Dixie Valley geothermal reservoirs-using approximately 530 g of tracer at each setting. Our studies indicate that we could have observed a breakthrough using only 0.53 g of 6-carboxyfluorescein. This represents a reduction by a factor of 170,000 below the mass of tracer used in a previous tracer test at Beowawe.

• Research Organization: University of Utah/Energy and Geoscience Institute/Department of Chemistry (US)
• Sponsoring Organization: (US)
• DOE Contract Number: FG07-98ID13619
• OSTI ID: 806819
• Report Number(s): DOE/ID/13619
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
FIELD TESTS
FLUORESCENCE
GEOTHERMAL FIELDS
Geothermal Legacy
NEVADA
OPTICAL FIBERS
SENSITIVITY