Greatly Enhanced Detectability of Geothermal Tracers Through Laser-Induced Fluorescence

Rose, Peter ; Harris, Joel ; Kilbourn, Phaedra ; Kleimeyer, James ; Carter, Troy

University of Utah/Energy and Geoscience Institute/Department of Chemistry (United States)

关键词: Geothermal Fields;    Fluorescence;    Geothermal Legacy;    Sensitivity Geothermal Legacy;    Optical Fibers;   

DOI  :  10.2172/806819
RP-ID  :  DOE/ID/13619
RP-ID  :  FG07-98ID13619
RP-ID  :  806819

美国|英语

来源: UNT Digital Library

【 摘 要 】

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.