TRACER TESTING AT DIXIE VALLEY, NEVADA, USING 2-NAPHTHALENE SULFONATE AND 2,7-NAPHTHALENE DISULFONATE

Abstract

The decay kinetics of the candidate tracers 2-naphthalene sulfonate and 2,7-naphthalene disulfonate was studied under laboratory conditions that simulate a hydrothermal environment, with neither compound exhibiting any decay after one week at 330oC. These data indicate that these compounds are more thermally stable than any of the previously studied polyaromatic sulfonates. Both of the tracer candidates were successfully tested in a field study at the Dixie Valley, Nevada, geothermal reservoir. In addition to being environmentally benign, affordable and very thermally stabile, these two compounds were shown to have excellent detection limits of approximately 200 parts per trillion by standard HPLC and fluorescence detection methods.