TRACER TESTING AT DIXIE VALLEY, NEVADA USING 1-NAPHTHALENE SULFONATE AND 2,6-NAPHTHALENE DISULFONATE

Abstract

The decay kinetics of the candidate tracers 1-naphthalene sulfonate and 2,6-naphthalene disulfonate was studied under laboratory conditions that simulate a hydrothermal environment. Neither of the naphthalene sulfonates exhibited any thermal decay after one week at 330oC, indicating that they are suitable for use in geothermal settings having temperatures of 330oC or hotter. Both tracers 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 less than 0.1 ppb by standard HPLC and fluorescence detection methods. Currently, six naphthalene sulfonates have been tested for use as geothermal tracers. A detailed method for the simultaneous HPLC analysis of all six is presented.