| Title | EXPERIMENTAL EXAMINATION OF ADSORPTION OF THE NAPHTHALENE SULFONATES UNDER GEOTHERMAL CONDITIONS |
|---|---|
| Authors | L. Sajkowski, B.W. Mountain, T.M. Seward |
| Year | 2018 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Tracer studies, adsorption, naphthalene disulfonic acid, naphthalene sulfonic acid, NDS, NSA, experimental geochemistry |
| Abstract | Naphthalene sulfonates (NDS and NSA) are widely used in the geothermal industry as reservoir tracers. However, there is little experimental data on the adsorption of these compounds under geothermal conditions. Knowledge of the adsorption effect is essential to correctly interpret tracer test results. In this preliminary study, we have investigated the possibility of tracer adsorption onto rock surfaces under geothermal conditions. Six tracers: 2-naphthalene sulfonate, 1-naphthalene sulfonate, 1,5-naphthalene disulfonate, 1,6- naphthalene disulfonate, 2,6- naphthalene disulfonate and 2,7- naphthalene disulfonate were used. A continuous flow-through apparatus was used in which a small amount of the six tracer mixture was injected into the flow of geothermal brine. The pressure vessel was filled with either quartz or greywacke material. The experiments were conducted at three temperatures: 22°C, 100°C and 250°C. Samples were collected every hour after injection. Samples were analysed for tracers by high performance liquid chromatography (HPLC) using fluorescence detection. The results show the following: no observable difference in breakthrough time for different tracers; decrease in breakthrough time with increased temperature; possible weak adsorption of tracers in the greywacke experiments; decrease of integrated tracer concentration at 250°C suggests the onset of thermal decay. |