An traditional oil tracer can also be dissolved in gas. Tracers that can also move from one oil to gas or opposite during flow in the wellbore. The traditional method to distinguish between oil and gas is to compare lab measured release with concentration from well samples. This is uncertain since the absolute release can be difficult to predict accurately due to decline during aging, dilution, partly exposed rods, hysteresis effects due to alternating wetting of oil/gas, etc.

DualTrace is a patented method to overcome this uncertainty. Combined tracers are installed at the same station. These are both releasing in exposure to oil and gas, however, at a significant different rate. By comparing the ratio between them, instead of the absolute release in a single tracer, most of the uncertainty is eliminated.