Tracer candidates that pass the thermal stability tests mentioned above are subject to static batch sorption experiments. Crushed reservoir or reservoir-like rock is added to the same type of vial as used above. Convenient test materials are sandstone (Berea, Clashack, Bentheimer, Felser, etc.) and chalk, which represent the main reservoir rock types, and kaolinite, which represents clays that are nearly always present to some degree.

The survivability yield, Y, is calculated from Eq. (15). One example of a static sorption curve is given in Fig. 35.

As can be seen in the example given, there is a clear indication of sorption to sandstone (Clashack) whereas sorption to the other substrates is not detectable. The decrease in the Y values for chalk and clays is due to the thermal degradation data given in Fig. 35.