Literally, PlumeStop will not penetrate ‘clay’ any more than injected water would during the period of injection. Practically, the question would first need to determine the particular definition of clay; for example whether the use would be in a pure, competent clay or simply a clay-rich formation. PlumeStop will distribute through the mobile porosity of a formation – it can be fracture-emplaced but this is not necessarily beneficial. From the mobile porosity, it will ‘draw out’ contamination from the immobile porosity, such as from a clay zone for example. In that manner, it will be effective in clays drawing contamination out of the same, and this efficacy will be long-lived (we would predict decades).
Beyond this, if contamination has entered the ‘clay’ at all, then it follows there must be mobile porosity zones within the clay through which this has occurred, whether these be higher-permeability strata, lenses or fractures. It would follow that PlumeStop would similarly be injectable through such zones, and once emplaced, it would both capture the contamination within the zone and draw out contamination from the adjacent low-perm zones as described above.
One of the key features of PlumeStop is its utility for controlling back-diffusion from low-permeability zones following its easy dispersion through the mobile porosity. The above mechanisms would be an example of this.
If the site permeability is particularly low through the majority of the formation however, PlumeStop may not be the solution for the site.