This might be going off into the weeds, but published work on field and lab testing of formation damage effects on injectivity of injection wells should prove useful.
Injectivity tests on the sidewall core with the planned drilling mud (with and without Fracseal) will provide you with a baseline and altered permeability ratio vs core effulent plot which will be useful in characterizing the extent of the formation damage. Backflushing (reverse flow through the same core) and the resulting perm ratio will give you a good idea on the skin damage "post production".
A similar process is detailed in SPE 39487 (Nasr-El-Din, 1998) on restoring the injectivity of waste water disposal wells - See Fig 5.
Nasr-El Din along with other workers have provided guidance on core length/size and preparation methods to minimize negative lab/core preparation effects on the results as well.Core Flooding as Related to Water Injection (Heriot-Watt University, 1999)
You may also consider the particle size distribution (in microns) of the Fracseal and the pore throat sizing of the target formation. Pore throat plugging which contributes to the formation damage may also occur if there is a significant distribution of the Fracseal particles smaller than the pore throats.
Any natural fracturing of the formation may also complicate the analysis - the Heriot Watt reference does provide a method to consider this in the lab testing.