There are several ways for stimulating these types of tight carbonate rocks.

1. By injecting CO2 above supercritical pressure and temperature conditions with brine solution. Where CO2 will dissolve in the brine solution and will form carbonic acid, which will then provide the stimulation in the tight core sample to increase the permeability.

2. You can use acid for stimulation purposes. Like Hcl 10% to 15% will be useful for this purposes. or mud acid, which will surely increase the permeability.

3. You can use fracturing techniques, like using hydraulic fracturing or liquid nitrogen fracturing by providing sudden shock to the core sample.