Phone conversation with Scott - Jan 12th 2023., page-146

Tight gas is when permeability is lower than 0.1mD. So, for a gas reservoir, any permeability above that figure should flow. Please provide a field example of a gas reservoir which has not flowed when the permeability is less than 5mD? I think you have got mixed up with oil reservoir cut offs.

If the permeability is 1mD after allowing for rel-perm effects, the well productivity can be enhanced by performing stimulation/fracturing provided it's economical.

The 20% porosity was only mentioned by SM with regard to the Pebbly Arkose. SM stated porosities in the UA are up to 15% in well M-1.