I think you will find the 13-20TCF is an estimate of one shale formation across that part of the basin.
Similarly, NWE have only provided modeling for 60m,which is still only a section of 1 formation. The 4 formations are 1000 metres thick. I have applied their modeling to the 530m thickness they will be testing.
That does not include the potential for conventional gas in the high cliff sandstones.