I have run across abbreviations with an apostrophe (') indicating a measurement in feet. Is that correct? These abbreviations are FNL, FWL, FSL. Should these things mean anything to me. Also, I have run across the term "ground" with a number before it. There is also a number in front of "Bakken". Both of those numbers look like measurements in feet. Does the number in front of Bakken indicate the amount of feet they have drilled horizontally or vertically?
From north line, from west line, from south line, it's how they define a position with great accuracy, like where the head of the well is, or exactly where the wellbore is, or it's end which is the total depth counting the verticle and horizontal parts.
I don't recall seeing "ground" with numbers, if I knew where you were seeing this, it might help. Possibly it's feet above sea level.
As for Bakken, there is an upper, middle and lower Bakken and I have seen numbers 1,2,3, next to Bakken and I think they may be shorthand for upper, middle, lower.
The Bakken can be grouped with the Three Forks because some say they communicate. This would probably only matter if you had a poor depth severance clause that used formations rather than xxx feet above/ below the depth being produced, because, who is to say where one closely spaced formation begins and another ends? Eoes it really matter when the operator can claim the formations communicate thus he's already holding all he wants by production?
I hope this helps.