Just because you have the lease does not mean the feds will permit drilling there. Nor does that prevent them promulgating regulations or making rulings that you must jump through hoops which make a well cost-prohibitive, even at today's pices.
Even known producing zones will not be drilled if the BLM can stop it and wants to prevent it (think National Forrest, National Grasslands). The Federal Government owns over half of the land west of the Mississippi, and I have seen individual BLM people who treat that land as their personal fiefdom, which might not be all bad, but there are a lot of dirt worshippers in the bunch.
I didn’t know about the Bureau of Land Management and the oil leases. Thank you for that info.