Um, sorry, obviously I am not understanding something. None of my units can target these mines. Again: They are flagged as "invulnerable" and "phased out". The gravity wells I conquer are still full of them, and when there is nothing left in the gravity well belonging to my enemy (I chased him out, killed all ships and all structures), his mines are still there, I can see them, but I cannot shoot them, neither with my ships nor my defensive structures I subsequently build. The only way they seem to dissapear is if I have to leave the system via a jump lane which they appear to block -- then they detonate on me. None of my ships will target them automatically, and when I try to target them manually, I merely move towards them. So, again, I am either missing something obvious or have some sort of bizarre problem.

Reveal mines is an ability of the scout. Its automatically set to auto cast but you can tell it to use on a particularly large group of mines to speed things up. It has a cooldown of 2 secs so its pretty quick.

Careful of Advent mines however as they will home in on the scout as they are revealed.   

Yes, you can see the mines in the gravwell. It's hard-coded that way. But you cannot target them unless a scout is close to them.

Thank you, understand now.