Chances of Hope Boules hitting a gusher

I refer everyone to Mowibble's map on the Drilling thread.

I am just wondering, although the field where they are drilling does indeed seem prolific in terms of the amount of successful wells drilled ( heaps ) VS dusters ( none !! )....how does oil prospecting work ? could they hit a real gusher with their drill that flows much harder and longer than everything around them ? I mean.....if everyone else has had good results but nothing epic.....

I guess its like looking for gold ?