How deep does villain need to be to go set mining?

[luckbalks]

Does Villain need to have 100bb or more to try and flop a set? What are other factors that come into play when playing small pairs when your facing a 3 bet?

Hand 1
Villain is 18/14/3

Full Tilt Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 6 Players - (LegoPoker HH Converter)

SB: $77.00
BB: $79.75
UTG: $85.70
MP: $137.20
CO: $138.05
Hero (BTN): $137.80

Preflop: Hero is dealt 3[img]/images/graemlins/spade.gif[/img] 3[img]/images/graemlins/diamond.gif[/img] (6 Players)
3 folds, <font color="red">Hero raises to $3.50</font>, SB folds, <font color="red">BB raises to $11.00</font>, Hero ?

Hand 2
Villian is 19/16/6

Fold this to the raise preflop? What if I had 55 but was UTG+1?

Full Tilt Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 5 Players - (LegoPoker HH Converter)

SB: $156.35
BB: $176.15
UTG: $140.85
CO: $98.00
Hero (BTN): $102.70

Preflop: Hero is dealt 5[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/spade.gif[/img] (5 Players)
2 folds, <font color="red">Hero raises to $3.50</font>, <font color="red">SB raises to $11.50</font>, BB folds, Hero ?