Libyan oil goes to Europe anyway. The main benefit for the US here is not having another expensive, interminable overseas conflict of dubious constitutionality or benefit.
However, being a trader, I look at things rather differently than non-traders.
Libyan crude does indeed flow to Europe. In the absence of Libyan crude, Euro refineries tend to run Brent, and some Urals, although -- Urals being generally sour -- this is less desirable.
No matter who ends up running Libya, that group/faction/whatever is going to have to produce and export in order to pay the bills.
And, like it or not, the WTI-Brent crude spread is going to come in (narrow from it's current $22-23 level) big time. In case you're curious, this spread, WTI-Brent, has historically run from +/- $2-3 dollars/bbl. It's now over $20/bbl.
You do the math. Not all that much difference in a barrel of Brent and a barrel of WTI. Certainly not $20 worth, eh?
Good trading to you!