HEADS UP NL100 - set facing river shove

$0.50/$1 No Limit Holdem
OnGame
2 Players
Hand Conversion Powered by weaktight.com

Stacks:
SB AlbanJuen ($101.50)
BB Hero ($187.50)

Pre-Flop: ($1.50, 2 players) Hero is BB
AlbanJuen raises to $3, Hero calls $2

Flop: ($6, 2 players)
Hero checks, AlbanJuen checks

Turn: ($6, 2 players)
Hero checks, AlbanJuen bets $4.50, Hero raises to $12, AlbanJuen calls $7.50

River: ($30, 2 players)
Hero bets $15, AlbanJuen goes all-in $86.50

Final Pot: $131.50

We just started a session, maybe 20 or something hands. I dont have any reads on oponent. He represents flush and maybe streight but the problem is he raised preflop and didnt cont bet on flop. I dont see many people checking back flush or steight draws in position when the raised PF.

I put him on some random ace and thay why i value bet river only half of pot but when he shoved i got into problems.. I dont see him turning ace into bluff here.

Any ideas....

easy fold