(Update, April 2: It appears "movement" has happened on Iran nuclear talks. That's probably worth a $1/bbl cut right there. At a minimum, sanctions against Iran won't get any stiffer. And, if progress continues in advance of the June 30 final deadline, the P5+1 might slightly relax, at least, some of the sanctions. And, as Chris Tomlinson notes, Iran-Saudi Arabia tussles could lead the Saudis to pump even more.)
Meanwhile, what effect will this have, or not have?