Oil prices edged lower after a choppy session as traders weighed diplomatic progress in the Middle East against rising Russia-Ukraine tensions. West Texas Intermediate traded below $82 a barrel, taking this week's drop to about 6%, while Brent closed below $88. Futures rose on Wednesday on a report that Russian President Vladimir Putin was planning an escalation in Ukraine, before reversing those gains after Iran's military said it reached a revenue-sharing agreement with Oman on the Strait of Hormuz. Dan Tannebaum, Global Anti-Financial Crime Practice Leader at Oliver Wyman, discussed the US "economic D-Day" against Iran in a related video segment.