Mumbai, Dec. 18 -- WTI crude oil futures climbed above $56 per barrel, supported by concerns over potential supply disruptions from Venezuela and Russia. Markets turned cautious after US President Donald Trump announced a blockade on sanctioned oil tankers linked to Venezuela, raising worries over export flows. At the same time, Washington is moving toward tougher energy sanctions on Russia to push Ukraine peace talks, adding to global supply concerns. Official EIA data showed US crude inventories fell by 1.3 million barrels for the week ending December 12, lending further support to prices. February WTI futures traded near $56.35, up nearly 1%. On MCX, January crude futures rose to Rs.5113 per barrel, up 0.2%. The dollar index hovered near...