Russian crude is piling up at sea as India’s refiners step back from purchases, leaving Moscow with millions of barrels on tankers and fewer clear outlets for its oil exports. Russia shipped an average of 3.18 million barrels per day of crude in the four weeks to January 25, according to vessel-tracking data compiled by Bloomberg. That volume was little changed from the prior week but down by about 680,000 bpd from the pre-Christmas peak and the lowest level since August. The bigger issue is not how much Russia is shipping, but where those…