India’s refiners are sharply increasing purchases of Russian crude oil as premiums have nearly halved to $5-6 per barrel from a high of $10-12 immediately after the start of the West Asia war. This provides critical cost relief to them at a time when West Asia crude premiums, freight charges and war-risk insurance costs, have surged due to disruptions around the Strait of Hormuz, a senior oil industry official, who did not wish to be identified, said.