Russian oil companies are priming the pumps to significantly boost crude output this summer, taking on an unusually important role in a global effort to keep prices in check. Alongside Saudi Arabia, Russia is one of just a few countries that can quickly ramp up production, a capability that could help a group of big producers—who agreed in late June to boost output —as they try to cool a sizzling global oil market. About 18 months after the Saudi-led Organization of the Petroleum Exporting Countries began limiting supply amid lower prices, the group has the opposite problem. Stored inventories of crude have fallen, demand is strong and supply has been disrupted in Iran, Venezuela, and Libya. That has all conspired to send prices sharply higher. U.S. crude hit 3½-year highs last week. On Saturday, President Donald Trump called on Saudi Arabia to boost production to help meet […]