By Dan Weil Oil companies are thriving, with crude prices soaring surging 34% so far this year. Earnings are scheduled for coming weeks. With oil prices surging 34% so far this year, it’s a good time for big oil companies. Earnings reports from most of the majors are due in the next few weeks. So Barron’s created a list of the companies that have seen the biggest increases in earnings estimates from analysts this year. Marathon Petroleum (MPC) – Get Marathon Petroleum Corporation Report. As a big oil refiner, “it has benefited from the increase in demand for petroleum products like diesel fuel…