0951 GMT - European energy majors' earnings are set to more than double on the same period last year, Barclays analyst Lydia Rainforth writes. The sector should report earnings close to $35 billion with underlying free cash flow around $45 billion, she says. The benchmark refining margin is at unseen levels of around $40 a barrel, which, coupled with trading, will drive downstream earnings, she adds. Meanwhile, European natural gas prices are the key driver of upstream earnings, she says.