Ukraine's deep-strike drone campaign targeting Russia's oil and gas production facilities has already cost its enemy 10 percent of its refining capacity, according to industry experts -- and Kyiv is committed to stepping things up. "Ten percent, it's not an astonishing number," says Tatiana Mitrova of Columbia University's Center on Global Energy Policy. "But it is still something that starts to be felt with the Russian domestic fuel crisis, with reduced oil refined products exports, and general tension inside the Russian oil sector." Ukraine has…