Oil prices have climbed 10% since the start of February, so it's no surprise that a couple of oil companies are on IBD's list of the top world stocks. Bermuda-based Energy XXI (EXXI) and top Colombian oil producer Ecopetrol (EC) have posted strong revenue and sales growth over the past three quarters. Both are extended beyond their buying ranges, with Energy XXI 9% above a 34.77 entry from a deep base and Ecopetrol 27% past a 46.10 pivot from a