Oil barely budged this week, closing down less than 2% and just below $48.50 per barrel. That was actually a surprisingly tame response to another failed OPEC meeting, after the organization couldn't come to an agreement on a production ceiling. OPEC's failure didn't seem to faze oil stocks, many of which rallied sharply this week.

According to S&P Global Market Intelligence data, among the best-performing energy stocks this week were EXCO Resources (NYSE:XCO), Energy Transfer Equity (NYSE:ET), NGL Energy Partners (NYSE:NGL), Enerplus (NYSE:ERF), and Capital Product Partners (NASDAQ:CPLP)

There wasn't one specific catalyst that fueled these strong gains. Energy Transfer Equity, for example, jumped because its merger partner is reportedly open to considering a restructured deal to save their failing merger. Meanwhile, Enerplus closed on its equity offering, which brought in some much-needed cash to pay down debt and fund capital expenditures. 

EXCO Resources and NGL Energy Partners, on the other hand, seemed to rally mainly due to a follow-through from news announced last week, though NGL Energy Partners was also upgraded by an analyst. That said, Capital Product Partners really didn't have any specific catalyst fueling its big move, other than the fact that the oil and capital markets are starting to show signs of improvement, which bodes well for the company's future. 

To learn more about why these stocks moved so sharply, check out the following slideshow.