This week was a mixed one for investors in the energy sector. While oil prices hit new highs for the year, that rising tide didn't lift all boats.

If fact, several energy stocks were down by more than 10% this week after delivering disappointing news to investors. Three of the biggest losers, according to S&P Capital IQ data, were GulfMark Offshore (NYSE: GLF)Peabody Energy (OTC:BTUU.Q), and Natural Resource Partners (NYSE:NRP). To learn more about the news that drove these stocks lower, check out the slideshow below.