NEW YORK ( TheStreet) -- Shares of Complete Production Services ( CPX), Cobalt International Energy ( CIE), Gran Tierra Energy ( GTE) and ReneSola ( SOL) made gains last week, while shares of First Solar ( FSLR), Superior Energy Services ( SPN), Chesapeake Midstream Partners ( CHKM) and TransAtlantic Petroleum Ltd. ( TAT) fell.Complete Production Services led the pack of winners last week, gaining 53.2%. Cobalt International Energy rose 26.4%. Gran Tierra Energy improved 25.3%. The company starts exploration drilling operations on two oil prospects in Brazil, as per International Resource News. ReneSola increased 23.8%. Other movers were Frontline Ltd. ( FRO) (up 23.0%), Oasis Petroleum ( OAS) (up 22.7%), Forest Oil Corp ( FST) (up 22.6%) and Denbury Resources Inc ( DNR) (up 22.0%).