NEW YORK ( TheStreet) - Petrohawk Energy ( HK), Bill Barett ( BBG), Comstock Resources ( CRK) and Forest Oil ( FST) clocked smart gains during the past week, while Core Laboratories ( CLB), Energy Transfer Equity ( ETE), Lufkin Industries ( LUFK) and TransAtlantic Petroleum ( TAT) fared badly.Among the advancers for the week, Petrohawk Energy topped the charts, gaining 63%. Bill Barett jumped 17%. Bill Barett stock was raised to outperform at Wells Fargo. Comstock Resources rose 15.7%, Forest Oil Corporation edged up 15.2% and Pioneer Natural Resources ( PXD) moved up 14.3%. Range Resources ( RRC) advanced 14.4% after the management announced an 8% increase in second-quarter production volume from the prior year quarter and a 10% boost in 2011 production. Meanwhile, the company's price realization for the quarter increased 11%. Other movers were Pioneer Natural Resources ( PXD), up 14.3%, while Cabot Oil & Gas ( COG) rose 14% and Berry Petroleum Company ( BRY) improved 13.3%. EQT Corporation ( EQT) edged up 12.7% after the stock was raised to outperform from neutral at Robert Baird with a price target of $66 per share. Chesapeake Energy ( CHK) moved up 12.5% and Bloomberg reports that the company is likely to announce a new natural gas discovery in the Utica Shale formation shortly. Oasis Petroleum ( OAS) advanced 12.4% and Whiting Petroleum ( WLL) increased 12.3%. Stocks like Swift Energy ( SFY), Denbury Resources ( DNR), Nabors Industries ( NBR) and Gran Tierra Energy ( GTE) gained more than 10% during the week. Southwestern Energy ( SWN) soared 11% after the stock's target price was raised to $57 per share from $48 at Howard Weil. Core Laboratories was the top laggard, down 5.8%, while Energy Transfer Equity lost 4.5%, Lufkin Industries erased 3.8% and TransAtlantic Petroleum reduced 3.2%. CNOOC ( CEO) trimmed 3.2% as the company intends to purchase Opti Canada, an oil-sands producer. Jefferies Group believes that it is a high-risk buy for CNOOC. The brokerage values Opti's production at about $275,000 per barrels per day and estimates proved and probable reserves at $3.54 a barrel. Energy Transfer Partners ( ETP) fell 2.9% after S&P cut the company's outlook to negative from stable. Other losers included Frontline ( FRO), Spectra Energy Partners ( SEP), Teekay Offshore Partners ( TOO), Targa Resources Partners ( NGLS) and Williams Partners ( WPZ).