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).