NEW YORK ( TheStreet) - Weatherford Interantional ( WFT), Cabot Oil & Gas ( COG), Helix Energy Solutions ( HLX) and Cameron International ( CAM) were top performers this week, while SunPower ( SPWRA), Cobalt International Energy ( CIE) and Whiting Petroleum ( WLL) eroded substantial value.Among the advancers this week, Weatherford International topped the charts, gaining 14% as equity analyst William Conroy at Pritchard Capital Partners raised the stock to buy from neutral with a target price of $29 per share. Helix Energy Solutions rose 8.4% on the week after reporting profit. The second-quarter 2011 EPS stood at 39 cents per share compared to net loss of 82 cents in the corresponding quarter of 2010. Cameron International rose 6.5% after the company posted better-than-expected results and raised its 2011 guidance. Revenue and EPS for the second quarter stood at $1.65 billion and 66 cents, respectively. The company observed a 72% jump in orders during the quarter over the same quarter prior year. >> Keep the stock market at your fingertips with TheStreet's iPad app. Cabot Oil & Gas advanced 6.3%. EQT ( EQT) rose 3.6% after better-than-expected results. Net income was $77.5 million, topping the estimated $63.5 million. EPS stood at 51 cents. Range Resources ( RRC) increased 3.6% after Citi raised the stock to hold from sell. SandRidge Energy ( SD) advanced 2.9% for the week. Superior Energy Services ( SPN) moved up 2.6% as the company has raised its 2011 EPS guidance to $1.96 to $2.16 per share vs. the earlier guided $1.62 to 2.02 per share. Among other movers, Williams Companies ( WMB), Complete Production Services ( CPX), Noble Energy ( NBL) and Holly Energy Partners ( HEP) added around 2%. SunPower was the top lagger, shedding 15%. The company reported higher-than-forecast net loss. Stifel Nicolaus equity analyst at Jeff Osborne has downgraded the stock to sell from hold. Cobalt International Energy shed 14.2%. Whiting Petroleum declined 10.6% as BMO equity analyst Philip Jungwirth downgraded the stock to market perform from outperform with a target price of $65 per share. GT Solar International ( SOLR) retreated 9.9% as Credit Agricole Securities equity analyst Mark Heller has downgraded the stock to underperform from outperform with a target price of $16 per share. Among other movers, Carbo Ceramics ( CRR) fell 9%, Swift Energy ( SFY) reduced 8.9%, Oasis Petroleum ( OAS) pared 8.2% and Occidental Petroleum ( OXY) declined 7.7% for the week.