NEW YORK (TheStreet) -- Key Energy Services (KEG), EV Energy Partners (EVEP), Tesoro (TSO) and Complete Production Services (CPX) were top performers last week, while J.A. Solar (JASO), Forest Oil (FST) and Trina Solar (TSL) eroded substantial value.Among the advancers the past week, Key Energy Services and EV Energy Partners topped the charts, gaining 10.9% and 10.8%, respectively. Tesoro rose 10.7% over the week, as Barclays Capital has raised the stock's rating to overweight from equal weight with a target price of $37 per share. Tesoro's Los Angeles refinery, temporarily shutdown, is ramping up towards normal operations. Complete Production Services rose 10.1% after J.P. Morgan rated the stock overweight with a target price of $42 per share. InterOil ( IOC) and SunPower ( SPWRA) gained 9.8% and 9.5%, respectively. Oil States International ( OIS) moved up 9.3% as CLSA has raised the stock's rating to buy from outperform. The brokerage has raised the target price to $95 per share from $94. Halliburton advanced 9% this week. G.T. Solar ( SOLR) rose 8.7% after receiving equipment orders worth $81.7 million from two customers in Asia. The orders were for equipment to produce poly-silicon used in the manufacture of solar cells. Among other movers, Patterson-UTI Energy ( PTEN) advanced 8.6%, RPC Inc ( RES) rose 7.7%, Superior Energy Services ( SPN) grew 7.7% and Seacor Holdings ( CKH) added 7.4%, Helmerich & Payne ( HP) moved up 7.4% last week after signing agreements to build and operate 12 FlexRigs, for delivery to eight exploration and production companies during fiscal 2012. Oceaneering International ( OII) gained 7.1% during the week. National-Oilwell Varco ( NOV) piled 6.8% on plans to acquire Ameron International, a manufacturer of fiberglass-composite pipes for a consideration of $85 per share in all an all-cash transaction valuing Ameron at $772 million, or 7.1 times its estimated 2012 EBITDA. Other winners included Whiting Petroleum ( WLL) up 6.6%, while Continental Resources ( CLR) gained 6.3%. Atlas Energy ( ATLS) rose 6.2%, whereas Anadarko Petroleum ( APC) and Schlumberger ( SLB) gained 6.1% each. Nexen ( NXY) improved 6.0%, Concho Resources ( CXO) piled 5.8% and YPF ( YPF) advanced 5.8%. J.A. Solar Holdings was the top lagger, shedding 8.2% as a drop in polysilicon prices could affect the company's competitiveness. The company has signed long-term purchase contracts with producers like GCL-Poly Energy Holdings and Wacker Chemie. Forest Oil Corporation shed 7.5%. Trina Solar declined 5.6% as Zacks has maintained a sell on the stock.
EXCO Resources ( XCO) and TransAtlantic Petroleum ( TAT) erased 4.9% and 4.1%, respectively. LDK Solar ( LDK) retreated 3.4% Noble ( NE) decreased 3% as Global Hunter Securities maintains reduce rating on the stock with a price target of $33 per share. The brokerage's 2011 and 2012 EPS estimates of $1.51 and $3.25 are below consensus estimates of $2.04 and $3.97, respectively. Frontline ( FRO) and TransCanada ( TRP) trimmed 3% and 2.9%, respectively. Yingli Green Energy ( YGE) wiped out 2.7% as Avian Securities maintains a negative outlook on the stock with a price target of $8 per share. Also on the downside were Ecopetrol ( EC) and Transocean ( RIG), closing the week in red with a 2% loss.