After their recent drubbing, some energy stocks are beginning to look cheap Bloomberg Control manifolds sit near an oil storage tank in Cushing, Okla.Energy stocks have stumbled the most among blue-chip stocks this month, and are headed for another bad quarter after ending the July-September period as the worst-performing sector in the S&P 500. The trouncing of the sector, which is rooted in part in lower oil prices, has rendered some stocks downright cheap, at least as measured by their forward price-to-earnings ratio, a widely used metric that takes into consideration estimated earnings and share prices. The forward p/e is a neat number that gives investors an idea of how cheap a stock is relative to its peers, to an industry group, to the whole market, and so forth. The average for the sector is 13.08 times. The following are five blue-chip energy stocks that have a forward p/e that is well below that average, and what Wall Street has to say about them. Cheap blue-chip energy stocks and their 2014 performanceCompanyForward P/EPerformance YTDNoble Corp.6.3-40%Valero Energy Corp.8-12%Chesapeake Energy Co.10.7-30%ConocoPhillips10.6-3%Chevron Corp.10.7-10%Noble Corp. Driller Noble NE, +2.38% with a forward p/e of 6.3 times, heads the list. Wall Street is lukewarm about Noble, with only four out of 10 analysts covering the company rating it a buy. Still, for those with a medium- to long-term investing horizon, Noble is worth a look — its average price target of $26.17 represents 39% upside from Wednesday’s close. One thing, however: the stock has not performed well lately: shares are off 40% year-to-date.Valero Energy Corp. Refiner Valero VLO, +2.26% has a forward p/e of 8. It has paid investors handsomely in the long-term (shares gained 117% in the past three years, and 65% in 2013) but it hit a rough patch lately — the stock is down 12% so far this year. Six out of 10 analysts covering the company rate the stock a buy, however, and its average price target of $63.77 a share is 46% above Wednesday’s close.Chesapeake Energy Co. Shares of natural-gas producer Chesapeake Energy CHK, +16.99% rallied 15% on Thursday following news that the company is selling acreage and other assets in West Virginia and southwest Pennsylvania to Southwestern Energy Co. for $3.8 billion. Wall Street hopes some of the money will be used to pay down debt and sharpen the company’s focus on oil-rich plays, which are more lucrative. Only 22% of analysts covering the company rate it a buy. The consensus price target of $28.89 representing 63% upside from Wednesday’s close. Chesapeake’s forward p/e is 10.7. Shares have declined 30% so far this year, following gains of 66% in 2013.ConocoPhillips Oil and gas producer ConocoPhillips COP, +1.03% scores more points than the other companies on our list -- nearly 60% of the analysts covering the company rate it a buy. The consensus price target of $90.78 represents 37% upside over Wednesday’s close. Shares have fallen 3% so far this year. ConocoPhillips’ forward p/e is 10.6. Analysts at UBS earlier this month upgraded ConocoPhillips’s stock to neutral, saying shares are fairly valued in relation to peers after a pullback. One of their hang-ups: ConocoPhillips is more exposed to natural gas, which is less profitable than oil, than peers such as Chevron Corp. and Exxon Mobil Corp.Chevron Corp. It doesn’t get any bigger in Big Oil than Chevron CVX, +1.64% an integrated oil and gas producer that has a forward p/e of 10.7. Chevron scores well among the Wall Street types: half of its analysts rate it a buy, and the consensus price target of $135.04 a share represents 24% upside over Wednesday’s close. The stock has been in the weeds this year (down 10% so far) but returned 19% in 2013. Moreover, Chevron has a lower forward p/e than rival Exxon Mobil Corp.XOM, +0.42% which is off 9% this year and returned 20% last year. Exxon’s forward p/e is 12, and the stock has been the most defensive amid the slump — prices are down about 3% in the last two weeks, compared with an average of 10% for the sector. By CLAUDIA ASSIS ENERGY REPORTER