A market mauling of oil and gas drilling-exposed stocks due to the Gulf of Mexico's persistent leak and resulting deepwater drilling moratorium has left only a few safe bets to pick out among the remains.

Seadrill, the world's second-largest deepwater driller, is one of those deemed likely to outperform since it has just one Gulf of Mexico rig, and yet it is still trading in line with rival Transocean, which has 14 rigs under contract there this year.

An industry-wide sell-off on Tuesday was prompted by BP’s failure to stop the leak over the weekend. BP was the operator of the Transocean-owned Deepwater Horizon rig that burned and sank.

Other potential safe havens are Schlumberger, the largest oilfield services company with relatively less Gulf of Mexico exposure, and Pride International, which has contracts for its deepwater rigs outside the U.S. region.

"But right now, the baby's going out with the bathwater," said Dan Pickering, oilfield services analyst at Houston-based energy investment boutique Tudor Pickering Holt. "The market's now moved into the territory of saying anything that's bad for the Gulf of Mexico will have repercussions internationally," he added. "There's literally no place to hide."

Yet looking at relative performance, Pickering said Schlumberger faced only a 5% loss from the six-month U.S. deepwater drilling moratorium, while just 15% of its profits are at risk of a complete halt. Shallow-water rig companies may also do better than others, since the moratorium leaves them free to operate.

However, the jackup market was deeply depressed before the Deepwater Horizon sank and the well it drilled sprang a massive leak, casting a pall over the entire offshore oil business. Jackup rig operators such as Rowan Cos and Ensco were hit as hard as the rest of the sector on Tuesday, while Hercules Offshore, which was making losses even before the Horizon sank, tumbled 18%.

Sell-Off Seen Overdone

While determining the ultimate cost of the disaster for the industry will be tricky, most analysts see the market reaction in selling off the sector's companies as overdone. For example, energy consultants at Wood Mackenzie estimate the present value of seven Gulf of Mexico fields threatened by anticipated higher drilling costs at $4.7 billion.

But leaving out the effect of broader U.S. stock market losses, $39 billion has been wiped off the oilfield services benchmark index since April 20, the day of the explosion on the Horizon that led to the spill. About $9 billion of that excess value destruction - or the difference in the losses of the Philadelphia Stock Exchange oil service index and the S&P 500 - stems from the decline in the shares of Transocean, the Horizon's owner.

Underlining the Seadrill case, Barclays Capital on Tuesday initiated coverage of the stock - which only just debuted on the New York Stock Exchange last month, adding to its Oslo listing - with an overweight rating and $27 price target. Analyst James West pointed to its fleet being almost fully contracted through 2011 and its one-rig exposure to the Gulf of Mexico, along with the potential for an improved dividend. But Pickering said a massive exodus of rigs from the Gulf of Mexico would weigh down prices for rigs worldwide.

Big oilfield services firms, which perform more than just exploration-related functions, are seen as better protected than rig contractors. Morgan Stanley has named Baker Hughes, along with Schlumberger and Seadrill, as top picks.

Seadrill shares fell 6.6% to $19.31 in New York on Tuesday, versus a 7.5% sector decline. Schlumberger closed down 7.8%, while Baker Hughes lost 6%. According to Thomson Reuters StarMine, Seadrill trades about in line with Transocean based on share prices over estimated earnings in the next 12 months from StarMine's top-rated analysts.

As of the prior session's close of trade, Transocean and Seadrill both traded above 6 times earnings, while Noble Corp was at 5.4. Diamond Offshore Drilling, despite having a force majeure declared on one of its Gulf of Mexico rigs on Tuesday, is trading at a premium to its peers, at 7.5 times earnings, possibly because the company had already started moving rigs out of U.S. waters in search of better prices for its rigs.