10. Royal Dutch Shell ( RDS.A) Company profile: Shell is an integrated energy company with exploration, production, and refining operations worldwide. It is of the largest energy companies in the world with refineries and retail operations in the U.S., Europe, and Asia. It's going to be a bellwether in this crisis as it buys oil from Iran. The challenges it faces are as yet unknown, but as one of the biggest suppliers to Western Europe, it's likely to have to buy oil elsewhere to meet its commitments and that could benefit it in terms of higher prices it passes on, as well as some U.S.-based suppliers. Investor takeaway: Shell's shares are up 7% this month and just over 1% on the year. Its shares have a dividend yield of 3.96%. S&P has its shares rated "hold," on expectations of relatively flat earnings this year. S&P's survey of analysts found three "buy/hold" ratings and six "holds." 9. Lukoil ( LKOD) Company profile: Russia's Lukoil, with a $49 billion market value, explores for, produces, refines, transports oil and gas from Western Siberia to markets throughout Western Europe. If Iran shuts off the spigot, or the six European countries that threaten a boycott in July follow through with it, Lukoil will likely be tapped to make up some part of the lost production. Investor takeaway: Its shares are up 12% this month and have a three-year average annual return of 21%. Lukoil doesn't get U.S. investment house coverage, so ratings aren't available. Aberdeen Asset Management is the biggest institutional shareholder with a 2.6% stake. 8. Anadarko Petroleum ( APC) Company profile: Anadarko Petroleum is one of the largest independent oil and gas exploration and production companies in North America and also operates in the Gulf of Mexico and Africa. Investor takeaway: Its shares are up 13% in the past month, and 14% on the year and have a three-year annualized return of 31%. S&P has its shares rated "buy," with a $102 price target, a 15% premium to the current price. Analysts give its shares 14 "buy" ratings, eight "buy/holds," and seven "holds." They expect earnings of $3.48 per share this year and they will grow by 39% in 2013. 7. EOG Resources ( EOG) Company profile: EOG is one of the largest independent oil and gas exploration and production companies in the world, with operations principally in North America, but also in Trinidad, the United Kingdom, and China. Investor takeaway: Its shares are up 14% this month and 19% this year. It is shifting its emphasis from natural gas production to oil to get the better margins oil now offers and that is expected to boost earnings. It is expected to earn $4.59 per share this year, an estimated 30% increase from last year's results. Capital Research Global Investors, with an 8.3% stake, is the largest shareholder. S&P has its shares rated "buy" with a $135 price target, a 17% premium to the current price. Analysts give its shares 10 "buy" ratings, eight "buy/holds," 13 "holds," and one "sell," according to S&P. 6. Hess ( HES) Company profile: Hess is an integrated oil company involved in exploration and production on several continents, with refining and marketing operations primarily in the eastern U.S. The company's downstream operations are comprised of about 1,360 gas stations and a U.S. refinery. Investor takeaway: Its shares are up 15% in the past month, equal to about their gain on the year, including 2.6% in the past week. S&P has its shares rated "buy" with a $76 price target, which is about a 17% premium to the current price. Analysts give its shares eight "buy" ratings, seven "buy/holds," and five "holds." Those same analysts project earnings of $6.61 per share this year and that they will grow by 23% in 2013.