Any U.S. oil and gas wildcatter looking for a way to get on the Forbes annual Billionaires list might take a hint from some of the interests among those who made this year’s list, published Monday. They like oil and they like natural gas, and many of them especially like shale.

This year’s list of familiar names, is led by No. 1 is Mexico’s Carlos Slim Helu, 73, whose net worth of $73 billion was made from the telecommunications industry. Microsoft founder Bill Gates, 57, with $67 billion is in second place, followed by Spain’s Amancio Ortega, 77, with $57 billion. Berkshire Hathaway Inc.’s Warren Buffett, 82, has $53.5 billion for the No. 4 position, while Oracle Inc.’s Larry Ellison, 68, rounds out the top five with an estimated net worth of $43 billion.

In addition to Buffett, whose subsidiaries often invest in ways to transport oil and gas and keep the lights on, other top U.S. billionaires with heavy investments in the energy sector include Carl Icahn, 77, who was ranked No. 26 with an estimated net worth of $20 billion. The activist shareholder, among other things, helped to change the game at Chesapeake Energy Corp.

In a search on the Forbes website for U.S. billionaires whose wealth is from “energy,” the leader is Continental Resources Inc. founder Harold Hamm, 67, who at No. 90 has an estimated net worth of $11.3 billion, which has grown over the past few years by savvy dealmaking in the Bakken/Three Forks formation.

Rich Kinder, 68, who parlayed his long-ago Enron Corp. stakes into midstream and pipeline giant Kinder Morgan Inc., is ranked No. 112 with an estimated net worth of $9.8 billion. Ray Lee Hunt, 70, heir to the legendary oil man H. L. Hunt, was No. 215 with $5.6 billion net. Self-made billionaire Jeffrey Hildebrand, 54, whose privately held Hilcorp Energy Co. continues to make big deals in big shales, has an estimated net worth of $5.5 billion and is ranked No. 219.

The late Dan Duncan, who founded Enterprise Products Partners LP, and at one time was Houston’s richest — and most charitable — citizen, left enough money in his estate that four of his children share the No. 239 ranking on the Forbes Billionaires list, each with an estimated net worth of $5.1 billion: Dannine Avara, 49; Scott Duncan, 29; Milane Frantz, 43; and Randa Williams, 51, who serves on the Enterprise board.

Other U.S. billionaires who made their fortunes from oil and gas include Chief Oil & Gas founder Trevor Rees-Jones, 61, who with a net worth of $4.5 billion is ranked No. 276. Lynn Schusterman, 74, is ranked No. 384 with a fortune estimated at $3.5 billion that she inherited from her late husband Charles Schusterman’s Samson Investment Co. based in Tulsa.

Terrence Pegula, 62, ranked No. 458, earned his $3 billion fortune by founding East Resources Inc. one of the original Marcellus Shale explorers; East’s Pennsylvania, New York and Rocky Mountain assets were sold to Royal Dutch Shell plc for about $4.7 billion, but East continues to explore for oil and gas in West Virginia.

Energy Transfer Partners LLC CEO Kelcy Warren, 57, is ranked No. 527, with an estimated fortune of $2.7 billion. Lewis Energy founder Rodney Lewis, 58, earned the No. 554 ranking with a net worth of $2.6 billion. George Mitchell, 94, who founded Mitchell Energy and Development Corp. and became the godfather of unconventional drilling, is ranked No. 736 with a net worth of $2 billion.

Energy guru T. Boone Pickens, 85, who continues to preach for the growth of U.S. natural gas and transportation grids, is No. 1,175 on the list with an estimated net worth of $1.2 billion. Also making the list are brothers Dan Wilks, 57, and Farris Wilks, 61, tied at No. 1,258, who each have an estimated net worth of $1.4 billion. The Wilks brothers helped found shale drilling services provider Frac Tech, now FTS International, with Chesapeake Energy Corp. The brothers sold their shares in the company, estimated at about 68%, to a group of investors led by Temasek Holdings for a $3.5 billion payday.

Newcomer Daniel Harrison III earned his No. 1,268 ranking, with a net worth of $1.1 billion, in part by leasing part of his family’s South Texas Harrison Ranch, and with it, the Eagle Ford Shale oil and gas, to a unit of Shell in 2010. Shell also had gained Eagle Ford access through the East Resources purchase. At No. 1,342 is wildcatter William “Tex” Moncrief Jr., 93, who in January 2010 helped to discover the Davy Jones field in the shallow waters of the Gulf of Mexico, which may hold up to 6 Tcf.

Two Canadian oil and gas tycoons made the list. Clayton Riddell, 75, is No. 437 with a net worth of $3.1 billion. Riddell founded natural gas explorer Paramount Resources in 1974 and he also owns stakes in several publicly traded energy companies. Oil mogul N. Murray Edwards, 53, is ranked No. 868 with a net worth of about $1.75 billion. Edwards chairs Canada Natural Resources, which is mining oilsands, and he also chairs Ensign Energy Services.

Also of note is John Arnold, No. 503, whose net worth is estimated at $2.8 billion. The hedge fund billionaire first made his money working as a natural gas trader at Enron Corp., and he parlayed that into forming Centaurus Advisors LLC, which specializes in trading energy products. Arnold, 39, retired from the hedge fund in 2012.

According to Forbes, the 2013 list boasts a total of 1,426 names, with an aggregate net worth of $5.4 trillion, up from $4.6 trillion in 2012. The United States leads with 442 billionaires, followed by Asia-Pacific (386), Europe (366), the Americas (129) and the Middle East and Africa (103).