Harold Hamm, the wealthiest energy billionaire in the U.S., became $3 billion richer Wednesday morning when shares of his Continental Resources Inc. rallied as high as $10.58 a share during morning trading in New York, a 22 percent increase. An agreement among the Organization of Petroleum Exporting Countries to cut output sent oil futures and shares of energy companies soaring across the board. Hamm, an energy adviser to President-elect Donald J. Trump, is the world’s 66th richest person on the Bloomberg Billionaires Index with a net worth of $13.8 billion at the close of trading Tuesday.