Sep. 7—A Lexington-born oil magnate paid University of Oklahoma students a visit on Wednesday afternoon.

Harold Hamm, founder and chairman of Continental Resources, visited campus to promote his book, "Game Changer," which came out Aug. 1.

All attendees, about 200, took home a free signed copy of his book.

Hamm is a pioneer in horizontal drilling, which in turn with hydraulic fracturing, paved a way that would revolutionize how oil is extracted throughout the world.

According to Forbes, Hamm is currently the 81st wealthiest person on Earth and is worth $20.2 billion.

"It totally changed the game," Hamm said at the Beaird Lounge of Memorial Union.

He compared the importance of horizontal drilling to the advent of FedEx, or other game-changing businesses.

"That completely changes everything, and horizontal drilling changed it all. It gave us access to all the reservoirs that contained oil that was too tight to produce," he said.

OU President Joe Harroz Jr. said more than 200 former OU students currently work at Continental Resources.

"There are students in the audience here who I know hope to become part of that 200. There are also recruiters from Continental," Harroz said.

Harroz said the oil industry is essential to life at the university.

"In every area across the institution you see oil and gas embedded in our DNA," said Harroz. "Oil and gas is truly a part of who we are."

Harroz, who said he read the book twice before the event, sat down with Hamm in a fireside chat-style conversation.

Harroz said the book is "not some love story to oil and gas."

"It's a discussion about our national energy strategy and the implications of that for the U.S. and for the world. And it tells us lessons of the past to project towards the future and into real questions in real time," he said.

Hamm said horizontal drilling changed the game because of fracking.

"That gave us access to the shales. Who thought we could produce oil from the shales?" Hamm said. "We could. We went from nobody doing it to everybody drilling horizontally."

Hamm took shots at former President Jimmy Carter for having supported legislation that created incentives for renewable energy and coal while banning new power plants that used gas or oil.

"Carter had basically declared war on energy. As you recall, that one thing they passed was a mandate of 100% use of coal and power plants for power generation," Hamm said.

President Ronald Reagan repealed the law in 1987.

Hamm said he consulted with George H. W. Bush on energy policy, and he became the energy advisor to former Republican nominee Mitt Romney.

He criticized President Richard Nixon for banning the exportation of oil and shared the story of how he helped repeal the law by placing an earmark in the 2015 omnibus bill during President Barack Obama's administration.

"And certainly in the Nixon days, they developed this era of scarcity, and we had to tend to hoard supplies of oil, so they banned the export of oil," Hamm said. "It's kind of the dumbest thing you could do — block trade like that — but they did, and it hung around for 40 years."

He said the development of shale through horizontal drilling increased energy stores, which contributed to the change in law.

"We had a president who was not going to pass the thing, but we had to try," he said. "We put it in an omnibus spending bill. There is nothing they would rather do in Congress in Washington D.C. than spend money, so we got it done."

Harroz said changing the law to allow oil exports has been important since Russia invaded Ukraine.

"The ability to export our energy played a critical role that was not available for 40 years until 2015," he said. "You have to ask the question, how much longer could Western Europe and Central Europe have stood up to Russia? and what would have happened to the Ukraine and therefore what would have happened to democracies worldwide?"

He said he would like to see every student at OU read the book.