An Oklahoma oil tycoon and key player in America's recent oil boom may soon face the largest divorce judgment ever.
Last week lawyers for Harold Hamm and his wife Sue Ann Hamm squared off in divorce court in Oklahoma City, according to court documents.
Not much is known about the trial -- the judge has sealed most records and the proceedings. But Mr. Hamm, 68, is worth an estimated $20.2 billion, according to the research firm WealthX. The vast majority of that wealth was accrued during his 26-year marriage.
Mrs. Hamm, 58, would only need to get a quarter of his net worth to surpass the $4.5 billion judgment against Russian oligarch Dmitry Rybolovlev in May. That ruling was dubbed the "most expensive divorce in history" at the time.
But now the Hamm divorce is poised to top that. "It appears it will be the most expensive divorce in history," said Seymour Reisman, a matrimonial attorney in New York who handles high net worth cases, although he's not involved in the Hamm trial. "I saw one report saying she was in line for $4 billion to $8 billion."
Mr. Hamm, no. 39 on Forbes' list of the world's richest people, made his money as founder and chairman of Continental Resources (, an oil company that helped pioneer the use of fracking. Hamm also was Mitt Romney's top energy adviser during the 2012 presidential campaign, and was named as one of Time Magazine's most influential people that year. )
The judge ordered the case closed out of concern the trial could reveal sensitive information about Continental, one of the largest producers in North Dakota's Bakken Shale. The judge said he set aside eight weeks for the trial, according to the Daily Oklahoman.
How the Hamms' assets will be split depends on two central issues, said M. Shane Henry, an Oklahoma matrimonial attorney who is not directly involved in the trial but is following it through press reports and chatter in the local legal community.
The first is the date to be used for the separation of assets, said Henry, chair of the Oklahoma Bar Association's family law section. The earlier the date used, the more likely Mr. Hamm will get to keep a larger share of the fortune, since Continental's value has grown tremendously over the last few years.
The second is how much Mrs. Hamm contributed to the growth of the company, both as a former executive at Continental and as a partner to Mr. Hamm. Mr. Hamm owned the majority of Continental shares before his marriage to Mrs. Hamm.
In most divorce cases, the parties settle, but "the reason these people can't settle is it means literally millions and millions of dollars to one side or the other," Henry said.
Another complication is that there reportedly is no prenuptial agreement, according to Reuters, though Reisman in New York said that still wouldn't rule out a large judgment.
"Prenuptials are like any contract," he said. "Lawyers can find loopholes to set them aside."
Lawyers for neither Mr. Hamm nor Mrs. Hamm returned calls seeking comment.
Mr. Hamm is a somewhat larger-than-life figure in an industry known for them -- a self-made "wildcatter," or someone who drills for oil where it hasn't previously been found.
Born the last of 13 children to a family of Oklahoma sharecroppers, he started driving tank trucks for the oil industry right out of high school. He started his businesses by buying trucks, then other oil field equipment, and finally oil wells -- all before receiving a formal college education.
"It's been a tremendous ride," he told CNNMoney in a 2011 interview. "And it's all been built through the bit."