He quickly expanded into the exploration and production of natural gas, then invested in drilling his own oil wells and building pipelines throughout Texas. By the early 1980s, he was one of the state’s wealthiest independent oilmen.
In 2017 he sold his company, Clayton Williams Energy, to Noble Energy for $2.7 billion.
An entrepreneur and philanthropist who founded more than two dozen companies, Mr. Williams had a business portfolio that also included farming, ranching, banking and real estate concerns.
He even dabbled in telecommunications. In 1984, he and his second wife, Modesta (Simpson) Williams, founded the first all-digital long-distance company in Texas, ClayDesta. He starred in his own television commercials, which were filmed on his Alpine ranch.
When proposed legislation threatened the business, he galloped up to the state capitol on a horse to hold a news conference opposing the bill. (The bill died.)
His first marriage, to Betty Meriwether, ended in divorce. He is survived by his wife; three daughters, Kelvie Cleverdon, Allyson Groner and Chicora Wilborn; two sons, Clayton and Jeff Williams; nine grandchildren; five great-grandchildren; and a sister, Janet Pollard.
Mr. Williams was enormously proud of Texas A&M. He flew its flag from his oil rigs around the country and traveled in a jet painted in the school’s colors, maroon and white. He taught at its business school from 1983 to 1989 and served as vice president and director of its Association of Former Students. Over the years, he gave millions of dollars to the university, including $2.5 million for a new alumni center, which bears his name.
When his youngest daughter, Chicora, known as Chim, who was an Aggie, was marrying another Aggie, Mr. Williams attended the wedding wearing an Aggie-maroon tuxedo.
When the minister asked who was giving her away, Mr. Williams replied: “My wife, Modesta, and I — and Texas A&M.”