Mel G. Riggs succeeded Clayton W. Williams Jr. as president of Clayton Williams Energy Inc. (NYSE: CWEI), the company said March 26. Riggs’ role is effective immediately.

Williams is currently chairman and CEO. He said Riggs has more than 30 years’ experience at the company.

Riggs joined the company in 1984. He has been executive vice president and COO since 2010, and previously was senior vice president and CFO.

Midland, Texas-based Clayton Williams Energy Inc. explores and produces domestic oil and natural gas.