James M. Trimble was elected as interim CEO and president of Stone Energy Corp. (NYSE: SGY) by the board of directors, as David H. Welch will retire as CEO and president after more than 13 years at the company, Stone Energy said April 28.

Welch will also step down from his position as a company director.

Trimble’s election is effective immediately. He is an independent director.

Trimble was president and CEO of PDC Energy (NASDAQ: PDCE) from 2011 to 2015. Previously, he founded and/or led several private oil and gas companies focused drilling in Texas, Louisiana and Oklahoma, the press release said. Trimble also was senior vice president of E&P for Cabot Oil and Gas Corp. (NYSE: COG) for 17 years. Overall, he has more than 35 years of energy industry experience, the press release said.

He earned a degree from Mississippi State University.

The board also appointed Keith Seilhan to the new position of COO, effective immediately, the company said, adding that Seilhan was formerly the senior vice president for Gulf of Mexico.

Prior to joining Stone Energy, Seilhan worked for 21 years at Amoco and BP Plc (NYSE: BP), working in various senior leadership and operations roles.

At Stone Energy, he was deepwater projects manager beginning in July 2012, and became vice president of deepwater in February 2013 and senior vice president of Gulf of Mexico in January 2015.

Stone Energy Corp. is based in Lafayette, La.