Jeremy D. Thigpen will resign as senior vice president and CFO of National Oilwell Varco Inc. (NYSE: NOV), the company said April 21. He will become CEO of Transocean Ltd. (NYSE: RIG), the company added.

Thigpen became CFO in 2012. He has been with the company 18 years.

Previously he was president for downhole pumping and solutions from 2007 to 2012. He also had been president of downhole tools group from 2003 to 2007.

The Houston-based multinational oil company will search for a new CFO. Scott K. Duff was appointed interim CFO, effective immediately. He is currently vice president and chief accounting officer at NOV.

Duff joined NOV in 2004, and previously worked in accounting at KPMG, Ernst & Young, and SBC. He has been vice president and chief accounting officer since 2014. Since 2005, he had been vice president of internal audit.

Duff has a bachelor’s of business administration from the University of Texas at San Antonio and is a certified public accountant.