Robert Blanchard, corporate controller and chief accounting officer of National Oilwell Varco, plans to retire July 31, 2014. The company named as his successor Scott Duff.

Duff, who has been with National-Oilwell since 2004, previously held accounting positions at KPMG, Ernst & Young, and SBC before joining National-Oilwell in 2004. Duff has served as National Oilwell Varco's vice president of internal audit since 2005.

National-Oilwell designs, makes, and sells equipment and components used in oil and gas drilling and production operations, the provision of oilfield services, and supply chain integration services to the upstream oil and gas industry.