David J. Mullen is an Irish businessperson who has been the head of 7 different companies and occupies the position of Chairman & Chief Executive Officer for Shelf Drilling (North Sea) Ltd. and Chief Executive Officer & Director at Shelf Drilling Ltd., Chief Executive Officer at Shelf Drilling International Holdings Ltd. and Chief Executive Officer for Shelf Drilling Holdings Ltd. (both are subsidiaries of Shelf Drilling Ltd.). Mr. Mullen is also on the board of Subsea 7 SA and Subsea 7 SA (Luxembourg) and MD & Director-Geco Prakla Personnel Unit at Schlumberger Nigeria Ltd.

David J. Mullen previously occupied the position of Principal at Schlumberger NV and President-South & North America at Schlumberger Oilfield Services, Inc. (a subsidiary of Schlumberger NV), SVP-Global Marketing & Business Development at Transocean Ltd. Chief Executive Officer at Ocean Rig ASA and Senior VP-Global Marketing & Business Development at Transocean, Inc. (both are subsidiaries of Transocean Ltd.) and Chief Executive Officer for Wellstream Holdings Ltd.

He received an undergraduate degree from Trinity College Dublin and a graduate degree from National University of Ireland.