The Association is governed by its Board of Directors, comprised of employees of Drilling Contractor member companies who are elected annually. Responsibilities include confirming annual appointment of IADC’s Officers, reviewing significant organizational changes, and approving annual budget.

The Executive Committee consists of up to 21 Directors and leads the overall direction of the Association, including objectives, structure and operations, making recommendations to the Board of Directors as needed.

Advisory Panels are formed to evaluate issues affecting Members and report those issues to the Executive Committee for consideration and action.

IADC Officers & Executive Committee


Julie RobertsonR. H. “BOB” GEDDES, CHAIR

Ensign Energy Services

Mr. Geddes has been with Ensign since 1991 and is currently the President and Chief Operating Officer of the Corporation, a position he has held since 2007. He has acted as Vice President Canadian Drilling from 1999 to 2004 and President Canadian Operations from 2004 to 2006.

He is a past Chairman of the Canadian Association of Oilwell Drilling Contractors (CAODC), and is a member of the Association of Professional Engineers and Geoscientists of Alberta (APEGA). He holds a B.Sc. in Mechanical Engineering from the University of Alberta.


Transocean, Ltd.

Mr. Thigpen joined Transocean as the company’s CEO in April 2015. He previously served as Senior Vice President and Chief Financial Officer at National Oilwell Varco, where he spent 18 years. During his tenure at NOV, Mr. Thigpen spent five years as the company’s President of Downhole and Pumping Solutions business and four years as President of its Downhole Tools group. He also served in various management and business development capacities, including Director of Business Development and Special Assistant to the Chairman. Mr. Thigpen earned his Bachelor of Arts in Economics and Managerial Studies from Rice University and completed the Program for Management Development at Harvard Business School.


Northern Ocean Ltd.

Mr. Scott McReaken was appointed Chief Executive Officer of the Northern Drilling and Northern Ocean Groups in December 2018. Prior to this appointment Mr. McReaken has been a part of the Seadrill group companies since 2012, where he served as Chief Executive Officer and Director of Sevan Drilling Ltd and Chief Financial Officer of North Atlantic Drilling Ltd.

Mr. McReaken has almost 20 years of experience in the offshore drilling industry, which includes various leadership roles in the United States, North Sea, West Africa and South America. Mr. McReaken began his career at Arthur Andersen LLP and is a Certified Public Accountant and Certified Internal Auditor.

He holds a degree in business administration from The University of Texas at Austin and is a US citizen residing in Houston, Texas.



Robin Macmillan, LLC

Robin Macmillan attained a degree in Geology from the University of Leeds in England and started his oilfield career many years ago drilling in the Rio Grande Valley.

Since then Robin has worked both offshore and onshore in many countries, including eight years in Latin America. Having joined drill bit company ReedHycalog in 1991, Robin worked in several sales and management positions including the management of Schlumberger Drilling and Measurements in Canada. Robin was appointed as President of ReedHycalog in 2008 and then Senior Vice President for Business Development at National Oilwell Varco. He currently works as an independent consultant.

Robin has technical publications on drilling automation, drill bit design, managed pressure drilling, high-speed downhole telemetry and digitalization of daily drilling reports. He also holds a patent on drill bit design.

He is chair emeritus of the IADC Advanced Rig Technology committee, vice chair of the SPE Drilling Systems Automation Technical Section and a member of the IADC Drilling Engineers Committee.


Cactus Drilling Company

Scott McKee is the Vice President for Marketing at Cactus Drilling Company in Oklahoma City. He began his oilfield career in 2004 and is a past Chairman of the IADC Oklahoma/Texas Panhandle Chapter. Scott is a West Point graduate and left active duty as a combat veteran and Army Captain. He is a member of the American Association of Drilling Engineers and serves on the Board at Twin Hills Golf & Country Club in OKC. He is a member of Henderson Hills Church in Edmond, OK.


Noble Corporation

Mr. Woodward is the Vice President of Corporate Services at Noble Corporation. In this capacity he manages the company’s Human Resources, Information Technology, Supply Chain, and HSE functions. Mr. Woodward previously served as Noble’s Global Operations Manager and has held various domestic and international roles in Operations, Marketing, Investor Relations, Human Resources, and HSE since joining the company in 2002. In addition to his role as IADC Division Vice President Offshore, he serves on various committees for both IADC and SPE.

Mr. Woodward graduated with a BBA in Management from The University of Texas at Austin and received an MBA in Oil and Gas Management from Robert Gordon University in Aberdeen.



Jim Tolsma has 30 years of industry experience with a number of drilling and oilfield service companies. He has been a member of the IADC International Onshore Advisory Panel (IOnAP) since 2018. In this capacity, he has participated in discussions on various topics related to international land drilling. He has a BS degree in Engineering from the United States Military Academy at West Point and a MBA from Texas A&M University.

2021 Executive Committee

  • ANTHONY GALLEGOS, Independence Contract Drilling, Houston, Texas
  • BERNIE WOLFORD, Pacific Drilling, Houston, Texas
  • BRIAN WOODWARD, Noble Corporation plc, Sugar Land, Texas
  • BRAD JAMES, Enterprise Offshore Drilling, Houston, Texas
  • GENE STAHL, Precision Drilling Corporation, Houston, Texas
  • IHAB TOMA, Vantage Drilling, Dubai, UAE
  • KEVIN NEVEU, Precision Drilling Corporation, Houston, Texas
  • JEREMY THIGPEN, Transocean, Vernier, Switzerland
  • JIM TOLSMA, Houston, Texas
  • JØRN MADSEN, Maersk Drilling, Copenhagen, Denmark
  • LEIF NELSON, Seadrill, London, UK
  • MANAV KUMAR, Dynamic Drilling, Dubai, UAE/Singapore
  • MIKE HOLCOMB, Patterson-UTI Energy Inc., Houston, Texas
  • MIKE NUSS, Ensign Energy Services, Houston, Texas
  • PAUL MOSVOLD, Scandrill, Inc., Houston, Texas
  • ROBERT H. “BOB” GEDDES, Ensign Energy Services, Calgary, AB, Canada
  • ROBIN MACMILLAN, Robin Macmillan LLC, Houston, Texas
  • SCOTT MCKEE, Cactus Drilling Company, Oklahoma City, Oklahoma
  • SCOTT MCREAKEN, Northern Drilling Ltd., Houston, Texas
  • SHANE MARCHAND, Helmerich & Payne Inc., Tulsa, Oklahoma