Board of Directors

Clay C. Williams
National Oilwell Varco
Chairman, President and Chief Executive Officer
Clay Williams is the Chairman, President, and Chief Executive Officer of National Oilwell Varco (NOV). Previously, he served as NOV’s President and Chief Operating Officer and its Executive Vice President and Chief Financial Officer. Prior to its merger with National Oilwell, Clay served as Varco’s Chief Financial Officer. He also served as Vice President of Finance, Vice President of Corporate Development, and Vice President of Pipeline Services for Varco and Tuboscope before the merger between the two companies. Before Tuboscope, he worked for SCF Partners and Shell Oil Company. Clay also currently serves as a director of Benchmark Electronics, Inc. Clay has a Bachelor of Science in Civil and Geological Engineering from Princeton University and holds a Master’s of Business Administration from the University of Texas.

Greg L. Armstrong
Plains All American GP LLC
Lead Director
Mr. Armstrong has been a Director of the Company since March 2005. Mr. Armstrong served as a Director of Varco from May 20, 2004 until its merger with the Company on March 11, 2005. Since 1998, he has been the Chairman of the Board and Chief Executive Officer of Plains All American GP LLC, the general partner and controlling entity of Plains All American Pipeline, L.P., a publicly traded master limited partnership engaged in the business of marketing, gathering, transporting, terminalling and storing crude oil. Mr. Armstrong also serves as a director of the Independent Petroleum Association of America Southwest Texas Region and is a member of the National Petroleum Council.

Marcela E. Donadio
Director
Ms. Donadio has been a Director of the Company since April 2014. Ms. Donadio has over 37 years of audit and public accounting experience with a specialization in domestic and international operations in all segments of the energy industry. She was Americas Oil & Gas Sector Leader of Ernst & Young LLP, from which she retired in March 2014. Ms. Donadio joined Ernst & Young in 1976, serving since 1989 as audit partner for multiple companies in the oil and gas industry. She held various energy industry leadership positions until being named Americas Oil & Gas Sector Leader in 2007. In that role she was responsible for one of the firm's most significant industry groups in the US and throughout the Americas. Ms. Donadio earned a Bachelor of Science degree in Accounting from Louisiana State University and is a licensed certified public accountant in the State of Texas.

Ben A. Guill
White Deer Energy
Director
Mr. Guill has been a Director of the Company since 1999. Since 2010, Mr. Guill has been a founding Partner of White Deer Energy, a private equity fund focused on the exploration & production, oilfield service and equipment, and midstream sectors of the oil and gas industry. Until April 2007, he was President of First Reserve Corporation, a corporate manager of private investments focusing on the energy and energy-related sectors, which he joined in September 1998. Prior to joining First Reserve, Mr. Guill was the Managing Director and Co-head of Investment Banking of Simmons & Company International, an investment-banking firm specializing in the oil service industry.

James T. "Jim" Hackett
Alta Mesa Resources
Director
Mr. Hackett has been a Director of the Company since April 2016. Mr. Hackett is currently serving as the Executive Chairman of Alta Mesa Resources and Chief Operating Officer of Kingfisher Midstream, a wholly owned affiliate of Alta Mesa Resources focused on gathering, processing, marketing and transportation of hydrocarbons. Mr. Hackett is also a Partner at Riverstone Holdings, LLC, an energy focused private investment firm, based in New York, which he joined in 2013. Prior to joining Riverstone Holdings, LLC in 2013, Mr. Hackett served as the Chairman of the Board from 2006 to 2013 and the CEO from 2003 to 2012 of Anadarko Petroleum Corporation. Before joining Anadarko, Mr. Hackett served as President and Chief Operating Officer of Devon Energy Corporation, following its merger with Ocean Energy, where he had served as Chairman, President, and Chief Executive Officer. Mr. Hackett has also held senior positions at Seagull, Duke Energy, and Pan Energy. He also held positions in engineering, finance and marketing with NGC Corp., Burlington Resources, and Amoco Oil Corp. Mr. Hackett received a Bachelor of Science degree from the University of Illinois in 1975 and an MBA from Harvard Business School in 1979.

David D. Harrison
Director
Mr. Harrison has been a Director of the Company since August 2003. He has served as Executive Vice President and Chief Financial Officer of Pentair, Inc., a diversified manufacturer in water technologies and enclosures businesses since February 2000 until his retirement in February 2007. From September 1999 through February 2000, Mr. Harrison was Executive Vice President and Chief Financial Officer of the Scotts Company, a lawn and garden products company. He was Executive Vice President and Chief Financial Officer and a Director of Coltec Industries, a company in the industrial and aerospace arena from 1996 to 1999. He also served as Executive Vice President and Chief Financial Officer of Pentair, Inc. from 1994 to 1996.

Eric L. Mattson
Director
Mr. Mattson has been a Director of the Company since March 2005. Mr. Mattson served as a Director of Varco (and its predecessor, Tuboscope Inc.) from January 1994 until its merger with the Company on March 11, 2005. Mr. Mattson was the EVP-Finance of Select Energy Services, Inc., a public oil service company located in Houston, from which he retired in March 2018. Prior to that, Mr. Mattson served as Senior Vice President and Chief Financial Officer of VeriCenter, Inc., a private provider of managed hosting services, since 2003, until its acquisition in August 2007. From November 2002 until October 2003, Mr. Mattson worked as an independent consultant. Mr. Mattson was the Chief Financial Officer of Netrail, Inc., a private Internet backbone and broadband service provider, from September 1999 until November 2002. From July 1993 until May 1999, Mr. Mattson served as Senior Vice President and Chief Financial Officer of Baker Hughes Incorporated, a provider of products and services to the oil, gas and process industries.

Melody B. Meyer
Director
Ms. Meyer has been a Director of the Company since September 2017. Ms. Meyer was with Chevron for over 37 years and held various positions of increasing responsibility, including managing domestic and international operations, managing strategy and planning and leading new technology development for the organization. Ms. Meyer was the President of Chevron Asia Pacific Exploration and Production from 2011 until her retirement in 2016. Prior to that, Ms. Meyer served as the President of the Chevron Energy Technology Company from 2008 to 2011 and the Vice President of Chevron’s Gulf of Mexico business unit from 2004 to 2008. Ms. Meyer received a Bachelor of Science in Mechanical Engineering from Trinity University in 1979. Additionally, Ms. Meyer attended the Dartmouth Tuck Executive Education Program in 1997.

William R. Thomas
EOG Resources, Inc.
Director
Mr. Thomas has been a Director of the Company since November 2015. Mr. Thomas has been serving as the Chairman and CEO of EOG Resources, Inc. since January 2014. Prior to that, he served as President and CEO from July 2013 through December 2013 and as President from September 2011 to July 2013. Mr. Thomas previously held other leadership positions at EOG Resources, Inc., including Senior Executive Vice President, Exploitation and Senior Executive Vice President, Exploration. Mr. Thomas has been with EOG Resources, Inc. and its predecessor companies since 1979. Mr. Thomas received a Bachelor of Science degree in Geology from Texas A&M University in 1975.