Our Leadership

Driving us forward

Our leadership is comprised of dedicated, honest, and inspiring individuals.

Together, they are responsible for leading Weatherford to new heights.

Mark A. McCollum

President and Chief Executive Officer, Weatherford International plc

Mr. Mark McCollum is President and Chief Executive Officer for Weatherford International plc. Weatherford is one of the largest multinational oilfield service companies providing innovative solutions, technology, and services to the oil and gas industry. The Company operates in over 80 countries and has a network of approximately 700 locations, including manufacturing, service, research and development, and training facilities and employs approximately 26,500 people.

Prior to joining Weatherford, Mr. McCollum served as Executive Vice President and Chief Financial Officer for Halliburton. Mr. McCollum also served as Senior Vice President and Chief Accounting Officer for Halliburton from 2003 to 2007.

Prior to joining Halliburton, Mr. McCollum served in various senior executive positions for Tenneco from 1995 through 2003. Before joining Tenneco, Mr. McCollum spent 14 years with Arthur Andersen LLP and served as an Audit and Business Advisory Partner of the firm’s worldwide partnership from 1991 through 1994. He earned a BBA in 1980 from Baylor University.

Mr. McCollum serves on the Board of Directors for Westlake Chemical Corporation. He is a member of the Board of Regents of Baylor University, and he also serves on the Board of Trustees for Baylor College of Medicine and the Advisory Board of Every Village.

Karl Blanchard

Executive Vice President and Chief Operating Officer

Karl Blanchard is the Executive Vice President and Chief Operating Officer of Weatherford. He assumed this position in August 2017. In his role at Weatherford, Karl oversees all region and product line operations, QHSE, sales, engineering, R&D, and supply chain.

Karl brings with him a career of significant achievement and valuable insight gained from more than 35 years in the oil and gas service industry. He served as Chief Operating Officer for Seventy Seven Energy where he was responsible for the drilling, hydraulic fracturing, and rental tool business units, as well as key support functions. As part of Seventy Seven’s leadership team, he successfully transitioned the company into a stand-alone publically traded company, executed cost management initiatives, and implemented a structured process focused on developing in-house leadership talent. These accomplishments resulted in Seventy Seven’s successful merger with Patterson-UTI, creating the second largest land driller and top five pressure pumping company in the United States.

Prior to Seventy Seven Energy, Karl spent more than 30 years at Halliburton where he was responsible for a significant portion of the company’s flagship product service lines, including production enhancement, cementing, and testing and subsea. He also served as Country Vice President of Halliburton Indonesia.

Karl has a Bachelor of Science degree in engineering from Texas A&M University and is a member of the Society of Petroleum Engineers.

Steven F. Carvalho

Vice President of Tax

Steven “Steve” Carvalho is the Vice President of Tax. He is responsible for all areas of tax, including global tax planning and compliance.

Steve began his tenure at Weatherford at the beginning of 2013 as the Assistant Vice President of Tax Operations, and was promoted to Vice President of Tax in 2018. During his tenure at Weatherford, he built the Company’s tax operations group from the ground up and led its remediation efforts to address material weakness in tax.

From 2002 to 2012, Steve performed several roles at PricewaterhouseCoopers including Consultant, Manager, and finally, Tax Director. He started his career with Arthur Andersen LLP. While in consulting, Steve served a full spectrum of clients from large multinational corporations to startup technology and life science companies. He has over 20 years’ experience in multinational taxation for large public companies in the areas of tax planning, tax compliance, and tax accounting.

Steve graduated from the University of Rhode Island with a degree in Accounting, and from Suffolk University Law School with a Law degree. He is admitted to the Bar in the Commonwealth of Massachusetts and is a member of the Massachusetts Bar Association.

He is married with three boys. In addition to spending time with his family, Steve enjoys running, hiking and other outdoor activities.

Ellen Chin

Senior Vice President & Chief Human Resource Officer

In this role, Ellen leads the global human resources function across all geozones and global product lines in addition to all corporate functions. Ellen is a member of the Diverse and Inclusive Committee where she helps ensure a talent management culture that provides our employees with the opportunity to bring their true selves to work.

Ellen joined Weatherford in 2012 and has held various roles in Human Resources, including Vice President of Human Resources for the Western Hemisphere.

Ellen is a business-minded professional with more than 25 years of executive leadership experience. Before Weatherford, Ellen served as the Global Director of Compensation, Benefits, Talent Management and HR Systems at Ascend Performance Materials. She was also the Western Hemisphere Director of Compensation and Benefits at Baker Hughes. She started her career in various consulting roles at AonHewitt and TowersWatson, assisting clients with HR transformations, developing Total Rewards strategies, and implementing state-of-the-art HR technologies and communications solutions.

Ellen holds a Bachelor of Business Administration degree in Management Information Systems from the McCombs School of Business at the University of Texas at Austin. She is married with three teenagers.

Karen David-Green

Senior Vice President, Stakeholder Engagement and Chief Marketing Officer

Karen David-Green currently serves as the Senior Vice President, Stakeholder Engagement and Chief Marketing Officer. In this role, she is responsible for all aspects of marketing and communications, including brand management, public relations, external and employee communications, digital strategy, and stakeholder and community relations for the Company’s broad global infrastructure spanning more than 80 countries and 26,000 employees. Alongside her executive duties, she is a member of the Disclosure Committee and the Diversity and Inclusion, and Sustainability committees, which help to progress the Company’s commitment to a healthy culture and sustainability agenda.

Since joining the Company in 2010, Karen has been the strategic leader of the Company’s messaging strategy, including financial communications and media relations, crisis communications, digital/social communications, and thought leadership across all channels. She was instrumental in redefining and launching the Company’s mission statement and core values, and activated campaigns, such as ‘One Weatherford’, to shift the culture, improve morale and drive and shape employee engagement.

Prior to working at Weatherford, Karen held senior executive roles at notable Wall Street firms, including Oppenheimer & Co. Inc., Calyon Securities (USA), RBC Dominion Securities, and Jefferies & Company. She focused on providing equity research of the oil service and equipment energy industry and interfaced with global institutional shareholders to provide investment recommendations. In addition, she managed a multi-billion dollar fixed income chemical portfolio and oversaw both investment-grade and high-yield investment allocation and analysis. Karen received her Bachelor of Business Administration from the University of Texas at Austin where she majored in Finance.

Karen’s contributions extend beyond her business organizations to her community. She curently serves on the Board of Directors of Small Steps Nurturing Center, a non-profit organization dedicated to the social, emotional, physical, intellectual and spiritual growth of economically at-risk children and their families. She also serves on the Board of Directors of the Greater Houston Women's Chamber of Commerce and is a member of the IPAA/PESA Education Advisory Board. She is a former board member of the Young Women’s College Preparatory Academy and a former advisory board member of The Women’s Fund.

Dedication both at work and in the community has led Karen to receive numerous distinguished awards throughout her career. Recognition includes the 2019 Women Who Mean Business Honoree from the Houston Business Journal, Breakthrough Woman of the Year Award in 2019 from the Greater Houston Women’s Chamber of Commerce, the Crystal Award for Best Product Launch Marketing Campaign in 2018 from the American Marketing Association and the Stevie International Business Award for Best Online Annual Report in 2015 and 2016 – which drew competition from worldwide organizations of different sizes in both public and private domains in more than 60 countries.

Stuart Fraser

Vice President, Chief Accounting Officer

Stuart Fraser is the Vice President, Chief Accounting Officer at Weatherford.

In this role, Stuart oversees the accounting and financial reporting functions for the Company and has been responsible for supporting the recent capital market transactions to reduce the debt ratio and streamline the cost structure in one of the most challenging markets in recent history.

Stuart joined Weatherford in 2015 and has served in various senior financial roles including Vice President and Corporate Controller and Vice President of Finance and Purchasing, Sourcing and Logistics. Before his role at Weatherford, he served a 19-year career with Schlumberger Ltd., where he held senior financial positions in global and regional capacities in the US, France, Angola, Malaysia, and Indonesia across a number of business segments covering operations, internal audit, taxation, supply chain, and transformation.

Stuart is a Chartered Accountant and holds a Bachelor of Business degree from the Edith Cowan University in Australia.

Christian A. Garcia

Executive Vice President and Chief Financial Officer

Christian A. Garcia is currently Executive Vice President and Chief Financial Officer of Weatherford International where he leads all financial activities, including accounting, treasury, tax, internal audit and investor relations. He also oversees corporate development and information technology.  Mr. Garcia has more than 30 years of leadership experience in the oilfield services, automotive electronics, software and consulting, and business equipment industries.

Prior to joining Weatherford, Mr. Garcia served in multiple executive roles including Executive Vice President and Chief Financial Officer of Visteon, a leader in automotive cockpit electronics, and acting Chief Financial Officer of Halliburton, an oilfield services company.  At Halliburton, he progressed through a variety of leadership positions including Chief Accounting Officer, Treasurer, and Senior Vice President of Investor Relations.  Earlier in his career, he held financial and planning roles with Landmark Graphics, Bell and Howell, and San Miguel Corporation in the Philippines.  Mr. Garcia served as board member and chairman of the audit committee for Keane Group from 2017 to 2019.

Mr. Garcia has been consistently selected to the All-America Executive Team by Institutional Investor magazine.  In 2011, he was awarded “IR Professional of the Year” given to the top investor relations professional in the United States based on the magazine’s survey of more than 1,300 security analysts and investment professionals.

Mr. Garcia has a bachelor's degree in business economics from the University of the Philippines, and a master's degree in management from Purdue University.  

Christina M. Ibrahim

Executive Vice President, General Counsel, Chief Compliance Officer, and Corporate Secretary

Christina M. Ibrahim was appointed Executive Vice President, General Counsel, Chief Compliance Officer and Secretary of Weatherford International in May 2015. Ms. Ibrahim has over 20 years of legal experience primarily in the oilfield services industry. Prior to her appointment at Weatherford, Ms. Ibrahim held several senior leadership positions in the legal department of Halliburton Company, including Vice President, Corporate Secretary and Global Chief Commercial Counsel, with additional responsibility for the global Procurement, Employment and Real Estate practice groups and oversight of the mergers and acquisitions, securities, regulatory and governance functions. Ms. Ibrahim also served as General Counsel and Chief Compliance Officer for WellDynamics, a Halliburton and Shell joint venture company. Prior to joining Halliburton, Ms. Ibrahim was a litigation attorney with the law firm Wickliff & Hall, PC.

Ms. Ibrahim earned a Bachelor of Science in Business Management from Virginia Tech and a Juris Doctorate from Texas Southern University where she graduated magna cum laude. She is a member of the Texas State Bar, Women Corporate Directors and the National Association of Corporate Directors.

Ms. Ibrahim is a Director of PDC Energy, Inc., Denver, Colorado and serves as the Chair of its Nominating and Governance Committee. Additionally, she on the Executive Leadership Team of the Go Red, an American Heart Association Campaign. She is a frequent speaker and panelist on many topics, including corporate governance, international commercial agreements, ethics, diversity, compliance and leadership.

She is currently a proud supporter and member of the National Association of Corporate Directors, Texas State Bar, Texas General Counsel Forum, American Bar Association, Women’s Energy Network, the Society of Corporate Compliance and Ethics, and the Society for Corporate Governance. Christina also serves on several local not-for-profit boards including the Houston Area Women's Center.

Christina has received numerous awards for her leadership and achievements. Her most recent recognition includes Texas Lawyer, GC Impact honoree, 2019, and featured in Modern Counsel. Additionally, she received Women Who Mean Business Award, from the Houston Business Journal (2018), Legal Department of the Year, Corporate Compliance, from Texas Lawyer (2017), Breakthrough Woman from the Greater Houston Women’s Chamber of Commerce (2016), Women in Energy Leadership honoree from Houston Business Journal (2015), Influential Woman Leadership Award from National Diversity Council (2014), and Top In-House Lawyers in the United States from Corporate Counsel 100 (2013).

Frederico Justus

President Eastern Hemisphere

He is responsible for Weatherford’s Eastern Hemisphere operations and also serves on the Sustainability Committee, helping to provide a diverse perspective of sustainability needs across the organization.

Frederico joined Weatherford in 2010 and has held various positions including Vice President roles for Continental Europe, Europe and Caspian, Sub-Sahara Africa, and Middle East and North Africa.

In his more than 18 years experience in the oil and gas industry, he has worked all over the globe. Prior to joining Weatherford, Frederico spent 12 years working for Schlumberger in various management assignments.

Early in his career with Weatherford, Frederico was responsible for three different regions – Europe, Sub-Sahara Africa (SSA), and the Middle East – where he led substantial enhancements, including several integrated projects in Europe and several high-profile managed pressure drilling projects in offshore Angola. Under his leadership, Weatherford gained positive offshore market share distribution in the West Coast of SSA, won the biggest wireline contract ever executed in Kuwait, and also reduced non-productive time in the complex Saudi Arabia market by 50%.

Frederico graduated with a Mechanical Engineering degree with specializations in Strategic Marketing at Stanford University and an Integrated Reservoir Management degree from the Institute of Petroleum and Imperial College, London.