Tony Petrello was elected to the Nabors Board of Directors and the Executive Committee of the Board in 1991. He has served as our President and Chief Operating Officer from 1991 to October 2011, Deputy Chairman since 2003, President and Chief Executive Officer since October 2011, and Chairman of the Board and Chairman of the Executive Committee of the Board since June 2012. In addition to his operating functions, Petrello provides strategic planning initiative and direction enabling the Company to adapt and prosper in our dynamic competitive environment.
Prior to joining Nabors, from 1979 to 1991, Petrello was with the law firm Baker & McKenzie, where his practice focused on international arbitration, taxation and general corporate law. He served as Managing Partner of the firm’s New York office from 1986 until his resignation in 1991. Petrello holds a J.D. degree from Harvard Law School and B.S. and M.S. degrees in Mathematics from Yale University.
He serves as a director of Stewart & Stevenson LLC and of Hilcorp Energy Company. Petrello is also a member of the Board of Trustees of Texas Children's Hospital and an advocate for research and clinical programs to address the needs of children with neurological disorders.
William Restrepo serves as Chief Financial Officer of Nabors. In this role, Restrepo has oversight for global finance and accounting as well as the treasury, tax, risk management and internal audit groups. He also works closely on Nabors’ corporate development and investor relations initiatives.
Restrepo has an extensive portfolio of proven domestic and international capabilities in corporate finance, financial accounting, internal audit, tax, operations, and mergers and acquisitions, as well as planning and analysis.
Prior to joining Nabors in March 2014, Restrepo served as CFO at Pacific Drilling. He also previously served as CFO at Seitel and at Smith International until its acquisition by Schlumberger. Prior to that, Restrepo spent 20 years with Schlumberger in various senior financial and operational positions, including operational responsibility for all product lines in the Continental Europe and the Arabian Gulf markets, as well as senior financial executive roles in Corporate Treasury and worldwide controller positions with international postings in Europe, South America and Asia.
Restrepo holds bachelor's degrees in economics and civil engineering, respectively, from Cornell University and the University of Miami. He also earned an MBA from Cornell University.
Mark Andrews serves as the Corporate Secretary for Nabors, a position he has held since joining the company in 2007, and is responsible for coordinating meetings and communication with the Board.
Prior to joining Nabors, Andrews served in various treasury and financial management positions with General Electric Company. Prior to that, he was a Tax Manager within the mining and resource practice of PricewaterhouseCoopers LLP.
Andrews holds an Honours B.B.A. degree from Wilfrid Laurier University, is a Chartered Accountant and a CFA charterholder.
Carina Lovato Gillenwater directs human resources activities worldwide.
Gillenwater joined Nabors in August 2012. Prior to joining Nabors, she served as Vice President of Human Resources for Schlumberger’s North American Drilling Group. Before joining Schlumberger, she served as Global Vice President for recruiting, compensation and benefits, training and development for Smith International. Gillenwater began her career in oil and gas in Brazil working for Bombas Geremia, LTDA., a company that was subsequently acquired by Weatherford International.
She obtained her B.A. degree in Language and Literature from Universidade do Vale do Rio dos Sinos in Brazil. Gillenwater is fluent in Portuguese, Spanish and English.
Siggi Meissner heads global drilling operations and the corporate engineering group for Nabors. He assumed this role during April 2015. In this capacity, he directs a global network of drilling rigs and service and support facilities.
In 1993, Meissner joined Nabors as president of international drilling operations. Prior to that time, he was General Manager of Deutag’s international operations. He began his career with Dyvi Offshore as a derrickman and worked up through the ranks before joining Deutag as a drilling engineer.
Meissner received his degree in petroleum engineering from the Technical University of Clausthal-Zellerfeld in Germany specializing in drilling, reservoir and production engineering. An avid cyclist, he leads a large Nabors contingent in the annual MS 150 Bike Ride, which raises money for multiple sclerosis research.
Christopher Papouras directs global operations for Nabors Drilling Solutions.
Papouras was also President of Epoch Well Services before its merger with Canrig in 2009. He began his career with Nabors as assistant to the chief executive officer, where he was responsible for negotiating the purchase of tubular goods and third-party rentals. He was also involved in the financial analysis of acquisition candidates and worked with ratings agencies to achieve investment grade status for Nabors’ debt.
Papouras has a B.S. in Chemical Engineering from Princeton University and Master’s degrees in both Management and Chemical Engineering from the Massachusetts Institute of Technology. He is a member of the Young Presidents’ Organization and a mentor in the Spring Branch Independent School District.
John Sanchez is chief operations officer for Canrig Drilling Technology. In this position, he leads Canrig’s global operations, with responsibility for manufacturing, sales, service and rentals.
With 30 years of international experience in the oil and gas industry, Sanchez held a number of leadership positions at Schlumberger prior to joining Nabors in February 2016. Most recently, he served as the business manager for DRILCO products within North America.
Prior to that, from 2012 to 2014, Sanchez served as the global category manager for machined parts, supporting 52 Schlumberger manufacturing centers around the world. From 2007 to 2011, he was the vice president of integrated productivity and conveyance. In this role, he managed four technology centers in North America, Europe and Asia that supported three major Schlumberger business segments. Earlier in his career, Sanchez also served as Schlumberger’s global manufacturing manager for rotary steerable systems. .
Dennis A. Smith is involved in all financial and operational aspects of the company, including interaction with the capital markets, and also directs the company’s corporate development. Prior to assuming this position, he held positions as President and Executive Vice President of the company’s international subsidiaries.
Prior to joining Nabors, Smith was an Officer and Group Vice President of Pool Energy Services Company, a public company subsequently acquired by Nabors, and was Chief Executive of the company’s independently financed Alaskan joint venture. He previously held various sales and operational management positions with the Oilwell Division of U.S. Steel, and management positions in manufacturing and production engineering with the Packard Electric Division of the General Motors Corporation.
Smith is a 1971 Mechanical Engineering Graduate from Rose-Hulman Institute of Technology, where he has been honored as a distinguished alumnus. He currently serves on the Board of Directors of Energy Alloys and is a director of the International Association of Drilling Contractors (IADC) and past member of the organization’s executive committee.
Sri Valleru is responsible for the strategic direction and development of the company’s telecommunications and information technology systems and processes, as well as office services.
Valleru began his career as a software engineer at CAPE International, a company in which he held an equity position. He was named Vice President of Technology and Development following Nabors’ acquisition of CAPE.
Valleru received his Bachelor’s Degree in Civil Engineering from Nagarjuna University in India. He has also been honored with the outstanding Asian Pacific American Employee Award from the OCA of Greater Houston.
Steve Williams heads the HSE, Quality and Risk Management functions. He also manages Nabors’ captive insurance companies and oversees security.
Williams joined Nabors as Risk Manager in 1985 and has held positions of increasing responsibility since that time. He began his career in risk management with Corporate Services in Texas and New Mexico and later joined Geosource, Inc., where he was responsible for the company’s international risk management program.
Williams is a graduate of Texas Tech University with a degree in Business Administration.
Julia Wright serves as Nabors' vice president and general counsel. In this role, she is responsible for all compliance, corporate governance and legal matters. Wright previously served as Nabors' assistant general counsel for five years. During her ten years of service with the Company, she has negotiated many mergers and acquisitions.
Prior to joining Nabors, Wright practiced with the law firms of Vinson & Elkins and Baker & McKenzie. She received her J.D. from Fordham Law School, her M.A. from Columbia University and is a graduate of Southern Methodist University with a B.A. in liberal arts.