Executive Officers

Mark G. Papa, 68
Chief Executive Officer and Director

Mr. Papa is a Houston-based Partner at Riverstone. Prior to joining Riverstone in February 2015, Mr. Papa was Chairman and CEO of EOG Resources, Inc. (NYSE: EOG), an independent U.S. oil and gas company, from August 1999 to December 2013. Mr. Papa served as a member of EOG Resources’ board of directors from August 1999 until December 2014. Mr. Papa worked at EOG Resources for 32 years in various management positions. Mr. Papa was retired from December 2013 through February 2015. Prior to joining EOG Resources, Mr. Papa worked at Conoco Inc. for 13 years in various engineering and management positions. Mr. Papa has also served on the board of Oil States Industries (NYSE: OIS), a multinational oil and gas company, since February 2001 and Casa de Esperanza, a non-profit organization serving immigrants, since November 2006. In February 2016, Mr. Papa was named the Chairman of the board of OIS. In February 2010 and 2013, the Harvard Business Review cited Mr. Papa as one of the 100 Best Performing CEOs in the World; both times Mr. Papa was the highest ranked Global Energy CEO. Additionally, Institutional Investor magazine repeatedly ranked him as the Top Independent E&P CEO. He received his B.S. in petroleum engineering from the University of Pittsburgh and an MBA from the University of Houston.

Thomas J. Walker, 45
Chief Financial Officer

Mr. Walker is a New York-based Managing Director at Riverstone. Mr. Walker joined Riverstone in January 2007 as the Chief Financial Officer, a position that he still holds currently. Prior to joining Riverstone, Mr. Walker was a Principal at The Carlyle Group from June 2005, serving as the Chief Financial Officer of the jointly sponsored Carlyle/Riverstone Funds. Prior to Carlyle, Mr. Walker held similar positions at Hampshire Equity Partners, a middle market buyout fund, from February 2001 to June 2005, and Ripplewood Holdings, a private equity firm managing capital commitments in the United States and Japan, from November 1999 to February 2001. Prior to joining Ripplewood, Mr. Walker was the Director of Financial Reporting and Planning at Asbury Automotive Group (NYSE: ABG), a Ripplewood portfolio company, from August 1998 to November 1999. Mr. Walker started his career in the Metro New York office of Arthur Andersen, an international accounting firm. Mr. Walker received a B.S. in Accounting from Binghamton University in 1994.

Board of Directors

Stephen S. Coats, 43
Secretary

Mr. Coats is a New York-based Partner at Riverstone. Mr. Coats joined Riverstone in April 2008 and currently serves as the General Counsel. Prior to joining Riverstone, Mr. Coats was a partner at Vinson & Elkins LLP, a law firm specializing in the energy industry. While at Vinson & Elkins, Mr. Coats focused on domestic and crossborder M&A work within the energy industry and was outside counsel to Riverstone on many of Riverstone’s early transactions. He received his B.A. in government from the University of Texas at Austin and his J.D. from the University of Texas School of Law. Mr. Coats is licensed to practice law in the State of New York and the State of Texas.

William D. Gutermuthd, 64
Director Nominee

Mr. Gutermuth is the Founder and Chairman of Bluegrass Capital LLC, a privately owned investment and consulting firm. Since January 1, 2015, he has devoted substantially all of his professional time and energies to Bluegrass Capital. Prior to that, Mr. Gutermuth was an equity partner at Bracewell & Giuliani LLP and its predecessor firm, Bracewell & Patterson, LLP, where he practiced corporate and transactional law for almost 35 years. Mr. Gutermuth’s legal career focused principally on mergers and acquisitions, particularly in the energy industry, as well as most aspects of corporate finance and corporate governance. Mr. Gutermuth chaired Bracewell & Giuliani’s worldwide Corporate and Securities Practice from 1999 to 2005 and served as a member of the Business Group Executive Committee from 2005 to 2007, as well as serving in other leadership positions within the law firm throughout his career. Mr. Gutermuth served as a director of Main Street Capital Corporation (NYSE: MAIN), a publicly traded business development company, from 2007 to 2012 and on the Compensation and Nominating and Governance Committees during his tenure as a director. Mr. Gutermuth holds a B.S. in Political Science from Vanderbilt University and a J.D. from Vanderbilt University School of Law. Mr. Gutermuth was selected to serve on the board of directors due to his significant leadership experience and his extensive merger and acquisition experience.

Jeffrey H. Tepper, 50
Director Nominee

Mr. Tepper has been a private investor since 2013. From 1990 to 2013, Mr. Tepper served in a variety of senior management and operating roles at the investment bank Gleacher & Company, Inc. and its predecessors and affiliates (“Gleacher”). Mr. Tepper is experienced in mergers and acquisitions, corporate finance, leveraged finance and asset management. Mr. Tepper was Head of Investment Banking and a member of the Management Committee while at Gleacher. Mr. Tepper led numerous investment banking transactions on behalf of clients in a variety of industries but with a specialty in financial services and asset management. Mr. Tepper also served as Gleacher’s Chief Operating Officer, overseeing operations, compliance, technology and financial reporting. In 2001, Mr. Tepper co-founded Gleacher’s asset management activities and served as President. Mr. Tepper served on the Investment Committees of Gleacher Mezzanine and Gleacher Fund Advisors. Between 1997 and 1999, Mr. Tepper served as Managing Director of and Chief Operating Officer of Gleacher NatWest Inc. (a predecessor to Gleacher Partners). Mr. Tepper was part of the senior management team of Gleacher NatWest with oversight responsibility for middle-market senior and subordinated debt, high-yield and equity principal activities. Between 1987 and 1990, Mr. Tepper was employed by Morgan Stanley & Co. as a financial analyst in the mergers and acquisitions and merchant banking departments. Mr. Tepper received an MBA from Columbia Business School and a B.S. in Economics from The Wharton School of the University of Pennsylvania with concentrations in finance and accounting. Mr. Tepper was selected to serve on the board of directors due to his significant investment and financial experience.

Diana J. Walters, 52
Director Nominee

Ms. Walters has 28 years of experience in the Natural Resources sector, as an investment manager and equity investor, as an investment banker and in operating roles. Ms. Walters has been the owner and sole manager of 575 Grant, LLC, a company that provides advisory services in the field of natural resources, since 2014. She served as the President and Chief Executive Officer of Liberty Metals & Mining Holdings, LLC and a member of senior management of Liberty Mutual Asset Management from January 2010 to September 2014. She was a Managing Partner of Eland Capital, LLC, a natural resources advisory firm founded by her, from 2007 to 2010. Ms. Walters has extensive investment experience with both debt and equity through various previous leadership roles at Credit Suisse, HSBC and other firms. She also served previously as Chief Financial Officer of Tatham Offshore Inc., an independent oil and gas company with assets in the Gulf of Mexico. Ms. Walters currently serves on the board of directors of Platinum Group Metals (NYSE: PLG) and Electrum Special Acquisition Corporation (NASDAQ: ELECU). Ms. Walters graduated with Honors from the University of Texas at Austin with a B.A. in Plan II Liberal Arts and an M.A. in Energy and Mineral Resources.