The United Production Partners (UPP) leadership team is comprised of operational, financial and technical experts from the top North American oil & gas operator, EnerVest Operating, L.L.C., and the esteemed energy-focused private equity firm First Reserve.

Board of Directors

Jud Walker is President & Chief Executive Officer of EnerVest, Ltd. Prior to this role, Jud was President and CEO of EnerVest Operating, L.L.C (EVOC). He also has served as EVOC Executive Vice President and Chief Operating Officer, leader of the company’s Permian Basin asset team and was head of New Ventures. Before joining EnerVest in 2009, Jud was the lead geoscientist at Chesapeake. He is a founding member of the Next Generation Giving Circle, associated with the Greater Houston Community Foundation. Jud holds a Bachelor of Science in Geology, cum laude, from Texas Christian University and a Master of Science in Geological Sciences, summa cum laude, from The University of Texas at Austin.

Alex Zazzi is President and Chief Executive Officer of EnerVest Operating, L.L.C. Prior to this position, Alex served as Executive Vice President and Chief Operating Officer. Proceeding his role as EVP and COO, he managed the company’s North Texas and Mid-Continent assets. He began his career with Schlumberger, specializing in offshore completions. Originally from Canada, Alex attended the University of Montana and earned a Petroleum Engineering degree from Montana Tech in 2003.

Travis W. Hancock joined EnerVest in 2013. As the firm’s Chief Financial Officer, he leads all financial, accounting, capital formation, and tax activities. Since joining EnerVest, Mr. Hancock has been in increasing levels of responsibility, including managing the restructuring of several legacy EnerVest funds, during the 2015-2017 global downturn in the oil and gas sector, with a key focus on incremental recovery for limited partners.  Mr. Hancock, along with John Walker, led the firm’s largest monetization in its history in a sale to TPG’s Special Purpose Acquisition Company (SPAC) in 2018, which now trades on the NYSE as Magnolia Oil & Gas Corp (MGY).  Mr. Hancock’s other responsibilities have included special projects and new opportunities. Prior to joining EnerVest, he was a member of the investment team at Wells Fargo Energy Capital, Inc. where he helped originate and manage mezzanine debt and private equity investments in the upstream sector of the oil and gas industry. Mr. Hancock has also spent time in national politics.

Mr. Hancock received a Bachelor of Science from Texas A&M University, graduating summa cum laude. Mr. Hancock is a member of the Houston Producers’ Forum and the Independent Petroleum Association of America, where serves on the Supply & Demand Committee. Mr. Hancock and his wife, Dr. Anna Lehmann, live in Houston and have two sons.

Jim is Executive Vice President and Chief Operating Officer of EnerVest Operating, L.L.C. He has served in many roles at EnerVest over the past nine years including Senior Vice President & General Manager of EVOC’s Appalachia South Asset Team, Vice President and General Manager of EVOC’s East Appalachia Asset Team, and Vice President of EVOC Shared Services. Before joining EnerVest, Jim worked as Vice President and Regional Manager for Penn Virginia Corporation and in many roles for Royal Dutch Shell. Jim currently serves as a member of the Board of Directors for the Virginia Oil & Gas Association, as a member of the Board of Directors of TruPoint Bank, as a member of the Advisory Board for the West Virginia University Energy Land Management program, and as an Advisory Board member for the Virginia Tech University Virginia Center for Coal and Energy Research. Jim earned his B.S. degree from the University of Tennessee and his M.B.A. from Houston Baptist University.

Neil Wizel is a Managing Director at First Reserve. First Reserve is a leading global private equity investment firm exclusively focused on energy. Prior to joining First Reserve in 2007, he was a member of the Investment Staff at Greenbriar Equity Group. Prior to Greenbriar, he was a Financial Analyst in the Leveraged Finance/Financial Sponsor Group at Credit Suisse First Boston. Mr. Wizel holds a B.A. from Emory University.

Thomas S. Amburgey, Director, joined First Reserve in 2012. Mr. Amburgey’s responsibilities include investment origination and structuring, due diligence, execution and monitoring. Prior to joining First Reserve, he was an Analyst in the Financial Sponsors and Leveraged Finance division at UBS Investment Bank. Mr. Amburgey holds a B.B.A. and a Master of Accountancy from the University of Georgia.

Carolina Sierra, Vice President, Technical, joined First Reserve in 2019. Ms. Sierra’s responsibilities include due diligence and monitoring – with a technical reservoir perspective in upstream- and midstream-related investments and early theme and trend identification throughout the energy value chain. Prior to joining First Reserve, she was an Associate at Guggenheim Partners in the E&P Asset Acquisitions & Divestitures practice. Prior to Guggenheim, she worked for BP as a Reservoir Engineer and Schlumberger as a Drilling and Field Engineer. Ms. Sierra holds a B.S.E. from the University of Michigan and an MSc from Delft University of Technology.

Steve Mueller has served as a First Reserve Senior Advisor since 2016. Prior to this, he spent 8 years with Southwestern Energy in various management roles including Chairman of the Board, President and CEO, and President and COO. Prior to holding these positions, Mr. Mueller served as Executive Vice President of CDX Gas after spending 6 years with Houston Exploration Company where he held various senior positions. In addition, Mr. Mueller has 26 years of further industry experience with Belco Oil and Gas Corporation, American Exploration, Fina Oil and Tenneco Oil. Mr. Mueller is a member of the Board of Directors of the Gas Technology Institute (GTI) and holds a B.S. from the Colorado School of Mines. Mr. Mueller also currently sits on the Board of Directors for C&J Energy Services (NYSE: CJ).