John Lassek is the Deputy Assistant Secretary for Subsurface Energy at the U.S. Department of Energy’s Hydrocarbons and Geothermal Energy Office. In this role, he oversees the Offices of Coal, Oil and Natural Gas, and Geothermal. He brings more than 30 years of extensive experience in the energy sector, most recently serving as Global Senior Completions Advisor at Hess Corporation, where he led completion technology strategy and large-scale field implementation across the company’s portfolio.
Mr. Lassek began his career as a field engineer at Schlumberger, the world’s largest oilfield services company. He developed his technical foundation from the ground up in operations, both domestically and internationally. He later led research and development initiatives at Schlumberger, overseeing the development and commercialization of several high-impact technologies still in use today. Throughout his career, he has been a technical leader across exploration and production companies and service companies.
Mr. Lassek serves on several industry committees and holds 13 oilfield-related patents. He earned a degree in Petroleum Engineering from the University of Alaska Fairbanks.