William Lee Esch is a senior geoscience advisor at the ExxonMobil Upstream Integrated Solutions company, Subsurface Geology. He has previously worked in the ExxonMobil Exploration Company, ExxonMobil Upstream Research Company, and started his career at the Exxon Production Research Company. His expertise and interests are in, reservoir quality, low-temperature geochemistry, and predictive diagenesis. He received a Ph.D. in Geology from Louisiana State University in 1995 and a B. A. in Distributed Studies from the University of Colorado in 1989.