ALBERT

Description: Source- and age-related biomarker and isotopic data were measured for more than 1000 crude oil samples from wells and seeps collected above approximately 55°N latitude. A unique, multitiered chemometric (multivariate statistical) decision tree was created that allowed automated classification of 31 genetically distinct circum-Arctic oil families based on a training set of 622 oil samples. The method, which we call decision-tree chemometrics, uses principal components analysis and multiple tiers of K -nearest neighbor and SIMCA (soft independent modeling of class analogy) models to classify and assign confidence limits for newly acquired oil samples and source rock extracts. Geochemical data for each oil sample were also used to infer the age, lithology, organic matter input, depositional environment, and identity of its source rock. These results demonstrate the value of large petroleum databases where all samples were analyzed using the same procedures and instrumentation. Ken Peters has a Ph.D. in geochemistry from _the University of California–Los Angeles and has used numerical modeling to study petroleum systems at the U.S. Geological Survey since 2002. He spent 15 years with Chevron and 9 years with Mobil and ExxonMobil and taught petroleum geochemistry and basin modeling at Chevron, Mobil, ExxonMobil, Oil and Gas Consultants International, University of California at Berkeley, and Stanford University. Ken is principal author of The Biomarker Guide (2005, Cambridge University Press). Scott Ramos has a Ph.D. in analytical chemistry and chemometrics from the University of Washington. Scott worked at the National Oceanographic and Atmospheric Administration National Marine Fisheries Service in Seattle, the State Pollution Control Agency in Rio de Janeiro, Brazil, the Federal Amazon Research Institute in Manaus, Brazil, and, for 22 years, at Infometrix, Inc. His publications include studies of contamination by polycyclic aromatic hydrocarbons, essential oil characterization, and chemometrics. John Zumberge has a Ph.D. in organic geochemistry from the University of Arizona and is the senior vice president (since 1991) of GeoMark Research in Houston, which he cofounded in 1991. He was manager of geochemical and geological research for Cities Service-Occidental, general manager for Ruska Laboratories, and director of geochemical services for Core Laboratories. He has global experience in petroleum geochemistry, focusing on crude oil biomarkers. Zenon Valin is a geologist with the Western Earth Surface Processes Team of the U.S. Geological Survey. He specializes in geographic information systems and scientific illustrations and has coauthored many publications on petroleum systems. Chris Scotese (Ph.D., University of Chicago) is a professor of earth and environmental sciences at the University of Texas at Arlington, where he has taught global tectonics, earth history, basin evolution, and geographic information systems for the past 16 years. He is director of the PALEOMAP Project, an industry-sponsored research consortium whose goal is to assemble a digital atlas of earth history. Don Gautier has a Ph.D. in geology from the University of Colorado and worked for Mobil before joining the U.S. Geological Survey in 1977. He works on the World Energy and National Oil and Gas Assessment projects, with emphasis on growth of reserves in existing oil and gas fields. Don is the principal investigator to evaluate energy resources of the circum-Arctic and recently led an assessment of the San Joaquin Basin, California.