Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hanson, A. D. Articles by Moldowan, J. M. Search for Related Content GeoRef GeoRef Citation

Organic geochemistry of oil and source rock strata of the Ordos Basin, north-central China

¹ Department of Geoscience, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454010, Las Vegas, Nevada 89154-4010; andrew.hanson{at}unlv.edu
² Chevron Energy Technology Company, 6001 Bollinger Canyon Road, San Ramon, California 94583; britts{at}indiana.edu
³ Department of Geological and Environmental Sciences, Stanford University, Stanford, California 94305-2115; moldowan{at}pangea.stanford.edu

Andrew Hanson is an associate professor at the University of Nevada Las Vegas. He conducts research related to oil and source rock organic geochemistry, extensional basin analyses in the southwestern United States, and hydrocarbon-migration issues associated with salt structures. He has a Ph.D. in geological sciences from Stanford University.

Bradley Ritts received his Ph.D. in geological sciences from Stanford University in 1998. He worked as an exploration geologist for Chevron Overseas Petroleum in 1998 and 1999 and then moved to Utah State University as an assistant professor. In 2005, Ritts was appointed the Robert R. Shrock Professor of Geological Sciences at Indiana University. Beginning in September 2007, Ritts rejoined Chevron Energy Technology Company in San Ramon, California. His research expertise is in regional interpretation of sedimentary basins, continental tectonics, and clastic sedimentology.

Mike Moldowan attained a B.S. degree in chemistry from Wayne State University (1968) and a Ph.D. in chemistry from the University of Michigan (1972). After a postdoctoral fellowship at Stanford University, he joined Chevron in 1974, where he developed technology related to biomarkers. Since 1993, Moldowan has been a research professor in Stanford University's Department of Geological and Environmental Sciences.

Paleozoic and Mesozoic strata and a suite of oil samples from wells in the Ordos Basin were studied to determine which strata are source rocks for oil produced in the basin. Analyses included total organic carbon, Rock-Eval pyrolysis, vitrinite reflectance, and conventional biomarker analyses on source rock extracts.

Results reveal that Carboniferous coal and organic-rich fluvial-deltaic mudstone samples appear to be gas prone and mature to overmature. Both Upper Triassic and Middle Jurassic lacustrine mudstone samples contain organic matter of sufficient quantity and good quality to be slightly immature or to have low thermal maturity. Oil-oil correlations result in the establishment of one genetic family that can be divided into subfamilies based on degree of oxicity in the source environment, differences in thermal maturity, and differences in clay versus carbonate content of the source rock. An oil-source rock correlation is established between produced oil and Upper Triassic source rock strata. Vitrinite data indicate that the source rock is more thermally mature in the western part of the basin than in the east. These results should drive future exploration strategies for the basin.

A bitumen vein is classified as pre-oil solid bitumen using biomarker data. Age-related biomarkers suggest it is derived from a pre-Jurassic source rock. Similar veins in other basins globally are linked to very rich source rocks.