Abstract: Source Rock/Oil Characterization and Hydrocarbon Migration in the Tertiary Lacustrine Petroleum System of the Uinta Basin, Utah, USA

Various aspects of the geology and stratigraphy of the Uinta Basin have received considerable attention but little detailed and comprehensive information about source rock and oil geochemistry exists. Pyrolysis hydrocarbon generation experiments on a limited number of source rock samples demonstrated the variability of the sedimentary organic matter composition and hydrocarbons generated upon maturation. These results provide the basis for the investigation of a number of core samples obtained from wells drilled, throughout the basin and an extensive set of oil samples from the major producing fields. Newly developed analytical and preparative methods show potential for the characterization of the source rocks and the waxy oils generated from them.

Source rock characteristics are closely related to changes in paleolimnology and paleoclimate. Lake evolution and changes in the depositional environment can be followed with source rock analysis in combination with stratigraphic data. Temporal and spatial variations in source rock organic matter composition result in different petroleum: types, as is evident from the analysis of oil samples.

Correlation of source rock extracts and oils allow the assessment of genetical relations as well as migration pathways and distances. Logged core intervals and geochemical analyses are investigated to identify potential variations in organic matter content in the lacustrine sedimentary rocks. Mapping of source facies with core, well log and seismic data and integration of kinetic parameters, obtained from pyrolysis experiments permit modeling and quantification of hydrocarbon generation.
 

AAPG Search and Discovery Article #90940©1997 AAPG Foundation Grants-in-Aid