Analysis of Cenozoic Qaidam Basin: Implications for the Development of New Petroleum Plays, NE Tibet Plateau, China

Matthew Hertz, Indiana University, Dept. of Geological Sciences, Bloomington, IN, [email protected]

The study of Qaidam Basin is significant because it offers an example of a petroliferous basin that is completely non-marine, tectonically enclosed and has undergone significant climate changes over its long life of the last 50 Ma. This unique basin therefore provides the opportunity to study how variable fluvial and lacustrine systems as a result of changing climate and tectonics influence petroleum systems elements, like source, reservoir and migration pathways.

The Qaidam Basin lies in the northeastern portion of the Tibetan Plateau between the Kunlun and Qilian Mountains. It contains more than 22 oil and gas fields and at least 15 km of Tertiary sedimentary rocks. Lacustrine facies serve as source rocks and reflect changing paleoenvironmental conditions as a result of climatic and tectonic changes.

We have produced preliminary geologic maps of two study areas and measured stratigraphic sections, as a context for facies analysis and sampling. Material collected from these sections will be analyzed for biostratigraphy (palynology) to constrain age, stable C/O isotopes for chemostratigraphic correlation and paleoclimatic data, and geochemistry for source rock and environmental characterization (TOC, Rock_Eval, and biomarkers). Finally, we will conduct vitrinite reflectance analysis and utilize our compiled data to create geological and subsidence models of this unique long-lived basin.

A better understanding of the relationship between basin architecture and source rock facies in this area can lead to the development of new petroleum plays in this already producing, and similar basins worldwide.