Source Rock Potential of Selected Mesozoic and Cenozoic Sediments of the North Alpine Foreland Basin in Germany

Jonathan Efe Oriabure

Research output: ThesisMaster's Thesis

Abstract

Petroleum source rocks are fine grained sediments containing sufficient amounts of organic matter capable of generating and releasing enough hydrocarbons (oil and gas) into accumulations. Besides the amount of organic matter, kerogen type, maturity and thickness are important parameters for the petroleum generative potential. In addition, information about the depositional environments helps to understand differences in the potential of source rocks. Organic geochemical studies support the interpretation of the environments as well as the correlation between source rocks and oils. The German sector of the North Alpine Foreland Basin hosts oil and gas reservoirs in Mesozoic and Cenozoic strata. In contrast to Austria where contributions to the thermogenic petroleum system are exclusively from Lower Oligocene units (Schöneck, Dynow, Eggerding formations) additional Mesozoic source rocks are available in the German sector of the basin. To provide principal learnings on the contributions of Mesozoic and Cenozoic potential source rocks to the petroleum systems of the German part of the basin, 90 core samples were obtained from 15 different wells. The age of the sample set range from the Triassic to the Paleogene. To evaluate the hydrocarbon generative potential of the source rocks and their depositional environments, bulk geochemical parameters (TOC, TC, and Rock Eval pyrolysis), organic petrographic as well as biomarker analysis were carried out. The Upper Jurassic Posidonia Shale shows very high TOC contents (up to 10 wt.%) and HI values up to 605 mgHC/gTOC and is the most favorable Mesozoic source rocks. Samples from the Lower Oligocene Schöneck Formation also have high TOC contents up to 8.4 wt.% and HI values ranging between 80 and 630 mgHC/gTOC confirming the very good source rock potential. Other Mesozoic (Upper Triassic, Lower and Middle Jurassic, Upper Cretaceous) samples exhibit generally a poor to fair hydrocarbon potential. Oligocene samples show a wide range from a poor hydrocarbon potential to a good one. All analyzed sections were deposited in marine environments under dysoxic to oxic conditions. Organic petrographic analyses of Cenozoic samples show higher contributions of landplants (vitrinite) in the organic matter whereas Mesozoic samples tends to have more marine organic matter (alginite). Biomarker analyses confirm higher landplant contributions in Lower Oligocene samples in comparison to Lower Jurassic sediments where organic matter is mainly derived from marine organisms. The maturity of the samples ranges between immature and early mature.
Translated title of the contributionMuttergesteinspotential Ausgewählter, Mesozoischer und Känozoischer Sedimente des Alpinen Vorlandbeckens in Deutschland
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Groß, Doris, Supervisor (internal)
Publication statusPublished - 2020

Bibliographical note

embargoed until 26-05-2025

Keywords

  • Bavaria
  • Hydrocarbon
  • Maturity
  • Vitrinite
  • Biomarker Analysis
  • Petroleum System
  • Kerogen

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