Petroleum System and Thermal History of the Upper Rhine Graben – Implications from Organic Geochemical Analyses, Oil-Source Rock Correlations and Numerical Modelling
Total Page:16
File Type:pdf, Size:1020Kb
Petroleum system and thermal history of the Upper Rhine Graben – Implications from organic geochemical analyses, oil-source rock correlations and numerical modelling Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch -Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von M.Sc. Johannes Josef Böcker geboren in Gelsenkirchen Berichter: Univ.-Prof. Dr. rer. nat. R. Littke Univ.-Prof. Dr. rer. nat. D. Leythaeuser Tag der mündlichen Prüfung: 07.12.2015 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar. Preface Preface The present thesis was carried out at the Institute of Geology and Geochemistry of Petroleum and Coal at the RWTH Aachen University in the framework of an integrated petroleum exploration campaign in the central Upper Rhine Graben conducted by Engie (former GDF SUEZ E&P Deutschland GmbH) and Palatina GeoCon GmbH & Co. KG. The project was initiated by GDF SUEZ in spring 2012 in cooperation with Palatina GeoCon. Laboratory work took place in Aachen combined with research and 3D modelling at the offices of GDF SUEZ in Lingen (Ems). I Acknowledgements Acknowledgements At this point I like to express my sincere gratitude to all who contributed to a successful outcome of this PhD thesis. At first I like to thank all who initialised the PhD thesis at GDF SUEZ in Lingen (Ems) and the Institute of Geology and Geochemistry of Petroleum and Coal in Aachen. Many thanks to Prof. Ralf Littke for all his kind support, expertise, advisements and supervision during this project. I acknowledge the support and financial sponsoring by GDF SUEZ E&P Deutschland GmbH and Palatina GeoCon GmbH & Co. KG. In particular, I am grateful for the funding and sponsorship with respect to core samples, structural maps and access to well database. I sincerely thank all geologists and geophysicists from GDF SUEZ in Lingen for their cooperation and qualified support, especially Han van Gils, Bernd Klug, Frank Görisch, Hans-Michael Trautnitz, Astrid Forster, Tim Catlin and Robert Bussert, for all their expert contribution and support for this research work. Many thanks to Reinhard Sachsenhofer, Kirsten Grimm, Werner Fielitz and Christoph Hartkopf- Fröder as reviewers of my scientific articles. I am grateful for the critical and constructive comments on earlier versions of manuscripts. Their extensive review and suggestions considerably improved the manuscripts. Many thanks to Norbert Micklich and Mr. and Mrs. Oechserl for providing samples from clay pit Unterfeld, the Jungk Company in Wöllstein for providing samples of the Upper Rupelian Clay, and the Wienerberger Company for providing Liassic samples from Lixhausen. I like to thank the geological survey of NRW for providing samples from well Rülzheim 1, Frankenthal 10, and outcrop Siebeldingen and Robert Bussert for samples from outcrop Mühlhausen. Thanks to Prof. Jan Schwarzbauer for advice with respect to molecular geochemistry, to Donka Macherey for preparing polished sections for vitrinite reflectance measurements and Alexander Stock for kinetic measurements at GFZ in Potsdam. I also like to thank all PhD students and employees at the EMR Aachen for their work, help and expert contributions. Finally, a huge thank to my family. I am deeply grateful for all the given support, otherwise a successful realisation of my dissertation had not been possible. Thanks to my friends for backing and getting sidetracked. And my very sincere, whole-hearted thank to Johanna in gratitude for all the support and encouragement. II Structure of the dissertation Structure of the dissertation The present thesis is subdivided into three separate parts. The first investigates the source rock potential of the Rupelian Fish Shale, which is the most important source rock in the northern URG. Results of this study “Source rock characterisation and thermal maturity of the Rupelian Fish Shale (Bodenheim Fm./Hochberg Subfm.) in the central Upper Rhine Graben” were published 2014 in the German Journal of Geoscience (Zeitschrift der Deutschen Gesellschaft für Geowissenschaften (ZDGG), 165 (2), p. 247-274). The second part focuses on the Liassic Black Shales and their thermal maturity, which is of key interest in order to understand the expulsion of hydrocarbon as well as the development of the basin. Results of this study “Thermal maturity and petroleum kitchen areas of Liassic Black Shales (Lower Jurassic) in the central Upper Rhine Graben, Germany” were published 2016 (online in May 2015) in the International Journal of Earth Sciences (Geologische Rundschau, 105 (2), p. 611-636). Lastly, the third part gives an overview on source rocks and the petroleum system of the URG with focus on early Tertiary source rocks and new insights in the migration systems. This study “An overview on source rocks and the petroleum system of the central Upper Rhine Graben” was submitted as well to the International Journal of Earth Sciences and is accepted for publication (accepted 6 April 2016). Furthermore, results of the dissertation were presented at the DGMK conference in Celle in April 2014 (“Modelling the Hydrocarbon Generation Potential of Source Rocks in the Upper Rhine Graben, Germany”). III Abstract Abstract The Upper Rhine Graben (URG) forms the central section of the European Cenozoic Rift System and is a mature hydrocarbon province. During previous exploration periods, about 50 oil fields and several gas fields were discovered accompanied by a huge number of exploration and production wells and numerous seismic profiles. Surprisingly, in 2003 a geothermal well found oil in the Buntsandstein reservoir and discovered unexpectedly the Römerberg oil field, which promptly doubled the total recoverable reserves (produced oil plus remaining reserves) in the German part of the URG. This discovery opened-up a new exploration play and implicated a review and revaluation of the petroleum system of the URG. Four distinct oil families occur in the URG. Three of those are of economic interest. The oldest oils are derived from the Liassic Black Shales (oil family C). These are the major source rocks for oil fields in the Alsace and southern URG as well as for the large oil fields Pechelbronn, Landau and Römerberg. Furthermore, several Tertiary source rocks exist. At many places high wax oils occur, which originated from early Tertiary (Eocene) coaly shales and sapropelic coals (oil family B). Oils from the Rupelian Fish Shale (Hochberg-Subfm.) occur especially in the northern and central URG (oil family D). In addition, highly viscous, sulphur-rich and early mature oils generated from the Corbicula- and Hydrobienschichten exist (Oil family A). These oils occur especially in the Micoene to Quaternary subsidence center, the Heidelberg-Mannheim-Graben. The oil family A oils are economically not relevant, but are of interest in order to derive kitchen areas and directions of migration. In this regard, the dissertation is subdivided into three studies. The first one focuses on a source rock characterisation of the Rupelian Fish Shale, which is the major source rock of the large oil fields Stockstadt, Eich-Königsgarten, and further smaller oil fields in the northern URG, where the Liassic source rocks are eroded. Based on petrographic and geochemical analyses the Fish Shale was characterised as good to very good source rock containing typical type II kerogens, 4-5.5 % TOC and Hydrogen Index (HI) values of 450-550 mg HC/g TOC (at an immature state). Special biomarkers such as characteristic sterane distributions, age-related markers such as oleanane, or a highly branched isoprenoid C25 with origin from marine diatoms enable reliable oil-source rock correlations. The Fish Shale is distributed in the entire graben in uniform facies. Thus, the thickness and thermal maturity are the factors controlling the amount of generated hydrocarbons. The latter is the limiting factor for missing oils derived from the Fish Shale in the Alsace and southern URG (south of Karlsruhe). This was shown by a vitrinite reflectance map, which distinctly identifies kitchen areas of the Fish Shale. Existing reservoired oils derived from the Fish Shale were correlated to these kitchen areas and migration pathways and directions were identified. The second part analyses the Liassic source rocks with focus on their thermal maturity. An investigation beyond the borders of the URG showed that the Posidonia Shale (Lias ε) reached a IV Abstract maturity of about 0.5-0.6 % VRr within the graben area and its surroundings before the formation of the URG in the Eocene. Liassic outcrops situated at the graben margin, in the Alsace, in the Swabian Alb, in the foreland of the Alps, and samples from shallow wells (ca. < 1000-1500 m) within the graben show a quite uniform maturity, which results from a relatively coherent burial history and temperature increase before the formation of the URG. In addition, this maturity indicates that the Liassic source rocks did not expel a significant quantity of oil before the formation of the graben. A map of the thermal maturity of the Posidonia Shale reveals a mid-oil window mature source rock in major parts of the central URG, which also reached the wet gas window in the area of Karlsruhe. The final third part gives an overview on source rocks and the petroleum system of the URG. Especially the Posidonia Shale can be characterised as excellent source rock and generated most oil in the URG. High mean TOC values of 8 % and HI values of > 550 mg HC/g TOC characterise the Posidonia Shale at an immature stage. Moreover, the bituminous Lias α marls and shales have important additional source rock potential and contributed to the oils of family C. Furthermore, new insights on source rocks of the different oil families and several new oil-source rock correlations are presented and the distribution of oil families in regard to migration pathways is discussed. The high wax oils (Family B) are heterogeneously distributed, but occur especially in the northern and central URG, in the latter predominantly in the western part.