The Posidonia Shale of northern Germany: unconventional oil and gas potential from high-resolution 3D numerical basin modelling of the cross-junction between the eastern Lower Saxony Basin, Pompeckj Block and Gifhorn Trough

Abstract

A high-resolution three-dimensional (3D) numerical basin model, incorporating the eastern part of the Lower Saxony Basin (LSB), the Gifhorn Trough and parts of the southern Pompeckj Block, was built to reconstruct the thermal and structural evolution of this area. The estimation and calculation of the unconventional oil and gas resource density within the Posidonia Shale source-rock unit was the main objective of this study. Incorporating organic–geochemical data for the Posidonia Shale source-rock units, such as compositional petroleum generation kinetics data, allowed a more accurate prediction of hydrocarbon potential compared to large-scale models of the area, as well as a better prediction of bulk adsorption capacity and adsorbed gas content. For the accurate calculation of oil and gas contents within the source-rock lithologies, mineralogy and physical properties of the rocks, such as compressibility, sorption capacity and porosity, are important as well as organic matter quantity, quality and thermal maturity. These properties in turn are strongly dependent on the vastly different burial/uplift histories within the LSB, Gifhorn Trough and the Pompeckj Block. The Gifhorn Trough, large parts of the Pompeckj Block and the flanks of the LSB are interesting concerning the unconventional oil potential, with current source-rock maturities between 0.65% and 1.2% vitrinite reflectance. Central parts of the LSB and small parts of the Pompeckj Block show inherent unconventional gas potential. Methane adsorption capacity is influenced by the burial/uplift history of the basin, which stresses the importance of structural and geochemical interlocking in understanding unconventional hydrocarbon systems.

Assessment of continuous oil and gas resources in Jurassic Posidonia Shales of Greece and Albania, 2019

“…Jurassic Posidonia organic-rich shales form some of the most prolific petroleum source rocks in Europe and have been studied extensively (van Bergen and others, 2013; Song and others, 2017; Stock and Littke, 2018). Jurassic Posidonia Shales in Greece and Albania contain Type II and Type I organic matter, have as much as 20 weight percent total organic carbon, have hydrogen indices as much as 565 milligrams of hydrocarbon per gram of total organic carbon, are up to 80 meters thick, and are interpreted to be thermally mature both for oil and gas (Rigakis and Karakitsios, 1998;Zelilidis and others, 2003;Karakitsios and Rigakis, 2007;Barbullushi, 2013;Karakitsios, 2013;Spathopoulos and Sephton, 2013;Zelilidis and others, 2013).…”

Mesozoic resource potential in the Southern Permian Basin area: the geological key to exploiting remaining hydrocarbons whilst unlocking geothermal potential

“…However, geoscience is central to the identification of resources and can contribute to the continuing debate over its extraction. Stock & Littke (2018) give an example of how the Posidonia shale may be associated with unconventional resources in the Lower Saxony Basin.…”

“…Posidonia and Kimmeridge shales: e.g. Oschmann 1991;McArthur et al 2008;Pierce et al 2008;Sachse & Littke 2018;Stock & Littke 2018). The Jurassic sequence is, however, only preserved in areas of the basin that were protected from a late Jurassic-Early Cretaceous inversion episode (related to the Alpine collisional phase: e.g.…”

Assessment of continuous oil and gas resources in the Lower Saxony Basin of Germany, 2020

“…The organic-rich Early Jurassic Posidonia Shale was deposited across central Europe and is present throughout the Lower Saxony Basin, and the organic-rich Early Cretaceous Wealden Shale was deposited in the western half of the basin (Kockel and others, 1994;Stock and Littke, 2018). In the southern part of the basin, these source rocks were buried by several kilometers of Jurassic and Cretaceous sediments and were heated well into the thermal gas window, evidenced by vitrinite reflectance values of as much as 5 percent or more (Petmecky and others, 1999).…”