Original paper
Petroleum generation and storage in the Pennsylvanian coal-bearing strata of the Münsterland Basin, Western Germany: 3D basin modelling approach
Ghazwani, Assad; Littke, Ralf; Uffmann, Anna K.
Zeitschrift der Deutschen Gesellschaft für Geowissenschaften Band 169 Heft 4 (2019), p. 475 - 494
72 references
published: Mar 12, 2019
published online: Aug 7, 2018
manuscript accepted: May 16, 2018
manuscript revision received: May 16, 2018
manuscript revision requested: Apr 5, 2018
manuscript received: Mar 7, 2018
ArtNo. ESP171016904001, Price: 29.00 €
Abstract
Ghazwani, A., Littke, R., Uffmann, A.K., Baniasad, A. & Röth, J. (2018): Petroleum generation and storage in the Pennsylvanian coal-bearing strata of the Münsterland Basin, Western Germany: 3D basin modelling approach. – Z. Dt. Ges. Geowiss., 169: 475–494, Stuttgart. Abstract: The Münsterland Basin in Western Germany is characterised by a Cretaceous sedimentary sequence of up to about 2 kilometres thickness unconformably overlying coal-bearing Pennsylvanian and older sedimentary rocks folded and faulted during the Variscan Orogeny. The structure of the basin is complex, with depocentres moving northwards in time during the Pennsylvanian due to the prograding fold and thrust belt and more intense tectonic deformation and shortening in the south. Based on vitrinite reflectance and fission track data, the burial history, amounts of uplift and temperature histories were reconstructed in a 3D basin model by Uffmann & Littke (2013) and modified for this study. The model indicates that maximum burial, maximum temperatures and present-day maturities were reached for most of the area just before or during the initial phase of the Variscan uplift, which affected this area in the late Pennsylvanian. However, some areas experienced almost the same high temperatures again during the Late Cretaceous due to significant reburial leading to additional thermal hydrocarbon generation there. Due to long-lasting mining activities, the coals of the Pennsylvanian are known to be gas-rich to various extents. Therefore, the model was also used to calculate natural gas generation from both coals and marine black shales. Thus, we built two models simplifying the complex geology with more than hundred coal seams: one model with an assumed 30 m thick coal seam and the other one with an assumed 30 m thick black shale unit within the lower Westphalian (rather than implementing hundred thin coal seams and various black shales). The study provides timing and extent of hydrocarbon generation and estimates of accumulation and adsorption masses of natural gas within the Pennsylvanian source rocks emphasising the importance of identifying areas with late gas generation as “sweet spot” targets for exploration, because much of the 300 million year old natural gas has been lost during post-Variscan intense uplift and erosion. However, the total amount of hydrocarbons generated and expelled was enormous and therefore a considerable coalbed methane potential still remains.
Keywords
Münsterland Basin • Katharina Horizon • coal • Pennsylvanian • Westphalian • basin modelling • gas generation • unconventionals • Münsterlandbecken • Katharina-Horizont • Kohle • Pennsylvanian • Westfal • Beckenmodellierung • Erdgasentstehung • unkonventionelle Lagerstätten