3D-facies and reservoir modelling of the buntsandstein reservoirs of the northwestern thuringian syncline

3D-Facies and reservoir modelling of the Buntsandstein reservoirs of the northwestern Thuringian Syncline

Abstract

An integration of stratigraphic, sedimentological and structuralcharacteristics of the Lower Triassic in the northwestern Thuringian Syncline (Thüringer Becken) has been performed. A stratigraphic-sedimentological model has been created for the Middle Buntsandstein Subgroup(Volpriehausen, Detfurth, Hardegsen and Solling Formation) and the structural model has been built from the top of the Zechstein Group to the top of the Middle Buntsandstein Subgroup. By integrating allavailable surface and subsurface information (regional geology, core logs, sample descriptions, electric log and structural interpretation) in a 3D-model using the software Irap RMS 2009 and KINGDOMsuite version 8.2 allows to create a sedimentogical-stratigraphic-structural model. The Middle Buntsandstein Subgroup of the northwestern Thuringian Syncline consists of about fifteen (15) finingupward cycles that provide a high resolution lithostratigraphic framework. The cycles apparently reflect climate fluctuations between wet and dry periods driven by Milankovitch variations in solarirradiation. The cycles can be well correlated across the studied area. The successions of the Middle Buntsandstein are mainly characterized by continental clastic deposits reflecting the interaction ofeolian, fluvial and lacustrine environments. Their total thickness varies between 130 and 230 m. In the Thuringian Syncline, NNE-SSW tensional and transtensional stresses acted during the Buntsandsteindeposition creating subsidence patterns, uplifted areas as well as a regional angular unconformity. The main structural element in the study area is the Schlotheimer Graben. It comprises three mainnormal faults striking NW (305°) with stratigraphic throws from 20 to 280 m and two minor faults of similar strike with displacements of 20 m. On the Eichsfeld Swell uplift and erosion occurred after...