Tectonic control on the Early Cretaceous Bentheim Sandstone sediments in the Schoonebeek oil field, The Netherlands

The reservoir rock of the Schoonebeek oil field is formed by the sandstones of the Bentheim Sandstone Member. The sedimentology and depositional environment of this sandstone have been extensively studied, but the relationship between the geometry of the sandstone and tectonic activity in the Schoonebeek area remains poorly understood. 355 boreholes and two threedimensional (3D) seismic surveys were used to study this relationship. An eroded zone in the west of the field and an area where the original depositional thickness is still intact were identified. Using the ezValidator software package it can be seen that uplift of a local anticline played an important role in the erosion of the sandstone. Deposition of the sands of the Bentheim Sandstone Member and the overlying Vlieland Sandstone and Claystone formations occurred on an unstable changing palaeotopography, whereby the instability was probably driven by halokinetic movement of the underlying Late Permian Zechstein salt. Syndepositional tectonic movements affected local thickness variations in the Bentheim Sandstone Member in the west of the field, leading to westwards thinning.