High-resolution quantitative reconstruction of Late Cretaceous-Tertiary erosion in the West Netherlands Basin using multi-formation compaction trends and seismic data: implications for geothermal exploration

Abstract

A workflow is presented to determine the detailed, high-resolution pattern of erosion in maturely explored Sedimentary Basins by analysing the sonic log-based interval velocity patterns of nine stratigraphic intervals complemented by a geometrical approach involving the extrapolation of 3-D seismic reflectors. The jointly evaluated results of the two approaches not only provide important constraints on the inversion tectonics of a basin, but are also used to better constrain its maturity history and reservoir quality for geothermal energy. The developed workflow is demonstrated for the West Netherlands Basin. The pattern of erosion, which is consistent with observed subcrop maps, shows increasing amount of erosion towards the East and reflects the complex deformation of the basin, in which the reactivation of faults played a major role. Indirectly the results also indicate that continuous, syn-inversion sedimentation was taking place on the flanks of the basin during the Late Cretaceous, while its centre was characterised by non-deposition or slight erosion. For geothermal exploration the inferred variations of amount of erosion has implications for the spatial distribution of porosity which is an important parameter for the assessment of reservoir quality.