Velocity-Pull down

The maps “Amplitude anomalies” represent the distribution of gas indicators in the form of amplitude anomalies in seismic data, such as bright spots, gas chimneys, seismic transparent zones and velocity pull-downs. The study area covers the German North Sea sector and the depths of the first 1.000 m below the seabed. Various seismic data were available as data bases: approx. 30.000 km 2D data and approx. 4.000 km² 3D data. The mapping of amplitude anomalies indicating gas serves as a basis for further investigations into near-surface natural gas deposits in the German North Sea sector. The near-surface gas deposits up to 1.000 m depth in neighbouring countries suggest that there could also be near-surface natural gas reserves in the German North Sea sector. Three of the Dutch near-surface natural gas deposits, near the German-Dutch border, are already in production (Muntendam-Bos et al., 2009). This shows that such natural gas reserves are a potential source of energy. If smaller natural gas deposits were to be found near planned wind farms, natural gas could be extracted and burned directly on site, and during windtimes it could propel turbines. This combination could enable a continuous energy supply. Since natural gas in the sediment can negatively affect the building ground properties, knowledge about the distribution of natural gas deposits in the depths of the foundation depth of wind turbines is also important from this point of view. The location of all mapped velocity pull-downs is marked light blue. In connection with other amplitude anomalies that are considered gas indicators (bright spots etc.), velocity pull-downs have also been mapped as an indication of gas. The low seismic velocities and thus longer runtimes in gas-carrying sediments, to water-bearing sediments, lead to an apparent depression in seismic data. Literature: Muntendam-Bos, A. G., Wassing, B. B. T., Heege, J. H. t., Bergen, F.v., Schavemaker, Y.A., Gessel, S. F. v., Jong, M. L. d., Nelskamp, S., Thienen-Visser, K. v., Guasti, E., Belt, F. J. G. v. d., and Marges, V.C., 2009. Inventory non-conventional gas. TNO, Utrecht.