The Importance of Detailed Geological Characterization for Future Expanded Use of Gas Storage in the Sustainable Energy

Salt cavern projects are often managed as pure engineering projects with little involvement of experienced geoscientists. Consequently the post-salt overburden is often regarded as being elastic, isotropic, homogenous and continuous. In fact worldwide salt mining and hydrocarbon exploration experiences proved that post-salt sections of salt domes often are exactly the opposite, heavily faulted; thus at least inelastic and discontinuous. Whereas model simplifications may accelerate project planning, ignoring these well-known subsurface facts may have severe costly consequences like for instance shearing of well casings due to fault reactivation or sinkholes at a later stage. This paper describes one of the rarely published cases where anisotropically processed 3D pre-stack depth migrated seismic data have been utilized for detailed geological site characterization at an early stage of planning a new salt cavern gas storage facility site in Jemgum (Lower Saxony basin, Germany). In contrast to commonly built pseudo 3D salt cavern models utilizing sparse input data, the creation of a true, detailed and spatially reliable 3D subsurface structural model enabled an early assessment of potential short, mid and long-term risks and its potential environmental impacts.