Planning and Building of Salt Caverns - A Matter of Sustainability

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 anisotropic 3D pre-stack depth migrated seismic data have been utilized for geological site characterization at an early stage of planning a new salt cavern gas storage facility site in Jemgum (Lower Saxony basin, Germany). Existence of a detailed, spatially precise real 3D subsurface structural model as well enabled an early assessment of potential short, mid and long-term environmental impacts.