Large-scale injection complexes, which border many Paleogene deep-water sandstone accumulations in the North Sea, are modeled as emplaced in a single phase by sand fluidization into preexisting fractures and as extruding on the sea floor. The energy involved in the emplacement of the large-scale dikes and extrusions is at least in the order of 10¹³ J and is mainly expended when lifting the large mass (3.1 10¹¹ kg) of granular material and fluid. Minor amounts of energy are dissipated as frictional effects. The flow velocity at the exit point on the sea floor is calculated to be initially turbulent, in the order of a few tenths of meters per second and to decrease with time. Evaluation of the dynamic properties of the process allows the assessment of the possible triggering mechanisms and supports the function of an initial liquefaction of the parent sand body. Earthquakes that could release the large amount of energy required for the liquefaction and injection of these complexes during burial are untypical of thermally subsiding basins like the Paleogene North Sea. Hence, the large pore-fluid overpressure, which is required for this process, is possibly supplied by fluid influx.