Compaction of North-Sea Chalk by Pore-Failure and Pressure Solution in a Producing Reservoir

The Ekofisk field, Norwegian North sea, is an example of a compacting chalk reservoir with considerable subsequent seafloor subsidence due to petroleum production. Previously, a number of models were created to predict the compaction using different phenomenological approaches. Here we present a different approach which includes a new creep model based on microscopic mechanisms with no fitting parameters to predict the strain rate at reservoir scale. The model is able to reproduce the magnitude of the observed subsidence making it the first microstructural model which can explain the Ekofisk compaction.