Modeling of compaction and overpressuring in sedimentary basins

This paper deals with the modeling of compaction and overpressure development in sedimentary basins during sedimentation. The modeling is based on an extension of a formulation for one-dimensional sedimentation and large-strain consolidation of sedimentary layers increasing in thickness with time. A modified formulation is presented using constitutive models for sediment compaction and permeability changes, which are based on experimental results for different clays compacted to effective stresses of up to 100 MPa. The main aim of the modeling is to improve the knowledge of overpressuring generated by mechanical compaction in sedimentary basins. Parametric studies were carried out to determine the effects of deposition rate and sediment properties on predicted overpressures, effective stress, porosity and permeability in sedimentary basins. Finally, a simplified North Sea sedimentary basin is analyzed in order to illustrate the use of the model, and to gain further understanding of how pore pressures have developed in some areas in the North Sea.