The decomposition of 3-D overpressure evolution model in basin scale and its application to the fault seal analysis

A new 3 - D fluid dynamics model of multilayered media has been developed, with complex burial history and capable for calibration. This new method extends the 1.5 - D approach to the solution of forward and inverse problems for excess formation pressure evolution at the basin scale, earlier proposed by the authors. The concept of a laterally conductive reservoir carrier among massive permeable rocks has been introduced. The system of sealing faults has been considered as pressure barriers in the relevant latera l drainage system. The vertical and lateral directions of pore fluid migration have been accounted recursively in two relevant mass conservation models. It allows building of an effective numerical scheme capable of modelling formation pressure compartmentalization and calibrating the sealing properties of surrounding faults. We introduce as a goal of calibration the set of independent fault attributes sensitive to the seal properties and sufficient to describe the lateral barrier. A software program packag e based on this approach has been developed, and some results of its practical application for fault analysis in the North Sea basin have been discussed.