Pseudo-3D Modeling of the Combined Evolution of Salt and Sediments - A North Sea Case History

Kenneth Petersen, Ian Lerche

Reconstruction of salt flow has often been restricted to restoration in two dimensions. Because salt flow does occur in three dimensions, a more complicated modeling procedure must be applied. Even with observations from 3-D seismic, the number of parameters required for a proper 3-D restoration makes quantitative modeling severely complicated.

By using an inverse method that models the combined evolution of salt and sediments self-consistently, a number of sections crossing the same salt structure can be modeled. These 2-D sections must be consistent with each other and, taken together, the sections constitute a pseudo-3D model of the salt and sediment evolution.

An application is given to an asymmetric salt diapir in the Norwegian-Danish Basin which exemplifies the quantification of the present-day salt shape and of the combined pseudo-3D evolution of salt and sediments. Each of the 2-D evolution histories illustrates the complexity of the salt and sediment dynamics and a quantitative measure is given of the 3-D salt flow pattern with time. Pseudo-3D modeling enables an improved quantification to be made of the trap quality around salt structures - both for the present day geometries and their evolution with time.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995