SALT MODELLING

SALT MODELLING

The dynamic evolution of salt structures may totally change the stratigraphic and structural picture throughout the geohistory of the basin. Timing of the evolution of salt structures may be crucial for exploration, as the structural traps as we see them on present day seismics may not have been in place when hydrocarbons migrated into the area.

Salt has low density and deforms as a viscous fluid, whereas the surrounding sediments deform by brittle and elastic mechanisms. This nature may reduce compaction of subsalt sedimentary sequences as deformation is taken up by salt reactivation. BMT (our in-house basin modelling software) has an algorithm for treating movements of salt. Salt reconstruction is accomplished by a mass-editor enabling to mimic salt growth or withdrawal. The mass editor is applied at relevant time steps during the basin evolution.

Due to the high thermal conductivity of salt, salt structures act as vertical heat-pipes and thereby lead to higher temperatures above the salt than in the adjacent rocks. This could have possible impact on hydrocarbon maturation and porosity loss due to diagenetic effects, in the area above the salt. The temperature effects of salt could be modelled in BMT.

Salt-related deformation induced by the flowing salt may affect potential petroleum reservoir in the vicinity of salt structures. The effects of salt on possible fault reactivation and fracture formation may be of importance for understanding trapping, sealing, and migration of hydrocarbons in areas dominated by salt. We model the stress effects using the commercial software Comsol Multiphysics (www.comsol.com).

Read more about common topics for studies on salt.