AN ADAPTIVE FINITE ELEMENT METHOD FOR MODELING SALT DIAPIRISM

Abstract

Various types of oil traps have been found to be associated with salt domes in subsurface geology. In this paper the diapiric rise of light salt layers through a denser overburden — the surrounding rocks — is modeled assuming that, in a geological time scale, salt and rocks layers behave like Newtonian fluids. A Lagrangian approach is adopted to track the interface between layers, within the framework of a finite element space discretization. An accurate description of large deformations due to salt movement is achieved using a grid adaptation technique based on geometrical refinement. Different geological cases have been simulated in order to describe the behavior of rocks and estimate the effect on diapiric growth of buoyancy force, differential loading, gravitational gliding and thin-skinned regional extension. Our computational model accounts also for sedimentation and compaction of the overburden.