Numerical modeling of stress perturbations caused by geometric changes of salt bodies

Abstract

Abstract We simulated the stress changes around a salt basin using a static salt structure model under compressive stress background to investigate the stress perturbation caused by different salt body shapes and amplitudes. We designed a two-layer salt model with three bulges and sags using finite element methods to calculate the stress perturbation around the salt. The results show that salt shape is closely related to the stress perturbation in the sediments around the salt, and the fluctuations of the bulge and sag (smooth or steep) can also affect the stress perturbation magnitude. Extrusion horizontal stress, normal stress, and out-of-plane stress on the plane would occur near the salt uplift in a compressive tectonic stress environment. In contrast, tensile horizontal stress, out-of-plane stress, and vertical stress would occur near the salt sag. In addition, smoother bulges are associated with smaller produced stress perturbations, and steeper sags are associated with a greater reduction of stress perturbation in the sediment. The stress of a salt structure in western Kelasu of the Kuqa depression was simulated and the applicability of previous conclusions regarding this structure was verified. These conclusions provide scientific basis for the prediction of stress perturbations around salt basin systems.