On the Origin of Sand Injectites in Bahrah Area, Northern Kuwait Bay: A Fluid Dynamic Numerical Modeling

Abstract

This work aims at describing from a fluid dynamic point of view the occurrence and the origin of sand injectites outcrops observed in two sites within the Bahrah coastal plain area, northern Kuwait Bay, through analogies with the knowledge on spouted beds. For non-cohesive systems, the channel formation can be easily reproduced through Eulerian–Eulerian computational fluid dynamics (CFD) simulations. When a certain fluid inlet velocity is set, the fluid breaks through the bed of particles creating the central channel. Cohesiveness, most likely present and relevant in the field of interest, was introduced by simulating the fluid–sand multiphase system with the CFD software adapted to satisfactorily describe previously reported field observation. To simulate such systems, the volume-of-fluid (VOF) method yielded the best results. In fact, cohesiveness can be taken into account through the Bingham model, which introduces additional parameters to estimate, and these parameters determine whether the fluid can create a central vertical channel or diagonal cracks. The CFD simulations proved to be a valid tool to reproduce laboratory-scale observations and may further explain the mechanisms behind these enigmatic formations, confirming the role of fluid–solid drag in the creation of the injectites. Future works will address further development of this approach and the application on larger scales.