Investigating the depositional environments using particle-size analysis of Lower Cretaceous sandstone reservoirs, Biyadh Formation, Saudi Arabia

Abstract

This study employed particle-size analysis on twenty friable sandstone beds from two outcrops of the Biyadh Formation, which acts as a water aquifer, petroleum reservoir, and CO2 capturing reservoir. Hydrodynamic processes and depositional environments were identified using bivariate plots, Visher diagrams, Passega diagrams, and linear discriminant functions (LDF). The results reveal that the beds of Outcrop A mainly consist of medium- to well-sorted, medium-grained sandstone that is near-symmetrical and mesokurtic. However, Outcrop B comprises medium-sorted, medium-grained sandstone beds that are near-symmetrical and leptokurtic. All the beds in Outcrop A and B are unimodal. Furthermore, Visher and Passega diagrams indicate that the particles of Outcrop A were mostly transported by rolling, saltation, and suspension. In contrast, the particles of Outcrop B were transported by rolling, saltation, suspension, and graded suspension. The LDF technique shows that the depositional environments were beach, aeolian, fluvial, and shallow marine.