Storage, flow and contamination of groundwater in bioturbated strata: Example from the upper Jubaila Formation, Saudi Arabia

Abstract

This study investigates the potential of bioturbated strata within the Jubaila Formation in Saudi Arabia to serve as water aquifers with exceptional storage and flow capacities. Additionally, it explores scenarios related to remediating oil as a possible contaminant in these aquifers. The study employs multipoint statistics modeling to model the burrow attributes of the dominant burrow, Thalassinoides, aiming to understand how the burrow network impacts the flow capacity of the water aquifer in these strata. The modeling results demonstrate that Thalassinoides can generate a connected burrow network responsible for permeability that may exceeds 3.5 Darcey, indicating potential for super permeable aquifers. The study also modeled a hypothetical aquifer for the bioturbated strata in the Jubaila Formation and conducted fluid flow simulation to understand the behavior of oil as a contaminant in such highly permeable strata. The simulation results suggest challenges in extracting oil from aquifers with such permeability, as more than 50% of the oil remains in the aquifer despite the simulation being run for ten times the duration it took for a water breakthrough occurred. This study provides valuable insights into the potential for bioturbated strata in carbonate succession to form water aquifers with exceptional storage and flow capacities. The study also highlighted the challenges associated with remediating oil contamination in such environments.