Parameter modeling for a mechanistic understanding of microbial plugging

Microbial Enhanced Oil Recovery (MEOR) by increasing sweep efficiency has been proposed as a cheap effective method of increasing oil recovery. To ensure process effectiveness in the field, a reservoir engineering design is imperative, relating microbial behavior at the pore scale to the field scale. The understanding of the quantitative relationship between nutrient consumption, microbial growth and permeability reduction is essential for field scale applications. This will ensure that predictive field scale microbial models can be created. To understand the microbial kinetics, various batch experiments were run with a Pseudomonas aeruginosa culture and sodium acetate as the nutrient. These tests were used to calculate the various parameters in the Monod kinetic expression. These parameters were used successfully to model other batch experiments. Chemostat experiments were run and modeled using these parameters as a first step towards flow-through experiments. Flow-through experiments in various porous media were then simulated using Parssim and the parameters from the batch experiments. The Monod expression proved too simplistic to adequately model the flow-through experiments as it does not account for microbes which are attached to the solid surface and hence not in direct contact with the nutrient. History matched tracer simulations showed flow patterns in various porous media configurations. These simulations also showed significant permeability reductions in the larger permeability layer of a dual layered bead pack, but minimal reductions in the lower permeability layer.