Use of Starved Cells of a Klebsiella Pneumoniae Strain Isolated from a Brazilian Oil Reservoir in a Transport and Plugging Experiment in a Sandstone Core

Abstract

: Microbial biomass can be used as a plugging agent in high-permeability zones in applications of microbial enhanced oil recover (MEOR) technology to oil-bearing strata. Laboratory tests have shown that bacterial cells, reduced in size by starvation, can penetrate more deeply when injected into a porous medium and also grow therein after nutrient is added. Transport and growth of Klebsiella pneumoniae starved cells through a Rio Bonito sandstone core (440 mD of permeability) were tested, to verify application to oil recovery. The injection of starved cells followed by nutrient medium at a flow rate of 1.8 mL/h, promoted cell growth in the core, which raised the inner pressure from 0.016 to 13.7 psi, resulting in a 99.9% reduction in the permeability of the core. The biobarrier formed persisted during the injection of 4 pore volumes of brine into the core at a flow rate of 1.8 mL/h, keeping the permeability reduced to 99.7%.