Modeling and Laboratory Investigation of Microbial Transport Phenomena in Porous Media

Abstract

Simulation and experimental results on the transport of microbes and nutrients in one-dimensional coreflooding experiments are presented, and the development of a three-dimensional, three-phase, multiple-component numerical model to describe the microbial transport phenomena in porous media is described. The governing equations in the mathematical model include net flux of microbes by convection and dispersion, decay and growth rates of microbes, Chemotaxis and nutrient consumption, and deposition of microbes on rock grain surfaces. Porosity and permeability reductions due to cell clogging have been considered and the production of gas by microbial metabolism has been incorporated. Governing equations for microbial and nutrient transport are coupled with continuity and flow equations under conditions appropriate for a black oil reservoir. The computer simulator has been used to determine the effects of various transport parameters on microbial transport phenomena. The model can accurately describe the observed transport of microbes, nutrients, and metabolites in coreflooding experiments. Input parameters are determined by matching laboratory experimental results. The model can be used to predict the propagation of microbes and nutrients in a model reservoir and to optimize injection strategies. Optimization of injection strategy results in increased oil recovery due to improvements in sweep efficiency.

Microbial enhanced oil recovery—a modeling study of the potential of spore-forming bacteria

“…Bacteria and substrate are continuously injected into the reservoir with the same rate. In the literature related to both enhanced oil recovery and wastewater treatment, many different injection concentrations are used ranging from 10 −5 to 10 kg of substrate per cubic meter [10,14,56,59,61]. We have chosen a substrate mass fraction from the higher concentration range.…”

“…MEOR models have been developed with different selections of mechanisms of bacterial actions [10,14,37,40,51]. However, as mentioned earlier, the main contribution to the additional oil recovery originates from in situ surfactant production and the selective plugging effect.…”

1D Simulations for Microbial Enhanced Oil Recovery with Metabolite Partitioning

“…Growth rate expressions for microorganisms are often the Monod expression based on the Michaelis-Menten enzyme kinetics and Langmuir expressions for heterogeneous catalysis (Chang et al 1991;Islam 1990;Nielsen et al 2003;Zhang et al 1992). The Monod expression is widely used, but it is still empirical regarding microbial growth.…”

“…Porosity and permeability were changed due to deposition of microorganisms. Chang et al (1991) demonstrated that the oil recovery increased by microbial plugging. Behesht et al (2008) have developed a MEOR model, where several mechanisms are taken into account; surfactant production and adsorption, salinity effects, adsorption of microorganisms, reduction of interfacial tension, and wettability changes.…”

“…Still, it was concluded that surfactant mechanism seemed the most promising to improve the oil recovery. Chang et al (1991) developed a mathematical model describing adsorption, growth and decay of microorganisms, consumption of nutrients, and other physical processes. Porosity and permeability were changed due to deposition of microorganisms.…”