Experimental Studies of In-Situ Microbial Enhanced Oil Recovery

Abstract

Experiments were conducted to study the feasibility of using microorganisms in EOR. particularly for the correction of permeability variation. The use of microorganisms requires the ability to transport viable cells as well as the nutrients required for cellular growth through reservoir formations. Nutrients such as glucose, peptone-protein, and phosphate and ammonium ions were transported through brine-saturated Berea sandstone cores in amounts sufficient to support microbial growth. Viable bacterial cells were transported through sandstone cores of 170-md permeability. Less than 1 % of the influent cell concentration was recovered in the effluent, indicating a high degree of cell retention inside the core. The addition of nutrients to these cores and subsequent incubation to allow for microbial growth resulted in permeability reductions of 60 to 80%. These data show that the growth of microorganisms significantly reduces the permeability of porous rock.