Effect of microbial growth on pore entrance size distribution in sandstone cores

Summary The in situ growth of microorganisms in Berea sandstone cores preferentially plugged the larger pore entrances. The largest pore entrance sizes after microbial plugging ranged from 20 to 38 m, compared with 59 to 69 m before plugging. The pore entrance size distribution of plugged cores was shifted to smaller sizes. A mathematical model based on Poiseuille's equation was found to adequately predict permeability reductions (greater than 90%) caused by microbial growth in the large pore entries.Nomenclature Q volumetric flow rate (L ₃/t) - C orifice constant (dimensionless) - A cross-sectional area (L ₂) - g gravity (L/t ²) - h pieziometric head (L) - _s transmittivity (L ²) - R _e Reynolds number (dimensionless) - a constant (dimensionless) - density (M/L ₃) - viscosity (M/Lt) - d diameter (L) - L length (L) - P pressure change (M/L ₂)