Experimental and Analytical Study of Microscopic Displacement Mechanisms of MIOR in Porous Media

Abstract

Abstract Pore network models are powerful tools for modeling processes and phenomena occurring in porous media. These models take the advantage of capturing a realistic representation of phenomena leading to a better understanding of pore scale processes. For processes like Microbial Improved Oil Recovery (MIOR) that incorporate numerous interconnected physical and biochemical factors, a prior knowledge of the underlying mechanisms is required. A pore network model, though small, can be implemented as a platform to understand the interactions between these acting mechanisms. In the present study, a pore network is constructed based on images of small regions of a glass micromodel. The model attempts to account for microbial growth and bio-surfactant production and their effect on flow characterization within the network. The authors have previously carried out a number of visualization experiments in a transparent pore network model to study the pore scale behavior of an alkane oxidizing bacterium, Rhodococcous sp 094, suspended in brine. Dodecane and an oxidizing bacterium were examined for evaluating the performance of microbial flooding in glass micromodels. Observations showed the effects of bacteria on remaining oil saturation, allowing us to propose the active mechanisms and also to address the problem of network morphology alteration due to microbial growth. The present work studies displacement mechanisms of an oil phase displaced by a water phase containing bacteria from the pore network modeling viewpoint. It is focused on the characterization of post MIOR morphology change for two phase flow. Consequently a methodology for incorporating major aspects of MIOR, including interfacial tension reduction, wettability alteration and profile modification into a pore network framework is introduced and developed with experimentally obtained mechanisms.