| dc.description.abstract | Enhanced oil recovery processes rely upon the use of chemical, thermal or physical energy to produce the residual oil in reservoir after primary and secondary (water flood) recovery processes. Microbial improve oil recovery (MIOR) is one of the tertiary oil recovery methods, which can change the chemical and physical properties of the reservoir fluids and rock by bio-products and bacteria itself.
The potential recovery mechanisms involved in MIOR processes include interfacial tension reduction, wettability alteration, selective plugging, gas generation, acid production and mobility ratio reduction. The effect of these mechanisms varies for different kinds of bacteria and environment conditions. But based on experimental results of core flooding and glass micromodel flooding experiments, interfacial tension reduction, wettability alteration and selective plugging are proposed as most important recovery mechanisms during the MIOR process.
The objectives of this thesis work are to study the mechanisms of MIOR by using simulation software and find the main mechanisms contributing to increased oil recovery. Two kinds of simulation software are used in the simulation study part, ECLIPSE and COMSOL Multiphysics. Interfacial tension reduction, wettability alteration and selective plugging are proposed as increased oil recovery mechanisms during the simulation work, the main mechanisms can be determined by analyzing each mechanism separately.
In the core flooding simulation the selective plugging is the main mechanism, other mechanisms do not contribute too much on increasing oil recovery. For COMSOL simulation part, the COMSOL Multiphysics software has been proved to be a good simulator for oil displacement simulation, and the threshold pressure can be determined by using COMSOL. Interfacial tension reduction and selective plugging are regarded as main mechanisms in MIOR process, further more, simulation models also are built for oil displacing water process by using COMSOL. | nb_NO |
