Micromodel systems

A high-pressure micromodel system has been constructed to visually investigate foam formation and flow behavior. This system uses glass plates, or micromodels, with the pattern of a pore network etched into them, to serve as a transparent porous medium. These micromodels can be suspended in a confining fluid in a pressure vessel, allowing them to be operated at high pressure and temperature. Because of this pressure capability, reservoir fluids can be used in the micromodel, and any effects of phase behavior or pressure- and temperature-dependent properties on foam flow can be examined. 

The high-pressure and temperature micromodel system has been used in this study to investigate the formation, flow behavior and stability of foams. Micromodel etching patterns were made from binary images of rock thin sections and from other designs for a comparison of pore effects. These experiments show how simultaneous injection of gas and surfactant solution can give better sweep efficiency on a micro-scale in comparison to slug injection. 

Effect of Micromodel Size and Dimensionality on the Interpretation of the Results. It is not knoTm how to quantitatively adjust flooding results in two-dimensional systems to bring them in line with results in their three-dimensional counterparts, but it is possible to state how the results might differ. Loss of dimensionality can lead to lower ultimate recovery, which occurs for either of two reasons first, because two-dimensional systems of the same coordination number have lower macroscopic connectivity and second, because loss of dimensionality often lowers the... 

Frequently applied micromodels assume the presence of a liquid bulk. However, some systems are without liquid bulk as in falling film reactors where a very thin layer of liquid flows over a solid surface. 

It is meaningful to examine the relation between microscale model, mesoscale model, and micromodel. For reaction kinetics, microscale and mesoscale models adopt the same kinetics that based on element reaction system. For diffusion, mesoscale model embodies two diffusion mechanisms (one for micropores and another for mesopores and macropores), and microscale model considers one diffusion mechanism since it only has micropores. No diffusion was considered within the macropores. It is obvious that the mesoscale model possesses the same theoretical foundation as the microscale model, but its application scope has been enlarged compared to the microscale model. Therefore, it could be reliably used as a tool to derive some parameters, such as effective chemical kinetics and effective diffusion parameters, for macroscale model. In the section following, we discuss the method on how to link the microscale kinetics to the lumped macroscale kinetics via the mesoscale modeling approach. 

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