An Analytical Model for Particle Travel through Porous Media
Lee, Kong Jin
Engineering Design Project 2008
University of Adelaide
The modelling of particle capture and deposition is used in the petroleum industry to predict fines migration and permeability decline among other facets of petroleum engineering.
Particle capture in porous media can occur via the following methods, size exclusion, electrical attractive forces (van de Waals) bridging and segregation. In the case of our model, size exclusion is considered.
The basic model for particle capture and deposition is used to produce a model that is used to analyse the micro-scale behaviour of the pore ensemble for mono-dispersed suspension flow in porous media.
The model on the macro scale is calculated from the micro-scale parameters. Based on the macro-scale model, the large scale phenomenological model functions derived; these being fractional flow and accessible porosity functions.
The functions of fractional flow and accessible porosity where incorporated into the classical deep bed filtration model .
Formula Input (unable to format for webpage)
To test the functions for the large scale model- accessible porosity (φa) and fraction flow (f) variations in the mean pore sizes, pore size variation where undertaken. It was found that with a variation of particle sizes both accessible porosity and fractional flow where affected the most.
Other findings from the model include the larger the mean pore sizing, both the fractional flow and the accessible porosity become larger.
The model also showed with increasing particle size through a fixed pore size, the rates of deposition where higher for the smaller particles compared to the larger particles. This behaviour is proof that there is size exclusion straining occurring in this model.