A priori prediction of macroscopic properties of sedimentary rocks containing two immiscible fluids
Year: 2005
Type: dissertation
Abstract: The processes in porous media governed by capillary forces, such as drainage and \nimbibition cycles, infiltration from surface water, flow, transport, adsorption and \ndissolution of contaminants, are of great importance in soil science, subsurface \ngeochemistry, petroleum engineering, and hydrology. \nThe methodology proposed in this work is devoted to the pore-scale modeling of \nsuch processes. The goal is to be able to make a priori predictions of the macroscopic \nproperties of model sedimentary rocks, such as capillary pressure curves, interfacial area, \nrelative permeabilities and electrical properties. The idea is to conduct a theoretical \ninvestigation in a simple but physically representative model porous medium. The model \nis a random packing of equal spheres for which the coordinates of the centers have been \nmeasured. Knowledge of the coordinates determines the grain space and the void space \nin the packing, thereby overcoming a long-standing difficulty for theoretical approaches \nto pore-level modeling. Geological processes, such as isopachous and pore-filling \ncementation, are simulated in the sphere pack, thus creating simple models of \nsedimentary rocks with predetermined pore space geometry. \nDespite the simplicity of the model porous medium, it is a powerful tool for \ninvestigation of the flow and transport in soils and sedimentary rocks. In particular it \nallows a priori predictions of macroscopic behavior. This capability is the most \nimportant aspect of the approach. Because there are no arbitrarily prescribed parameters, \nthe predictions can be compared directly to experiments, providing a much stronger test \nthan is possible with many other modeling approaches. \nFor example, knowledge of the pore space geometry and wettability conditions \nallows computing the exact configuration of liquid phases in porous media. This \ncapability enables the simulation of imbibition of a wetting phase into the model porous \nmedium using a physically consistent dynamic criterion for the imbibition of individual \npores. This approach allows a priori, quantitative prediction of the configuration of fluid \nphases during imbibition. This in turn allows a quantitative understanding of how \ndifferent macroscopic processes and parameters (e.g. relative permeabilities or resistivity \nindex) depend on the geologic (e.g. type and amount of cement) and physical (e.g. \nwettability) features of porous media.
Author: Mikhail Gladkikh
Language: English
Subfield: Fuel Technology
Field: Energy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1894432752