A network flow model for the genesis and migration

Authors: Koukung Alex Chang W Brent Lindquist

Publish Date: 2012/09/14

Volume: 17, Issue: 1, Pages: 67-81

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Abstract

We present a network flow model to compute transport through a pore network of a compositional fluid consisting of water with a dissolved hydrocarbon gas The model captures singlephase flow below local bubble point conditions as well as the genesis and migration of the gas phase when bubble point conditions are achieved locally Constant temperature computational tests were run on simulated 2D and 3D micronetworks near bubble point pressure conditions In the 2D simulations which employed a homogeneous network negligible capillary pressure and linear relative permeability relations the observed concentration of CO2 dissolved in the liquid phase throughout the medium was linearly related to the liquid pressure In the case of no gravity the saturation of the gas phase throughout the medium was also linearly related to the liquid pressure under gravity the relationship became nonlinear in regions where buoyancy forces were significant The 3D heterogeneous network model had nonnegligible capillary pressure and nonlinear relative permeability functions While 100  of the CO2 entered the 3D network dissolved in the liquid phase 25  of the void space was occupied by gas phase and 47  of the CO2 exiting the outlet face did so via the gaseous phase after 500 s of simulation time

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