Predictive pore‐scale modeling of two‐phase flow in mixed wet media

Abstract

[1] We show how to predict flow properties for a variety of porous media using pore-scale modeling with geologically realistic networks. Starting with a network representation of Berea sandstone, the pore size distribution is adjusted to match capillary pressure for different media, keeping the rank order of pore sizes and the network topology fixed. Then predictions of single and multiphase properties are made with no further adjustment of the model. We successfully predict relative permeability and oil recovery for water wet, oil wet, and mixed wet data sets. For water flooding we introduce a method for assigning contact angles to match measured wettability indices. The aim of this work is not simply to match experiments but to use easily acquired data to predict difficult to measure properties. Furthermore, the variation of these properties in the field, due to wettability trends and different pore structures, can now be predicted reliably.

The Imaging of Dynamic Multiphase Fluid Flow Using Synchrotron-Based X-ray Microtomography at Reservoir Conditions

“…The controls on snap-off in arbitrarily complex geological media are difficult to understand. However, it is useful to consider the case of the hypothetical geometric elements (typically with triangular cross sections) present in network models (Valvatne and Blunt 2004). As capillary pressure decreases in these systems, the wetting phase present in the corner regions of elements swells until they come into contact.…”

“…where θ a is the advancing contact angle and β is the effective throat corner half-angle (Valvatne and Blunt 2004). The snap-off capillary pressure is therefore a function of throat size and shape, with smaller throats snapping off at higher capillary pressures than larger ones, and throat radius being the primary control on pore-throat snap-off capillary pressure (Andrew et al 2014a).…”

“…The main goal of our study is to identify individual dynamic drainage events at the porescale, at reservoir conditions, to advance our understanding of these phenomena, and in particular to test some of the assumptions of local capillarity and quasi-static flow used in the formulation of pore-scale network (Valvatne and Blunt 2004;Øren et al 1998) and direct simulation models (Raeini et al 2014a). Specifically, we observe persistent fluid configurations of trapped non-wetting phase, which cannot be explained by global capillary equilibrium concepts alone.…”

A forward analysis on the applicability of tracer breakthrough profiles in revealing the pore structure of tight gas sandstone and carbonate rocks

“…For instance, Mousavi and Bryant [2012] attempted to characterize tight gas sandstone rocks by performing cementation and compaction on sphere packs without the inclusion of microporosity, as well as distributing the measured pore and throat sizes on a network with single-scale topology. Although using a single-scale model has been successful in predicting the transport properties of conventional sandstones [Bryant et al, 1996;Øren and Bakke, 2002;Valvatne and Blunt, 2004;Joekar-Niasar and Hassanizadeh, 2012], significant errors ensued from their prediction of capillary pressure and relative permeability curves of tight gas sandstones.…”

Large-scale Invasion Percolation with Trapping for Upscaling Capillary-Controlled Darcy-scale Flow

“…Upon a closer look at the pore level, such a phase might be connected in thin layers (Valvatne and Blunt 2004). At larger scales, this layer flow might be neglected considering the timescale of the process (Blunt 2017).…”