Flow behavior and residual saturation formation of liquid carbon tetrachloride in unsaturated heterogeneous porous media

In this work,we present three-dimensional numerical simulations of water-oil ﬂow in porous media in order to analyze the inﬂuence of the heterogeneities in the porosity and permeability ﬁelds and, mainly, their relationships upon the phenomenon known in the literature as viscous ﬁngering. For this, typical scenarios of heterogeneous reservoirs submitted to water injection (secondary recovery method) are considered. The results show that the porosity heterogeneities have a markable inﬂuence in the ﬂow behavior when the permeability is closely related with porosity, for example, by the Kozeny-Carman (KC) relation.This kind of positive relation leads to a larger oil recovery, as the areas of high permeability(higher ﬂow velocities) are associated with areas of high porosity (higher volume of pores), causing a delay in the breakthrough time. On the other hand, when both ﬁelds (porosity and permeability) are heterogeneous but independent of each other the inﬂuence of the porosity heterogeneities is smaller and may be negligible.

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Complexity Reduction of Multiphase Flows in Heterogeneous Porous Media

SPE Journal ◽

10.2118/167295-pa ◽

2016 ◽

Vol 21 (01) ◽

pp. 144-151 ◽

Cited By ~ 11

Author(s):

Mehdi Ghommem ◽

Eduardo Gildin ◽

Mohammadreza Ghasemi

Keyword(s):

Porous Media ◽

Model Reduction ◽

Flow Behavior ◽

Computational Cost ◽

Heterogeneous Porous Media ◽

Production Optimization ◽

Dynamic Mode ◽

Two Phase ◽

Fine Grid ◽

Mode Decomposition

Summary In this paper, we apply mode decomposition and interpolatory projection methods to speed up simulations of two-phase flows in heterogeneous porous media. We propose intrusive and nonintrusive model-reduction approaches that enable a significant reduction in the size of the subsurface flow problem while capturing the behavior of the fully resolved solutions. In one approach, we use the dynamic mode decomposition. This approach does not require any modification of the reservoir simulation code but rather post-processes a set of global snapshots to identify the dynamically relevant structures associated with the flow behavior. In the second approach, we project the governing equations of the velocity and the pressure fields on the subspace spanned by their proper-orthogonal-decomposition modes. Furthermore, we use the discrete empirical interpolation method to approximate the mobility-related term in the global-system assembly and then reduce the online computational cost and make it independent of the fine grid. To show the effectiveness and usefulness of the aforementioned approaches, we consider the SPE-10 benchmark permeability field, and present a numerical example in two-phase flow. One can efficiently use the proposed model-reduction methods in the context of uncertainty quantification and production optimization.

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Pore-Scale Simulations of CO2/Oil Flow Behavior in Heterogeneous Porous Media under Various Conditions

Energies ◽

10.3390/en14030533 ◽

2021 ◽

Vol 14 (3) ◽

pp. 533

Author(s):

Qingsong Ma ◽

Zhanpeng Zheng ◽

Jiarui Fan ◽

Jingdong Jia ◽

Jingjing Bi ◽

...

Keyword(s):

Porous Media ◽

Oil Recovery ◽

Flow Behavior ◽

Heterogeneous Porous Media ◽

Co2 Injection ◽

Injection Velocity ◽

Recovery Efficiency ◽

Small Pore ◽

Miscible Flooding ◽

Oil Flow

Miscible and near-miscible flooding are used to improve the performance of carbon-dioxide-enhanced oil recovery in heterogeneous porous media. However, knowledge of the effects of heterogeneous pore structure on CO2/oil flow behavior under these two flooding conditions is insufficient. In this study, we construct pore-scale CO2/oil flooding models for various flooding methods and comparatively analyze CO2/oil flow behavior and oil recovery efficiency in heterogeneous porous media. The simulation results indicate that compared to immiscible flooding, near-miscible flooding can increase the CO2 sweep area to some extent, but it is still inefficient to displace oil in small pore throats. For miscible flooding, although CO2 still preferentially displaces oil through big throats, it may subsequently invade small pore throats. In order to substantially increase oil recovery efficiency, miscible flooding is the priority choice; however, the increase of CO2 diffusivity has little effect on oil recovery enhancement. For immiscible and near-miscible flooding, CO2 injection velocity needs to be optimized. High CO2 injection velocity can speed up the oil recovery process while maintaining equivalent oil recovery efficiency for immiscible flooding, and low CO2 injection velocity may be beneficial to further enhancing oil recovery efficiency under near-miscible conditions.

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