scholarly journals Effective Diffusion in Fibrous Porous Media: A Comparison Study between Lattice Boltzmann and Pore Network Modeling Methods

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 756
Author(s):  
Xiang Huang ◽  
Wei Zhou ◽  
Daxiang Deng
Keyword(s):  
Structural Properties ◽  
Lattice Boltzmann ◽  
Diffusion Coefficients ◽  
Network Modeling ◽  
Effective Diffusion ◽  
Pore Network ◽  
Pore Scale ◽  
Virtual Design ◽  
Equivalent Radius ◽  
Pore Network Modeling

The understanding of the correlation between a pore-scale structure and its coupled diffusion transport property is crucial in the virtual design and performance optimization of porous fibrous material for various energy applications. Two most common and widely employed pore-scale modeling techniques are the lattice Boltzmann method (LBM) and the pore network modeling (PNM). However, little attention has been paid to the direct comparison between these two methods. To this end, stochastic porous fibrous structures are reconstructed reflecting the structural properties of the fibrous porous material on a statistical level with structural properties obtained from X-ray computed microtomography. Diffusion simulation through the porous phase was subsequently conducted using LBM of D3Q7 lattice and topological equivalent PNM derived from the watershed method, respectively. It is detected that the effective diffusion coefficients between these two methods are in good agreement when the throat radius in the pore network is estimated using the cross-section area equivalent radius. Like most literature, the diffusivity in the in-plane (IP) direction is larger than in the through-plane (TP) direction due to the laid fiber arrangement, but the values are very close. Besides, tortuosity was evaluated from both geometry and transport measurements. Tortuosity values deduced from both methods are in line with the anisotropy of the diffusion coefficients.

scholarly journals Validation of pore network modeling for determination of two-phase transport in fibrous porous media

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Xiang Huang ◽  
Wei Zhou ◽  
Daxiang Deng
Keyword(s):  
Porous Media ◽  
Capillary Pressure ◽  
Network Modeling ◽  
Pore Network ◽  
Lattice Boltzmann Model ◽  
Two Phase ◽  
Throat Radius ◽  
Equivalent Radius ◽  
Pore Network Modeling ◽  
The Cost

AbstractPore network modeling (PNM) has been widely investigated in the study of multiphase transport in porous media due to its high computational efficiency. The advantage of PNM is achieved in part at the cost of using simplified geometrical elements. Therefore, the validation of pore network modeling needs further verification. A Shan-Chen (SC) multiphase lattice Boltzmann model (LBM) was used to simulate the multiphase flow and provided as the benchmark. PNM using different definitions of throat radius was performed and compared. The results showed that the capillary pressure and saturation curves agreed well when throat radius was calculated using the area-equivalent radius. The discrepancy of predicted phase occupations from different methods was compared in slice images and the reason can be attributed to the capillary pressure gradients demonstrated in LBM. Finally, the relative permeability was also predicted using PNM and provided acceptable predictions when compared with the results using single-phase LBM.

Multiscale Reconstruction of Vuggy Carbonates by Pore-Network Modeling and Image-Based Technique

SPE Journal ◽  
2019 ◽  
Vol 25 (01) ◽  
pp. 253-267 ◽  
Author(s):  
Saeid Sadeghnejad ◽  
Jeff Gostick
Keyword(s):  
Flow Behavior ◽  
Network Modeling ◽  
Pore Network ◽  
Absolute Permeability ◽  
Pore Network Model ◽  
Pore Scale ◽  
Secondary Porosity ◽  
Pore Network Modeling ◽  
Carbonate Formation ◽  
The Absolute

Summary Vugular carbonate rocks have a complicated flow behavior because of their multimodal porosity system, with different interconnectivity at the pore scale. In this study, a new hybrid algorithm to reconstruct a bimodal vugular porous medium is introduced by coupling the pore-network modeling approach (i.e., stochastic) with the image-based network technique (i.e., process-based). This work implements image-processing techniques to generate a lattice-based network of secondary porosity (i.e., vugs) on top of an initial pore-network model at the pore scale. The resulting multiscale model is designed to preserve vug-to-vug and vug-to-pore connectivity of overlapping vugs. Modifying the effective conductance of the overlapped vugs enables the calculation of permeability of the dual-porosity network by applying mass conservation and the Poiseuille law. The method is validated on samples from an Iranian carbonate formation. The matrix micropores obtained from the mercury-intrusion laboratory measurements are statistically reconstructed by a Nelder-Mead optimization algorithm. Our results show that during the addition of vugs into a network, the absolute permeability of the network increases monotonically with rising porosity before vug percolation. However, once vuggy pores percolate, the absolute permeability of the network increases tremendously. Moreover, the availability of vugs makes the network structure more complex as determined by the off-diagonal complexity measure. The results of this study help in understanding the behavior of vuggy formations observed in carbonate reservoirs.

Pore Network Modeling of a Polymer Flooding Microscopic Seepage Mechanism

2011 ◽  
Vol 29 (17) ◽  
pp. 1803-1810 ◽  
Author(s):  
C. Z. Sun ◽  
H. Q. Jiang ◽  
J. J. Li ◽  
S. J. Ye
Keyword(s):  
Network Modeling ◽  
Pore Network ◽  
Polymer Flooding ◽  
Pore Network Modeling

Relationship between Residual Saturations and Wettability using Pore-Network Modeling

2021 ◽  
Author(s):  
Prakash Purswani ◽  
Russell T. Johns ◽  
Zuleima T. Karpyn
Keyword(s):  
Contact Angle ◽  
Oil Recovery ◽  
Network Modeling ◽  
Pore Network ◽  
Residual Oil ◽  
Residual Saturation ◽  
Oil Saturation ◽  
Pore Network Modeling ◽  
Residual Oil Saturation ◽  
Eor Processes

Abstract The relationship between residual saturation and wettability is critical for modeling enhanced oil recovery (EOR) processes. The wetting state of a core is often quantified through Amott indices, which are estimated from the ratio of the saturation fraction that flows spontaneously to the total saturation change that occurs due to spontaneous flow and forced injection. Coreflooding experiments have shown that residual oil saturation trends against wettability indices typically show a minimum around mixed-wet conditions. Amott indices, however, provides an average measure of wettability (contact angle), which are intrinsically dependent on a variety of factors such as the initial oil saturation, aging conditions, etc. Thus, the use of Amott indices could potentially cloud the observed trends of residual saturation with wettability. Using pore network modeling (PNM), we show that residual oil saturation varies monotonically with the contact angle, which is a direct measure of wettability. That is, for fixed initial oil saturation, the residual oil saturation decreases monotonically as the reservoir becomes more water-wet (decreasing contact angle). Further, calculation of Amott indices for the PNM data sets show that a plot of the residual oil saturation versus Amott indices also shows this monotonic trend, but only if the initial oil saturation is kept fixed. Thus, for the cases presented here, we show that there is no minimum residual saturation at mixed-wet conditions as wettability changes. This can have important implications for low salinity waterflooding or other EOR processes where wettability is altered.

scholarly journals Pore-network modeling and determination of rock and two-phase fluid flow properties

2021 ◽  
Vol 143 (3) ◽  
pp. 106-114
Author(s):  
Zh.K. Akasheva ◽  
◽  
D.A. Bolysbek ◽  
B.K. Assilbekov ◽  
A.K. Yergesh ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Network Modeling ◽  
Pore Network ◽  
Flow Properties ◽  
Two Phase ◽  
Pore Network Modeling ◽  
Phase Fluid
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