A distributed parallel direct simulator for pore-scale two-phase flow on digital rock images using a finite difference implementation of the phase-field method

2018 ◽  
Vol 166 ◽  
pp. 806-824 ◽  
Author(s):  
Faruk Alpak ◽  
Aleksandar Samardžić ◽  
Florian Frank
2020 ◽  
Author(s):  
Huhao Gao ◽  
Alexandru Tatomir ◽  
Nikolaos Karadimitriou ◽  
Martin Sauter

<p>Over the last few years, our understanding of the processes involved in the application of Kinetic Interfacial Sensitive (KIS) tracers in two-phase flow as a means to quantify the fluid-fluid interfacial area has been enhanced with the use of controlled column experiments (Tatomir et al. 2015,2018). However, there are still some open questions regarding the effect of immobile water, either as capillary and dead-end trapped water or as a film, and the measured by product concentration at the outflow.</p><p>In this study, a new pore-scale reactive transport model is presented, based on the phase-field method, which is able to deal with the KIS tracer interfacial reaction and selective distribution of the by-production into the water phase. The model is validated by comparing the analytical solutions for a diffusion process across the interface and a reaction-diffusion process, and is tested for a drainage process in a capillary tube for different Péclet numbers. The applicability of the model is demonstrated in a realistic 2D porous medium NAPL/water drainage scenario used in the literature. Four case studies are investigated in detail to obtain macroscopic parameters, like saturation, capillary pressure, specific interfacial area, and concentration, for a number of combinations between the inflow rate, the contact angle and diffusivity. We derive a relation between the by-product mass at the outflow and the mobile part of the interfacial area, which is formulated by adding a residual factor. This term relates to the part of the by-product produced by mobile interface that becomes residual in the immobile zones.</p>


2018 ◽  
Vol 108 ◽  
pp. 169-180 ◽  
Author(s):  
Nazia Talat ◽  
Boštjan Mavrič ◽  
Grega Belšak ◽  
Vanja Hatić ◽  
Saša Bajt ◽  
...  

SPE Journal ◽  
2018 ◽  
Vol 23 (05) ◽  
pp. 1833-1850 ◽  
Author(s):  
Florian Frank ◽  
Chen Liu ◽  
Faruk O. Alpak ◽  
Steffen Berg ◽  
Beatrice Riviere

Summary Advances in pore-scale imaging, increasing availability of computational resources, and developments in numerical algorithms have started rendering direct pore-scale numerical simulations of multiphase flow on pore structures feasible. In this paper, we describe a two-phase-flow simulator that solves mass- and momentum-balance equations valid at the pore scale (i.e., at scales where the Darcy velocity homogenization starts to break down). The simulator is one of the key components of a molecule-to-reservoir truly multiscale modeling work flow. A Helmholtz free-energy-driven, thermodynamically based diffuse-interface/phase-field method is used for the effective simulation of numerous advecting interfaces, while honoring the interfacial tension (IFT). The advective Cahn-Hilliard (CH) (mass-balance, energy dissipation) and Navier-Stokes (NS) (momentum-balance, incompressibility) equations are coupled to each other within the phase-field framework. Wettability on rock/fluid interfaces is accounted for by means of an energy-penalty-based wetting (contact-angle) boundary condition. Individual balance equations are discretized by use of a flexible discontinuous Galerkin (DG) method. The discretization of the mass-balance equation is semi-implicit in time using a convex/concave splitting of the energy term. The momentum-balance equation is split from the incompressibility constraint by a projection method and linearized with a Picard splitting. Mass- and momentum-balance equations are coupled to each other by means of operator splitting, and are solved sequentially. We discuss the mathematical model and its DG discretization, and briefly introduce nonlinear and linear solution strategies. Numerical-validation tests show optimal convergence rates for the DG discretization, indicating the correctness of the numerical scheme and its implementation. Physical-validation tests demonstrate the consistency of the phase distribution and velocity fields simulated within our framework. Finally, two-phase-flow simulations on two real pore-scale images demonstrate the usefulness of the pore-scale simulator. The direct pore-scale numerical-simulation methodology rigorously considers the flow physics by directly acting on pore-scale images of rocks without remeshing. The proposed method is accurate, numerically robust, and exhibits the potential for tackling realistic problems.


2019 ◽  
Vol 397 ◽  
pp. 108832 ◽  
Author(s):  
Zhicheng Wang ◽  
Suchuan Dong ◽  
Michael S. Triantafyllou ◽  
Yiannis Constantinides ◽  
George Em Karniadakis

2018 ◽  
Vol 100 ◽  
pp. 77-85
Author(s):  
Keunsoo Park ◽  
Maria Fernandino ◽  
Carlos A. Dorao

2021 ◽  
Author(s):  
Alan Junji Yamaguchi ◽  
Kaito Kobayashi ◽  
Toru Sato ◽  
Takaomi Tobase

Abstract The global warming is an important environmental concern and the carbon capture and storage (CCS) emerges as a very promising technology. Captured carbon dioxide (CO2) can be stored onshore or offshore in the aquifers. There is, however, a risk that stored CO2 will leak due to natural disasters. One possible solution to this is the natural formation of CO2 hydrates. Gas hydrate has an ice-like structure in which small gas molecules are trapped within cages of water molecules. Hydrate formation occurs under high pressure and low temperature conditions. Its stability under these conditions acts like a cap rock to prevent CO2 leaks. The main objective of this study is to understand how hydrate formation affects the permeability of leaked CO2 flows. The phase field method was used to simulate microscopic hydrate growth within the pore space of sand grains, while the lattice Boltzmann method was used to simulate two-phase flow. The results showed that the hydrate morphology within the pore space changes with the flow, and the permeability is significantly reduced as compared with the case without the flow.


Author(s):  
Ehsan Sabooniha ◽  
Mohammad-Reza Rokhforouz ◽  
Shahab Ayatollahi

Biotechnology has had a major effect on improving crude oil displacement to increase petroleum production. The role of biopolymers and bio cells for selective plugging of production zones through biofilm formation has been defined. The ability of microorganisms to improve the volumetric sweep efficiency and increase oil recovery by plugging off high-permeability layers and diverting injection fluid to lower-permeability was studied through experimental tests followed by multiple simulations. The main goal of this research was to examine the selective plugging effect of hydrophobic bacteria cell on secondary oil recovery performance. In the experimental section, water and aqua solution of purified Acinetobacter strain RAG-1 were injected into an oil-saturated heterogeneous micromodel porous media. Pure water injection could expel oil by 41%, while bacterial solution injection resulted in higher oil recovery efficiency; i.e., 59%. In the simulation section, a smaller part of the heterogeneous geometry was employed as a computational domain. A numerical model was developed using coupled Cahn–Hilliard phase-field method and Navier–Stokes equations, solved by a finite element solver. In the non-plugging model, approximately 50% of the matrix oil is recovered through water injection. Seven different models, which have different plugging distributions, were constructed to evaluate the influences of selective plugging mechanism on the flow patterns. Each plugging module represents a physical phenomenon which can resist the displacing phase flow in pores, throats, and walls during Microbial-Enhanced Oil Recovery (MEOR). After plugging of the main diameter route, displacing phase inevitably exit from sidelong routes located on the top and bottom of the matrix. Our results indicate that the number of plugs occurring in the medium could significantly affect the breakthrough time. It was also observed that increasing the number of plugging modules may not necessarily lead to higher ultimate oil recovery. Furthermore, it was shown that adjacent plugs to the inlet caused flow patterns similar to the non-plugging model, and higher oil recovery factor than the models with farther plugs from the inlet. The obtained results illustrated that the fluids distribution at the pore-scale and the ultimate oil recovery are strongly dependent on the plugging distribution.


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