The study of heterogeneous two‐phase flow around small‐scale heterogeneity in porous sandstone by measured elastic wave velocities and lattice Boltzmann method simulation

Abstract

Two-phase fluid flow is strongly controlled by small-scale (subcore-scale) heterogeneity of porous sandstone. We monitor the heterogeneous/anisotropic two-phase flow (CO 2 and water) in porous sandstone and conduct multichannel V P and V P anisotropy measurements under super critical CO 2 conditions during CO 2 injection (drainage) and water reinjection (imbibition) processes. In drainage, V P shows large reduction (~10%) in all sections of the core sample and changes from the bottom inlet side to upper outlet side. It is considered that V P reduction reflects the CO 2 movement in the specimen. The V P anisotropy of the upper two planes indicates clear increase. The results of this experiment indicate the heterogeneous CO 2 flow around laminae in porous sandstone and characteristic behavior of these laminae as a barrier for CO 2 . On the other hand, flow of water is not affected by this barrier. This characteristic CO 2 water flow around laminae is observed in the numerical simulation results. This simulation study also indicates that the capillary number is not directly affected on two-phase fluid flow around small-scale heterogeneity in porous sandstone. These results suggest that the small-scale heterogeneity behaves as a CO 2 gate and strongly controls CO 2 behavior in porous sandstone.It is well known that fluid flow in porous sandstone is strongly affected by small-scale heterogeneity of sedimentary structures (millimeter to centimeter scale). In the case of multiphase fluid flow (e.g., N 2 , CO 2 , and brine), the nonwetting phase fluid (N 2 and CO 2 ) can show complex behavior. Recent studies have successfully KITAMURA ET AL. Key Points: • The gate effect of small-scale heterogeneity on CO 2 flow in porous sandstone • Monitoring of anisotropic CO 2 flow around lamina by V P and V P anisotropy • Water and CO 2 flow simulation by LBM in heterogeneous sandstone

Characterization of immiscible fluid displacement processes with various capillary numbers and viscosity ratios in 3D natural sandstone

“…The two-phase fluid behavior in porous media is influenced by many reservoir parameters, including the viscosity and density of the fluids, interfacial tension, pore structure, and other porous medium characteristics (e.g., wettability and surface roughness) (e.g., Al-Raoush, 2009;Nguyen et al, 2006;Wildenschild et al, 2011), all of which vary from one reservoir to the next. A number of numerical and experimental studies have been conducted to understand the complexities of multiphase fluid flow in porous media (e.g., Ahrenholz et al, 2008; ., 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 5 2011; Blunt et al, 2013;Cottin et al, 2010;Al-Housseiny et al, 2012;Homsy, 1987;Lehmann et al, 2008;Parmigiani et al, 2014;Weitz et al, 1987;Berg et al, 2013;Kazemifar et al, 2015a,b;Kitamura et al 2014;Setiawan et al, 2014). Lenormand et al (1988) demonstrated that the capillary number (Ca) and the viscosity ratio of a two-phase fluid (M) are the two most important factors…”

An efficient preconditioner for the fast simulation of a 2D stokes flow in porous media

“…Flow inside a porous medium finds many applications in natural and engineering systems. Subsurface flows,() erosion,() fuel cells, and filtration systems() are a few examples of physical processes that are governed by low Reynolds number porous media flow. Accurately resolving such flows is essential for modelling transport, mixing,() anomalous diffusion,() breakthrough curves, carbon dioxide sequestration,() uncertainty quantification of pore‐scale simulations,() chemical reactions,() and many other applications.…”

An efficient preconditioner for the fast simulation of a 2D Stokes flow in porous media

“…Flow inside a porous medium finds many applications in natural and engineering systems. Subsurface flows [1,2], erosion [3,4], fuel cells [5], and filtration systems [6,7] are a few examples of physical processes that are governed by low Reynolds number porous media flow. Accurately resolving such flows is essential for modelling transport [8], mixing [9,10], anomalous diffusion [11,12], breakthrough curves [13], carbon dioxide sequestration [14,15], uncertainty quantification [16,17], chemical reactions [18,19], and many other applications.…”

“…The quiver plot on the intake and outtake shows the pipe flow boundary conditions defined in Eq. (2).…”

“…Assuming the geometry is resolved and the density function is exact, the trapezoid rule results in machine precision if d(x, Γ) > √ ∆s 2. The error can be controlled and made as small as needed, however.…”