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Impact of interfacial tension on residual CO 2 clusters in porous sandstone
Author(s) -
Jiang Fei,
Tsuji Takeshi
Publication year - 2015
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1002/2014wr016070
Subject(s) - surface tension , porous medium , lattice boltzmann methods , materials science , residual , residual oil , imbibition , cluster (spacecraft) , capillary action , mechanics , porosity , dissolution , capillary pressure , trapping , saturation (graph theory) , composite material , mineralogy , geology , petroleum engineering , chemical engineering , thermodynamics , physics , computer science , mathematics , algorithm , engineering , biology , germination , programming language , botany , combinatorics , ecology
We develop a numerical simulation that uses the lattice Boltzmann method to directly calculate the characteristics of residual nonwetting‐phase clusters to quantify capillary trapping mechanisms in real sandstone. For this purpose, a digital‐rock‐pore model reconstructed from micro‐CT‐scanned images of Berea sandstone is filtered and segmented into a binary file. The residual‐cluster distribution is generated following simulation of the drainage and imbibition processes. The characteristics of the residual cluster in terms of size distribution, major length, interfacial area, and sphericity are investigated under conditions of different interfacial tension (IFT). Our results indicate that high interfacial tension increases the residual saturation and leads to a large size distribution of residual clusters. However, low interfacial tension results in a larger interfacial area, which is beneficial for dissolution and reaction processes during geological carbon storage. Analysis of the force balance acting on the residual clusters demonstrates that trapping stability is higher in high interfacial tension case, and the interfacial tension should be a controlling factor for the trapping stability in addition to the pore geometry and connectivity. The proposed numerical method can handle the complex displacement of multicomponent systems in porous media. By using this method, we can obtain residual‐cluster distributions under different conditions for optimizing the storage capacity of carbon‐storage projects.