Experimental study of cocurrent and countercurrent flows in natural porous media
TL;DR: In this article, the authors report flow experiments involving cocurrent and countercurrent spontaneous water/oil imbibition performed on the same laterally coated sample of a natural porous medium with local saturation measurements and various boundary conditions.
Abstract: This paper reports flow experiments involving cocurrent and countercurrent spontaneous water/oil imbibition performed on the same laterally coated sample of a natural porous medium with local saturation measurements and various boundary conditions. The experiments with countercurrent imbibition showed slower oil recovery, a smoother water/oil front, and slightly lower ultimate oil recovery than those with predominantly cocurrent imbibition. Numerical simulations revealed that the relative permeabilities that enabled good prediction of countercurrent oil recovery rate are about 30% less than the conventional cocurrent relative permeabilities at a given water saturation. Viscous coupling is assumed to be the origin of this difference. A new formulation of Darcy equations that uses a matrix of mobilities was found to be in qualitative agreement with experimental results.
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TL;DR: In this paper, a review of recent developments in the scaling of laboratory imbibition data is presented, with a focus on the development of surfactant-enhanced imbibitions.
Abstract: Spontaneous imbibition is of particular importance to oil recovery from fractured reservoirs. There has been a surge in the growth of technical literature over the past 5 years. This review is centered on developments in the scaling of laboratory imbibition data. Results for variation in interfacial tension, wetting and non-wetting phase viscosity, sample size, shape and boundary conditions, and initial wetting phase saturation have been correlated for a variety of strongly water-wet rocks as plots of normalized oil recovery vs. dimensionless time. Correlations have been tested for weakly water-wet conditions induced by adsorption from crude oil. In situ fluid saturation measurements have been used to distinguish between modes of imbibition that range from frontal to global displacement. Research on surfactant-enhanced imbibition has advanced from laboratory to field tests.
585 citations
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27 Mar 2017TL;DR: Multiphase Flow In Permeable Media Co Uk Martin J. Blunt and Je Santos Multiphaseporousmediapalabos Library.
Abstract: Hydrocarbon production, gas recovery from shale, CO2 storage and water management have a common scientific underpinning: multiphase flow in porous media. This book provides a fundamental description of multiphase flow through porous rock, with emphasis on the understanding of displacement processes at the pore, or micron, scale. Fundamental equations and principal concepts using energy, momentum, and mass balance are developed, and the latest developments in high-resolution three-dimensional imaging and associated modelling are explored. The treatment is pedagogical, developing sound physical principles to predict flow and recovery through complex rock structures, while providing a review of the recent literature. This systematic approach makes it an excellent reference for those who are new to the field. Inspired by recent research, and based on courses taught to thousands of students and professionals from around the world, it provides the scientific background necessary for a quantitative assessment of multiphase subsurface flow processes, and is ideal for hydrology and environmental engineering students, as well as professionals in the hydrocarbon, water and carbon storage industries.
427 citations
TL;DR: In this article, the effects of interfacial tension (IFT) changes and phase density difference on drainage and imbibition of oil/water/alcohol mixtures were investigated in four cores.
264 citations
TL;DR: A three-dimensional parallel processing version of a two-fluid-phase lattice Boltzmann model is used and a strong correlation between the relative permeability and interfacial area between fluids is found, indicating that both the common extension of Darcy's Law and the generalized formulation accounting for viscous coupling effects do not provide adequate insight into two-phase flow processes in porous media.
Abstract: Recent studies have revealed that viscous coupling effects in immiscible two-phase flow, caused by momentum transfer between the two fluid phases, can be important in porous medium systems. In this work, we use a three-dimensional parallel processing version of a two-fluid-phase lattice Boltzmann (LB) model to investigate this phenomenon. A multiple-relaxation-time (MRT) approximation of the LB equations is used in the simulator, which leads to a viscosity-independent velocity field. We validate our model by verifying the velocity profile for two-phase flow through a channel with a square cross section. We then simulate co-current flow through a sphere-pack porous medium and obtain correlations of the relative permeabilities as a function of capillary number, wettability, and the fluid viscosities. The results are qualitatively consistent with experimental observations. In addition, we calculate the generalized permeability coefficients and show that the coupling coefficients are significant and the matrix is nonsymmetric. We also find a strong correlation between the relative permeability and interfacial area between fluids, indicating that both the common extension of Darcy's Law and the generalized formulation accounting for viscous coupling effects do not provide adequate insight into two-phase flow processes in porous media. This work lends additional support for the hypothesis that interfacial area is a key variable for multiphase flow in porous medium systems.
221 citations
TL;DR: In this article, it is shown that when a matrix block is partia covered by water, oil recovery is dominated by cocurrent imbibition, not countercurrent, and it is also found that the time for a spe fied recovery by the former can be much smaller than that countercurrent imbibion.
Abstract: er, Summary Imbibition in water-wet matrix blocks of fractured porous med is commonly considered to be countercurrent. The modeling s ies of this paper indicate that when a matrix block is partia covered by water, oil recovery is dominated by cocurrent imb tion, not countercurrent. It is also found that the time for a spe fied recovery by the former can be much smaller than that countercurrent imbibition. Consequently, use of the imbibiti data by immersing a single block in water and its scale-up m provide pessimistic recovery information. Moreover, it is sho that the application of the diffusion equation for modeling of recovery by cocurrent imbibition leads to a large error. Throug detailed study of the governing equations and boundary co tions, significant insight is provided into the mathematical a physical differences between coand countercurrent imbibitio
189 citations