scholarly journals Analysis of CT-Measured Pore Characteristics of Porous Media Relative to Physical Properties

2016 ◽  
Vol 95 ◽  
pp. 442-449 ◽  
Author(s):  
P. Adhikari ◽  
S.H. Anderson ◽  
R.P. Udawatta ◽  
S. Kumar
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Pore Characteristics

Foam Flow in Different Pore Systems—Part 2: The Roles of Pore Attributes on the Limiting Capillary Pressure, Trapping Coefficient, and Relative Permeability of Foamed Gas

SPE Journal ◽  
2021 ◽  
pp. 1-23
Author(s):  
Abdulrauf Rasheed Adebayo
Keyword(s):  
Porous Media ◽  
Capillary Pressure ◽  
Relative Permeability ◽  
Average Pore Size ◽  
Volume Ratio ◽  
Graphical Analysis ◽  
Pore Characteristics ◽  
Average Pore ◽  
Rock Samples ◽  
Foam Properties

Summary The limiting capillary pressure of foam (Pc*) and foam trapping in porous media are pore-scale foam properties that affect foam transport in porous media. They are strongly influenced by the characteristics of rock pores and throats. Because of experimental limitations, these foam properties are difficult to measure at core scale. As a result, our understanding of their relationship with different pore characteristics is limited. In this paper, novel coreflood and graphical analysis techniques were used to measure Pc* and the foam-trapping coefficient (FTC) at core scale. FTC is a new parameter synonymous to Land’s (1968) trapping coefficient, which describes foam-trapping behavior across an entire range of saturation as opposed to a single endpoint trapped saturation. The scalability of these two foam properties with permeability and other pore characteristics [average pore size (PS), average throat size (TS), average aspect ratio (AR), coordination number (CN), surface area/volume ratio, and reservoir-quality index (RQI)] were also investigated. Pore characteristics of 12 different rock samples were measured from 3D pore-network models generated from high-resolution X-raycomputed-microtomography images. The heterogeneity of the rock samples were quantified by the Dykstra-Parsons index (Dysktra and Parsons 1950), while the RQI and J-function methods were used to classify them according to their storage and flow properties. Each of the measured pore characteristics and their combination [combined pore character (CPC)] were then correlated with Pc* and FTC to understand their respective roles. Furthermore, the data points obtained from the graphical analysis of the coreflood data provided the required input data for a mechanistic foam model for relative permeability of foamed gas (Kovscek and Radke 1994). The estimated relative permeability of foamed gas was then used to study foam mobility in the different pore geometries. The overall results showed the following: P c * has strong negative correlations with all pore characteristics except AR, which has a weak positive correlation. P c * has the strongest correlation with RQI, CPC, and permeability; a moderate correlation with CN and TS; and a very weak correlation with PS. Foam trapping has positive correlations with all pore characteristics except AR, which has a negative correlation. Low AR appears to be responsible for significant trapping of foam in high-permeabilityrocks. Low AR favors more foam trapping, while high AR favors trapping of oil and gas during water imbibition in water-wetrocks. Foam trapping appears to have the dominant control on foam mobility.

Numerical Model of Complex Porous Media

2002 ◽  
Author(s):  
Andre´ Chambarel ◽  
Herve´ Bolvin
Keyword(s):  
Porous Media ◽  
Numerical Model ◽  
Physical Properties ◽  
Space Distribution ◽  
Partial Differential ◽  
Differential Problem ◽  
Classical Models ◽  
Element Approach ◽  
Statistical Approaches ◽  
Percolation Phenomenon

In complex porous media we often notice a percolation phenomenon [KIR 71] [GRI 89]. Usually these media present discontinuous characteristics and a random space distribution [LET 00] [BIR 95]. There results that the classical models based on the resolution of a partial differential problem become inefficient because we have non-derivable function [MAU 01]. Statistical approaches based on the resolution of partial differential problems pose notably the questions concerning the continuity of the functions representing the physical properties of the medium. In this work we propose to study a numerical model of porous media based on a mixture of 2 components in a percolation context. In practice, the main difficulty is based on the complex physical properties. We present also a model of homogenization. Our numerical model is based on the Finite Element approach.

Moisture Effective Diffusivity in Porous Media with Different Physical Properties

2006 ◽  
Vol 258-260 ◽  
pp. 207-212
Author(s):  
Miranda M.N.N. ◽  
M.A. Silva
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Moisture Content ◽  
Mass Transport ◽  
Physical Properties ◽  
Pore Size ◽  
Structural Properties ◽  
Effective Diffusivity ◽  
Nay Zeolite ◽  
Moisture Effective Diffusivity

In the drying of porous media, the mass transport occurs in the pores as well as on the surface of the solid. The mechanisms involved can take place simultaneously, influenced by the predominant one and can change depending on the moisture content. In this work, the moisture effective diffusivity was estimated in solids with distinct structural properties in order to verify the predominant mechanisms according to the moisture content, analyzing the influence of the physical properties. The materials studied were NaY Zeolite, Kaolin, Silica and Alumina. The results of diffusion coefficient present a minimum at low moisture content that can be related to pore size.

scholarly journals Dryout and Replenishment of Bottom-Heated Saturated Porous Media with an Overlying Plain Water Layer

2018 ◽  
Vol 8 (12) ◽  
pp. 2607
Author(s):  
Montserrat Carbonell ◽  
Luis Virto ◽  
Pedro Gamez-Montero
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Thermal State ◽  
Water Layer ◽  
Coarse Sand ◽  
Solid Matrix ◽  
Plain Water ◽  
Liquid Phases ◽  
State Evolution ◽  
The Stability

The aim of this paper is to elucidate the influence of the physical properties of both phases—solid matrix and saturating liquid—of bottom-heated porous media with an overlying plain water layer. The dryout, the stability of the system’s water layer-vapor region, and the thermal state evolution are studied. The porous media under study are a bronze powder saturated by water, and a solution of surfactant and coarse sand saturated by the same liquids. From the experimental data obtained, a theoretical approach is carried out to describe the dryout and rewetting process. The influence of the nature and physical properties of the solid and liquid phases is also analyzed, with special attention to the addition of surfactant in the saturating liquid.

A Pore-Scale Reactive Transport Model Approach for Investigating the Effect of Soil Physical Properties on Biogeochemical Processes

2020 ◽  
Author(s):  
Amir Golparvar ◽  
Matthias Kästner ◽  
Martin Thullner
Keyword(s):  
Porous Media ◽  
Physical Properties ◽  
Vadose Zone ◽  
Reactive Transport ◽  
Soil Physical Properties ◽  
Transport Processes ◽  
Biogeochemical Processes ◽  
Pore Scale ◽  
Model Approach

<p>The vadose zone hosts a wide range of various microorganisms which provide different soil ecosystem services from nutrient cycling to biodegradation of harmful chemical substances. The efficiency of such in-situ biodegradation is influenced by different biotic and abiotic factors ranging from physical properties of the soil to the redox conditions controlled by the activity of the involved chemical compounds. One important feature of the soil system is the dynamical and simultaneous interplay of these factors, boosting or deteriorating the residing microbial community’s abundance and/or activity and hence shaping biodegradation of vadose zone contaminants. Physical properties of porous media – e.g. the pore geometry, pore size distribution, connectivity as well as the water content – play a major role in enhancing or restricting the bioavailable concentration of contaminants and other reaction partners. Pore-scale phenomena have been shown to be considerably affecting the macro-scale processes, therefore a quantitative bottom-top approach of these mechanisms in situ is adamant. Hence it is of paramount importance to understand the effect of soil physical properties on microbial activity and biodegradation of carbon compounds in soil.</p><p>Pore scale reactive transport processes have a complex, nonlinear dependency on the aforementioned factors, which severely challenges the experimental and/or numerical investigation of biodegradation at in in-situ conditions. However, the recent technological advances, specifically the imaging techniques, have made it easier to study biological and microbial evolution in porous media, but there is still a need for putting all these information together. For this purpose, numerical methods would offer the possibility of simulating a variable/controllable water saturation conditions and considering water/air dynamics and advective and diffusive micro-scale transport of all components in both, air and water phase, in porous medium structures directly obtained from CT scanned samples. Up to now, such pore-sale model approaches considering also the fate of biogeochemically reactive compounds are scarce. In this work we propose a novel reactive transport modelling technique combining the pore-scale numerical characterization of water flow and solute transport in unsaturated porous media and of biogeochemical process. For a variably saturated porous system, the presented model approach is solving the Navier Stokes equation and scalar transport equations for any arbitrary geometry and is simulating the dynamics of biogeochemical processes with any degree of complexity. Simulations are compared to experimental data to assess the effect of soil physical properties on the transport and degradation of contaminants in soil.</p>

scholarly journals Laboratory Measurement and Interpretation of the Changes of Physical Properties after Heat Treatment in Tight Porous Media

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yili Kang ◽  
Mingjun Chen ◽  
Lijun You ◽  
Xiangchen Li
Keyword(s):  
Heat Treatment ◽  
Porous Media ◽  
Physical Properties ◽  
Gas Production ◽  
Treatment Temperature ◽  
High Temperature Treatment ◽  
Tight Gas ◽  
Tight Sandstone ◽  
Structure Generation ◽  
Tight Porous Media

Prevention of water blocking and optimization of multiscale flow channels will increase gas production of tight reservoirs. Physical properties of samples from representative tight gas reservoirs were measured before and after high temperature treatment. Results show that, with the increase of treatment temperature, mass decreases, acoustic transit time increases, and permeability and porosity increase. Permeability begins to increase dramatically if treatment temperature exceeds the threshold value of thermal fracturing, which is 600~700°C, 500~600°C, 300~500°C, and 300~400°C for shale, mudstone, tight sandstone, and tight carbonate rock, respectively. Comprehensive analyses indicate that the mechanisms of heat treatment on tight porous media include evaporation and dehydration of water, change of mineral structure, generation of microfracture, and network connectivity. Meanwhile, field implementation is reviewed and prospected. Interpretations indicate that, according to the characteristics of multiscale mass transfer in tight gas formation, combining heat treatment with conventional stimulation methods can achieve the best stimulation result.

Suboptimal fertilisation compromises soil physical properties of a hard-setting sandy loam

Soil Research ◽  
2017 ◽  
Vol 55 (4) ◽  
pp. 332 ◽  
Author(s):  
Johannes Lund Jensen ◽  
Per Schjønning ◽  
Bent T. Christensen ◽  
Lars Juhl Munkholm
Keyword(s):  
Physical Properties ◽  
Crop Residues ◽  
Nutrient Management ◽  
Sandy Loam ◽  
Animal Manure ◽  
Crop Productivity ◽  
Soil Physical Properties ◽  
Pore Characteristics ◽  
The Impact

Nutrient management affects not only crop productivity and environmental quality, but also soil physical properties related to soil tilth. Previous studies on soil physical properties have focussed on effects of fertiliser type, whereas the effect of fertiliser rate has been neglected. We examined the impact of no fertilisation (UNF) and different rates of mineral fertiliser (½NPK and 1NPK) and animal manure (1½AM) on an ensemble of soil physical characteristics, with the amount of fertiliser added at level 1 corresponding to the standard rate of plant nutrients for a given crop. Soil was from the Askov long-term field experiment, initiated in 1894 on a hard-setting sandy loam. We assessed clay dispersibility, wet-stability of aggregates, aggregate strength, bulk soil strength and soil pore characteristics. The soils receiving 1NPK and 1½AM had similar soil physical properties, the only differences being a wider range in the optimum water content for tillage and more plant-available water in the soil amended with 1½AM. Suboptimal fertiliser rates (UNF and ½NPK) increased clay dispersibility, soil cohesion and bulk density, and reduced aggregate stability. The physical properties of soils exposed to suboptimal fertilisation indicate that the level of soil organic matter, including active organic binding and bonding materials, has become critically low due to reduced inputs of crop residues. While long-term suboptimal fertilisation compromises soil physical properties, crop-yield-optimised rates of mineral fertilisers and animal manure appear to sustain several soil physical properties equally well.

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