Wide Range Of Permeability Values Research Articles

Well production after hydraulic fracturing in sandstone rocks in the north of the Perm region

Hydraulic fracturing is one of the most popular ways of increasing well production. The article investigates the results of hydraulic fracturing (HF) in sandstones of the northern Perm region territory (Tula–Bobrikovian oil reservoirs of the Visean stage). The oil of these sites has a high and medium gas content, and the rocks have a wide range of permeability values as well as natural cracking. Based on the value of the linear Spearman correlation coefficient, the most significant parameters affecting the efficiency of the HF are determined. A ranking of these parameters has been performed. The greatest influence on well productivity after HF is the bottomhole pressure and productivity indices before HF. The relationships between the geometrical dimensions of HF cracks and the volume of the injected proppant are shown. The dependencies of well parameters after HF on well parameters before HF are constructed. The permeability coefficients of the reservoir remote zone do not actually change much after HF and the permeability coefficients of the bottom-hole zone increase on average by 30%. The impact of the formation and bottomhole pre ssure values on productivity indices after HF has been noted. At the same time, the rate of oil production decrease after HF is also dependent on bottomhole pressures. Recommendations have been made on the selection of wells for HF at the site under study and similar production targets as well as their post-operation technology practices. Changes in well production after HF are forecasted depending on geological and technological parameters. The study was supported by the Russian Science Foundation, Project No. 19-79-10034.

Mechanistic foam flow model with variable flowing foam fraction and its implementation using automatic differentiation

Foam injection is an effective method for modifying gas mobility in subsurface flow applications making it ideal for environmental remediation applications. Remediation of contaminated soils/aquifers of nonaqueous phase liquids using foamed surfactant solutions is a viable option but a predictive foam model is needed that is flexible to the addition of more accurate physical descriptions. Such a model is essential to ensure successful operations in soil remediation applications. The objective of this paper is to develop a full-physics, mechanistic transient foam flow model and integrate it into the multiphysics, modular AD-GPRS framework (Automatic Differentiation–General Purpose Research Simulator). We chose AD-GPRS because it allows rapid prototyping and addition of complex physics and modeling strategies. We develop the model ground-up from pore-scale observations and implement a new flowing foam fraction constitutive relation that depends on the local pressure gradient, local permeability, and flowing bubble density. Our model predicts the two flow regimes commonly observed in steady-state pressure gradient measurements: the low-quality regime and the high-quality regime. Additionally, the model is used to match transient experimental results of homogeneous and slightly heterogeneous cores with a wide range of permeability values. The implementation of this model within AD-GPRS allows testing of ideas and modeling strategies as well as inclusion of more complex physics or foam generation kinetics.

Effects of hydrophobicity and molecular weight on the transport permeability of oligopeptides across Caco‐2 cell monolayers

The objective of this paper was to investigate the effects of hydrophobicity and molecular weight (MW) on the transepithelial transport permeability of oligopeptides across Caco-2 cell monolayers. Results showed that oligopeptides with different N-terminal amino acids had a wide range of permeability values and could be divided into three levels according to their correlations with log D and MW. At a good level of permeability, the permeability was positively correlated with log D, but negatively correlated with MW (p<.001); at an intermediate level of permeability, the permeability was negatively correlated with log D and MW (p<.001); and at a low level of permeability, the permeability was positively correlated with log D and MW (p<.01). These results suggest for the first time that the transport of oligopeptides across Caco-2 cell monolayers might be closely related to their molecular properties of log D and MW. PRACTICAL APPLICATIONS: A great number of food-derived bioactive peptides display health-promoting effects and show potential as bioactive ingredients in functional foods. However, the poor absorption in the intestine limits the application of food bioactive peptides, especially for the oligopeptides containing more than three amino acids. Although the transepithelial transport of food-derived oligopeptides in the intestinal epithelium has been widely reported, its transport mechanism is still obscure. Our study shows a three-level relationship between the transport permeability and log D and MW of oligopeptides across Caco-2 cell monolayers and provides a novel evidence for the coexistence of transcellular and paracellular pathways for the transport of oligopeptides through the intestine. This result will contribute to the understanding of the transport mechanisms of oligopeptides in the intestine.

Estimation of skin permeation by liquid chromatography

Dermal absorption is a key process in the drug delivery studies of the pharmaceutical and cosmetic industries, as well as in the fields of dermal toxicology, risk assessment, and the exposure of environmental pollutants. This process is typically described by the skin-water permeability coefficient. However, in vivo determination is laborious and expensive. Thus, in the last few years, the development of prediction models from structure descriptors or subrogation through physico-chemical measurements has gained interest. In the present work, a previous subrogation model based on the chromatographic retention on a common C18 column has been tested for a wide set of drugs with very different chemical nature and having a wide range of permeability values. A total of 65 compounds have been used to establish the correlation between skin permeation and the HPLC retention, corrected by the McGowan volume of the drug. Afterwards it was successfully validated in terms of robustness and prediction ability. Finally, the permeability coefficient was estimated for a set of 29 new drugs, and results compared to the ones obtained by other estimation methods, as well as the available in vitro measured values, with very good agreement.

Compiling and Mapping Global Permeability of the Unconsolidated and Consolidated Earth: GLobal HYdrogeology MaPS 2.0 (GLHYMPS 2.0)

AbstractThe spatial distribution of subsurface parameters such as permeability are increasingly relevant for regional to global climate, land surface, and hydrologic models that are integrating groundwater dynamics and interactions. Despite the large fraction of unconsolidated sediments on Earth's surface with a wide range of permeability values, current global, high‐resolution permeability maps distinguish solely fine‐grained and coarse‐grained unconsolidated sediments. Representative permeability values are derived for a wide variety of unconsolidated sediments and applied to a new global map of unconsolidated sediments to produce the first geologically constrained, two‐layer global map of shallower and deeper permeability. The new mean logarithmic permeability of the Earth's surface is −12.7 ± 1.7 m2 being 1 order of magnitude higher than that derived from previous maps, which is consistent with the dominance of the coarser sediments. The new data set will benefit a variety of scientific applications including the next generation of climate, land surface, and hydrology models at regional to global scales.

Empirical model to estimate permeability of surface sediments in the German Bight (North Sea)

As the determinant of solute and particle fluxes through sediments, quantifying sediment permeability is vital step in understanding of the exchange phenomena between the water column and sediment as permeability determines the mode and intensity of solute and particle fluxes. Reliable estimates of sediment permeability are therefore a constraint on the accurate implementation of benthic biogeochemical models. This is particularly true for the North Sea, as field data are scarce and available grain-size-based models fail to represent the full range of sediment types. In this study, we combine measurements of sediment permeability and grain size analysis with a generic permeability model to establish a high-resolution permeability map of the sediment in the German Bight (North Sea). Our results show a good agreement between model-based prediction and measurements of permeability, even for a wide range of permeability values.

Characterization of sorption behavior and mass transfer properties of four central africa tropical woods: Ayous, Sapele, Frake, Lotofa

This study provides the sorption isotherm, its hysteresis and their mass transfer properties of four Central Africa Tropical woods widely used for building construction: frake (Terminalia Superba), lotofa (Sterculia Rhinopetala), sapele (Entandrophragma Cylindricum) and ayous (Triplochiton Scleroxylon). Characterization of these four species in particular and Central Africa tropical woods in general were necessary to develop conservation and treatment of wood after first transformation using the drying. Also, moisture transport on wooden material used such as wall buildings can be facilitating to found the thermal comfort. Measurements of isotherms were performed using a dynamic vapor sorption apparatus (Surface Measurement Systems) at 20 and 40°C with air relative humidity ranged from 0% to 90%. Mass diffusivity was determined in steady state using a specific vaporimeter. Air permeability was determined using a specialized device developed to measure over a wide range of permeability values. Permeability and mass transfer properties were determined in the tangential direction with a ‘’false’’ quartersawn board (sapele and lotofa) and in the radial direction with a flatsawn board (ayous and frake). Samples of sapele, ayous and frake are heartwood when lotofa contains as well as heartwood than sapwood. Results obtained showed that the temperature effect on sorption behavior was quite low. We observed also a low difference between the sorption behavior of these different species and hysteresis of sorption decreases when temperature increases. Hailwood-Horrobin model’s explains plausibly the experimental sorption isotherms data. Results on characterization of mass transfer properties showed that, in the steady state, mass diffusivity decreases exponentially when basal density increases. Mass diffusivity was higher in desorption than in adsorption phase. The gaseous permeability of these species was between than those of Australian hardwoods and temperate woods. It was difficult to define a relationship between permeability and mass diffusivity.

A Simple Approximate Semi-analytical Solution for Estimating Leakage of Carbon Dioxide Through Faults

Abstract Assuring CO2 storage security is essential for the widespread implementation of carbon capture and sequestration. Appraising the potential for leakage through faults in seals is an important component of site screening, assessment, and selection. The focus of this study is to understand and quantify the potential rates of CO2 leakage via faults and fractures which could provide fluid migration pathways from the storage reservoir to overlying aquifers. Several analytical solutions exist for estimating rates of fluid migration between reservoirs via faults or leaky wells [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8] . However, there is little focus on leakage up finite length faults. Here we present a new semi-analytical approximate solution for CO2 leakage through a finite length fault zone that relies on a derivation similar to that of calculating the single phase flow rate through a series of units. Under many conditions, this solution provides a good first order estimation of the amount of CO2 that leaks into the overlying aquifer relative to the amount of CO2 injected into the system with only basic knowledge of system geometry and permeability values. Detailed sensitivity analysis of simulation models was performed in order to understand which fault and reservoir parameters most strongly influence leakage rates of CO2 from storage reservoirs. Based on this analysis the three most important parameters were, in order of sensitivity, reservoir permeability, fault permeability and aquifer permeability. With these results, a semi- analytical approximation was developed which relies almost entirely on these permeabilities and the geometry of the system (ie. reservoir and aquifer height, fault thickness, etc.) While this solution does not incorporate multiphase fluid flow properties, it still provides a good approximation for CO2 leakage from a saline aquifer especially when the relative permeability characteristic curves result in mobility ratios near one for typical CO2 saturation values in the plume, which is common for Brooks-Corey relative permeability curves and viscosity ratios for supercritical CO2 and brine at reservoir conditions. Results from this semi- analytical solution are compared to over 50 different numerical models with different fault geometries and locations and a wide range of permeability values for the reservoir, fault and overlying aquifer. Overall, leakage predictions from the analytical solution compare very well with the numerical simulations. The approximation improves when faults are assumed to have no capillary pressure however many cases with capillary pressure are examined. Finally, the approximation is more accurate at lower leakage rates (leakage

Drainage and Imbibition CO2/Brine Relative Permeability Curves at in Situ Conditions for Sandstone Formations in Western Canada

One of the most important mechanisms for CO2 storage in deep saline aquifers is CO2 trapping at irreducible saturation, which depends on the relative permeability characteristics of CO2/brine systems. CO2 injectivity, pressure build-up and the evolution and long-term fate of the injected CO2 also depend on the same relative permeability characteristics. Predicting the fate of the injected CO2 using numerical models requires adequate relative permeability relationships for CO2/brine systems (both drainage and imb ibition cycles), yet very few experimental data exist in the literature. Considering that CCS will be deployed on a large scale in western Canada, three experimental programs of determining the relative permeability characteristics at in-situ conditions of prospective storage aquifers have been successively run between 2003 and 2011. The first two programs focused on testing rocks from various deep carbonate and sandstone aquifers in central Alberta in the vicinity of several very large CO2 sources. The third testing program focused on measuring the relative permeability for CO2/brine systems at various locations in the sandstone Basal Aquifer that overlies the Precambrian basement in western Canada. The results of the first testing program, comprising 14 measurements, have been published in 2008. The results for relative permeability testing on eight additional carbonate rocks have been published in 2010 and combined with the results for five tests from the first measurement program to obtain generalizations for carbonate rocks. Results of new CO2/brine relative permeability measurements on 16 sandstone rocks from the second and third measurement programs are presented for the first time in this paper. These results are combined with results of testing on six sandstone rocks from the first measurement program, for a total of 22 tests, and are generalized similarly to the generalization for carbonate rocks published previously. The test data cover a very wide range of permeability values, from less than 0.1mD to more than 500mD. The generalizations in terms of relative permeability and residual saturation are defined based on rock characteristics that are routinely measured in core analyses, such as pore size and absolute permeability.

Mass transfer properties (permeability and mass diffusivity) of four Australian hardwood species

Characterization of mass transfer properties was achieved in the longitudinal, radial, and tangential directions for four Australian hardwood species: spotted gum, blackbutt, jarrah, and messmate. Measurement of mass transfer properties for these species was necessary to complement current vacuum drying modeling research. Water-vapour diffusivity was determined in steady state using a specific vapometer. Permeability was determined using a specialized device developed to measure over a wide range of permeability values. Permeability values of some species and material directions were extremely low and undetectable by the mass flow meter device. Hence, a custom system based on volume evolution was conceived to determine very low, previously unpublished, wood permeability values. Mass diffusivity and permeability were lowest for spotted gum and highest for messmate. Except for messmate in the radial direction, the four species measured were less permeable in all directions than the lowest published figures, demonstrating the high impermeability of Australian hardwoods and partly accounting for their relatively slow drying rates. Permeability, water-vapour diffusivity, and associated anisotropic ratio data obtained for messmate were extreme or did not follow typical trends and is consequently the most difficult of the four woods to dry in terms of collapse and checking degradation.

Surface Resistivity Measurements Evaluated as Alternative to Rapid Chloride Permeability Test for Quality Assurance and Acceptance

ASTM C1202 tests were conducted at various ages with the corresponding surface resistivity test, and the results were compared. Samples tested included field- and laboratory-prepared samples. The laboratory test matrix tested several mixtures common to Louisiana at a wide range of ratios of water to cementitious materials (w/cm) to evaluate the range of the surface resistivity meter. The surface resistivity measurements correlated well with rapid chloride permeability measurements across a wide range of permeability values and sample testing ages. Suitable correlations were found between both the 14-day and the 28-day surface resistivity values and the 56-day rapid chloride permeability values. The variability of the surface resistivity test results is usually less than the variability of the rapid chloride permeability test results. The surface resistivity meter was also able to identify great differences in w/cm ratios for the same mixtures. The surface resistivity meter was determined to be user friendly. The preliminary cost–benefit analysis showed that implementation of the device would save the department about $101,000 in personnel costs in the first year. It is estimated that contractors would save about $1.5 million in quality control costs. The cost–benefit ratio for this project is estimated to be about 15. A Louisiana Department of Transportation and Development test requirements procedure, TR 233, has been developed and implementation of the surface resistivity device has begun.

Rotational and translational self-diffusion in concentrated suspensions of permeable particles

In our recent work on concentrated suspensions of uniformly porous colloidal spheres with excluded volume interactions, a variety of short-time dynamic properties were calculated, except for the rotational self-diffusion coefficient. This missing quantity is included in the present paper. Using a precise hydrodynamic force multipole simulation method, the rotational self-diffusion coefficient is evaluated for concentrated suspensions of permeable particles. Results are presented for particle volume fractions up to 45% and for a wide range of permeability values. From the simulation results and earlier results for the first-order virial coefficient, we find that the rotational self-diffusion coefficient of permeable spheres can be scaled to the corresponding coefficient of impermeable particles of the same size. We also show that a similar scaling applies to the translational self-diffusion coefficient considered earlier. From the scaling relations, accurate analytic approximations for the rotational and translational self-diffusion coefficients in concentrated systems are obtained, useful to the experimental analysis of permeable-particle diffusion. The simulation results for rotational diffusion of permeable particles are used to show that a generalized Stokes-Einstein-Debye relation between rotational self-diffusion coefficient and high-frequency viscosity is not satisfied.

DISTRIBUTION OF PETROPHYSICAL PARAMETERS IN THE CAMBRO‐ORDOVICIAN DIBSIYAH MEMBER OF THE WAJID SANDSTONE, SW SAUDI ARABIA

The Cambrian‐Ordovician Dibsiyah Member is the lowermost unit of the Wajid Sandstone, a major aquifer in SW Saudi Arabia. The Dibsiyah is present throughout most of south‐central Arabia including the Rub'Al‐Khali Basin where it is a potential exploration target and a reservoir for gas. The Member can be divided into Upper and Lower Units based on depositional facies. The Lower Unit is interpreted to have been deposited in a fluvial setting, whereas the Upper Unit, which displays abundant bioturbation, was deposited in shallow‐marine conditions.Patterns of porosity and permeability distribution in the Dibsiyah Member were analysed statistically. In general, the Member exhibits a limited range of porosity values and a wide range of permeability values. Histograms show that the porosity distribution of both Lower and Upper Units are approximately normal, and that their corresponding vertical and horizontal permeability distributions are positively skewed.The coefficient of variation for porosity in both the Lower and Upper Units is less than 0.5 indicating that the porosity range is small. However, the horizontal and vertical permeability values are more variable due to the spatial distribution of architectural elements and sedimentary structures within both units. The dissolution of unstable minerals, together with inhomogenous grain packing and poor connectivity, has resulted in a variable permeability distribution.

A permeability measurement system for tissue engineering scaffolds

A permeability measurement system is developed to quantify the inter-pore connectivity of tissue engineering scaffolds. It uses dry air as the fluid medium and allows rapid measurement operations. The paper analyses the fluid phenomena in porous structures, providing a theoretical background for the developed system. A nonlinear least-squares algorithm is developed to estimate the effective porosity, from which the intrinsic permeability is derived based on the mean pore size of the scaffold. It is shown that the flow in the measurement operations does not have to be within Darcy's region. The developed system can be used to characterize tissue engineering scaffolds with a wide range of permeability values.

Depositional controls on petrophysical properties and reservoir characteristics of Middle Miocene Miri Formation sandstones, Sarawak

Rock exposures around the town of Miri, Sarawak, belonging to the Miri Formation (Middle Miocene strata), represent the uplifted part of the subsurface sedimentary strata of the Miri oilfield. Data derived from outcrop studies concerning facies and sand body characteristics, and petrophysical properties are crucial for subsurface reservoir characterization and modeling of hydrocarbon reservoirs deposited in similar settings. The aim of this paper is to integrate lithofacies and petrophysical properties of Miri sandstones, in order to characterize and quantify the Miri reservoirs. The Miri Formation consists of a wide range of siliciclastic, tide-generated and storm-and wave- generated facies. Twelve lithofacies have been identified and grouped into two major facies associations: (i) the estuarine, tide-dominated, and (ii) the shoreface-offshore transition, storm-and wave-dorninated facies associations. The estuarine lithofacies are characterized by distinct and diagnostic tidal signatures; tidal dune cross-bedding with mud draped cosets and foresets including mud couplets, bidirectional (herringbone) cross-bedding, rhythmic stratifications, flaser bedding, wave bedding and lenticular bedding. Shoreface-offshore transition, storm-and-wave facies association is represented by sandstone bodies with evidences of storm and wave generated sedimentary structures; swaley cross-stratified sandstones, amalgamated hummocky cross-stratified sandstones, bioturbated sandstones and mudstone inter-bedding with parallel stratified to hummocky cross-stratified sandstone. Petrophysical properties were determined for six sandstone lithofacies: (i) Lithofacies A (multiple stacked trough cross-bedded sandstone, tidal channels and bars, estuary mouth), (ii) Lithofacies B (parallel-bedded sandstone of estuary upper flow sand flat), (iii) Lithofacies F (homogeneous coarse sandstone, outer estuarine tempestites), (iv) Lithofacies G (swaley cross­ stratified, upper-to-middle shoreface sandstone), (v) Lithofacies I (fine-grained bioturbated sandstone of the lower shoreface) and (vi) Lithofacies L (fine-grained, hummocky cross stratified sandstone, offshore transition). These lithofacies are characterized by a wide range of permeability values, which vary by several orders of magnitude (0.35 to 287 md), while porosity vary by only a few percent. Lithofacies A and F recorded the best reservoir properties; porosities are 23.3-29.7% and permeabilities are 9.64-287 md. Lithofacies G shows a wide range of porosity and permeability values that range from high to low reservoir properties; porosities are 23.5-27.5% and permeabilities are 3.4-45 md Lower shoreface and offshore transition (lithofacies I and L respectively) display the lowest reservoir properties; porosities are 13.5-24.5 % and permeabilities are 035-3.4 md In general, high reservoir quality of Miri sandstones is associated with coarser grain size, low clay contain and better sorted grains. Extensive clay drapes, bioturbation, and increasing proportion of very fine grains content result in significant decrease in permeability in both tide-generated and wave-generated lithofacies.

Permeation measurements in ethylene‐1‐hexene, ethylene‐1‐octene, and ethylene‐1‐dodecene copolymers synthesized with metallocene catalysts

AbstractThe permeation behavior of different ethylene‐1‐hexene, ethylene‐1‐octene, and ethylene‐1‐dodecene copolymers synthesized with metallocene catalysts has been analyzed. These copolymers cover a wide range of comonomer contents, so their crystallinities display rather considerable variations. The results for the permeability to oxygen of the different ethylene copolymers show that the main factor influencing the permeability is the noncrystalline fraction, although some influence of the kind of comonomer may also be present, which may be explained by the fact that when the alkyl branch of the α‐olefin is longer, there is an increase in the free volume in the amorphous and interfacial regions, causing slightly higher values of the permeability coefficient. From the results with different gases, it follows that, in general, an increase in the size of the penetrant (as expressed by its kinetic diameter or critical molar volume) leads to an increase in the solubility and a decrease in the diffusion coefficient. A wide range of permeability values is covered by these ethylene copolymers, depending basically on the crystallinity of the sample, but the permselectivity of CO2 with respect to oxygen (and probably between other pairs of gases) does not differ very much among the different copolymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2174–2184, 2003

Water-permeability measurement of high performance concrete using a high-pressure triaxial cell

Water permeability of concrete is used to indicate its durability. Accurate and reproducible measurement of water permeability is difficult and becomes more difficult as the quality of concrete increases. When high-performance concrete (HPC) is tested, these concerns become more pronounced. HPC is used widely to improve the durability and performance of structures but there are few test procedures able to evaluate its permeability-related properties. In this study the water permeabilities of concretes including HPC were measured using a highpressure triaxial cell with a sensitive and automated measurement capability. Special analysis procedures were developed to obtain useful data from the extremely low volume of water being measured. This method was able to measure a wide range of permeability values from 10 −12 m/s to 10 −16 m/s, with reproducible measurements on replicates.

Hydrodynamic interactions of two permeable particles moving slowly along their centerline

The hydrodynamic interaction between two permeable spherical particles moving with constant velocity along the line of their centers in a fluid at infinity at rest is analyzed. The motion of the fluid in the domain between and around the two spheres is described by Stokes' equation, whereas the motion of the fluid in the interior of the porous spheres is assumed to obey Darcy's law. At the porous boundaries, continuity of the pressure and normal fluid velocity is used complemented by the simplified Beavers-Joseph slip condition. Analytical solutions for the flow field in the exterior and for the pressure field in the interior of the spheres are obtained using the stream function formulation in bispherical coordinates. Quasistationary vortices are obtained when the two spheres approach each other or when a porous sphere moves towards a porous planar wall over a wide range of permeability values. The hydrodynamic forces exerted by the fluid on the two spheres are determined as functions of the permeabilities of the spheres, the separation distance, the sphere size ratio, and the velocity ratio. Finally, the distribution of the normal and shear stresses exerted by the fluid on the surfaces of two simultaneously moving porous spheres is calculated for various permeability values. The numerical results of this work along with the qualitative conclusions drawn from them are useful in the modeling of cluster—particle or cluster—cluster agglomeration, particle—cluster deposition in crossflow and dep filtration, hydrodynamic interaction of macromolecule coils with each other and container or pore walls, and other similar phenomena.