Permeability Reduction Research Articles

Numerical modeling of geological sequestration of brine wastewater due to coal mining in the Ordos Basin, China

The coal resources play an indispensable role in the development of heavy industry in China, and coal mining activity leads to brine wastewater drainage, causing major risks for the aquatic environmental system. Thus, the effective and economic treatment of coal mine wastewater is vital to mitigate the environmental burdens, and geological sequestration by deep-well injection is a promising treatment technique. This study elucidates the physical and geochemical processes of coal mine wastewater transport in deep reservoirs and proposes an optimized injection scheme to satisfy environmental and economic benefits simultaneously in the Ordos Basin, China. First, a variable density and variable parameter groundwater reactive transport model is constructed to simulate the long-term process of deep-well injection for coal mine wastewater treatment. Then, the environmental metrics, i.e., the percentage of permeability reduction, the total mass and spatial second moment of the wastewater plume, and the economic metric defined as achieving a higher concentration at a higher injection rate are proposed to evaluate the performance of the injection scheme. The simulation results show that the secondary mineral anhydrite dominates the reduction of reservoir permeability due to the precipitation reactions with SO42− in the brine wastewater, and the permeability in the reaction zone decreases by 0.66 % ~ 1.26 % after 10 years in the basic scenario. Moreover, higher concentrations negatively affect reservoir permeability and increase total dissolved solids, while higher injection rates decrease reservoir permeability and increase the brine wastewater plume. The study also identifies promising schemes that can achieve an optimal trade-off between the conflicting metrics. Based on the economic and environmental benefits demanded in this study, an injection scenario with a concentration of C4 and an injection volume of 800 m3/d is recommended to maximize environmental benefits. Overall, this numerical study offers significant implications for designing an economically and environmentally sustainable treatment injection scheme for coal mining wastewater drainage.

Effect of steel fiber on the permeability of freeze-thaw damaged concrete under splitting tensile and compressive loads

This study investigated the effect of steel fibers on the permeability and mechanical properties of freeze-thaw damaged concrete under splitting tensile and compressive loads. A specially designed permeability apparatus is used to investigate the continuous permeability performance of steel fiber reinforced concrete (SFRC) subjected to loads. Results demonstrated that for the concrete without load, the addition of steel fibers exhibits a negative effect on the impermeability performance of the concrete matrix without freeze-thaw damage. The initial permeability of SFRC specimens is between 81.7 % and 180 % higher than that of NC specimens. The addition of steel fibers shows a positive effect on the impermeability of concrete subjected to freeze-thaw cycles. The permeability of SFRC under loads can be categorized into two stages. In the first stage, the concrete matrix is the main water channel. The addition of steel fiber can effectively increase the maximum radial deformation of the first stage and maintain low permeability of concrete in a large radial deformation range. In the second stage, concrete cracks are the main water channels. Both the addition of steel fibers and freeze-thaw cycles can reduce the permeability of the concrete in the second stage. Furthermore, under compressive load, with the increasing of stress level, the permeability of SFRC exhibits a slowly decreasing trend, this is followed by a significant increasing trend. The addition of steel fibers can maintain low permeability performance in a large stress level range, and as the steel fiber content increases, the permeability at peak load gradually decreases. The strain–permeability curves of SFRC under splitting tensile and compressive loads subjected to freeze-thaw cycles are investigated. The permeability of SFRC gradually increases with the increasing of the number of freeze-thaw cycles when the compressive strain exceeds 0.002. However, the opposite trend is observed under splitting tensile load. Notably, the reduction in concrete permeability due to the steel fibers is more significant under splitting tensile load than that under compressive load. Future work might integrate this research with stress-strain constitutive equations and finite element analysis. This will offer a foundational framework for engineering applications aimed at enhancing the permeability of steel fiber concrete under freeze-thaw conditions.

Minimizing the particles settling of ilmenite weighted oil well cement using laponite

Cementing operations are fundamental undertakings during the drilling and completion of oil and gas wells, ensuring zonal isolation and structural stability within the wellbore. Ilmenite serves as a dominant weighting material for high-density cement. However, challenges associated with its particle settling have arisen, reporting the potential for various complications within the cement sheath. In this context, the present study used laponite, a synthetic layered clay, to address the issue of particles settling in ilmenite-weighted oil well cement under high pressure and high-temperature curing conditions. The investigation extended to comprehensively assessing the consequences of incorporating laponite on the cement's rheological, mechanical, and petrophysical properties. Varied concentrations of laponite were employed and compared against the base cement, devoid of laponite. A total of six high-density cement samples of 18 ppg at different concentrations of laponite were prepared under a high pressure of 3000 psi and a high temperature of 294 °F. Findings from this work revealed that an optimal laponite concentration of 0.3% by weight of cement (BWOC) appeared to be the most effective. Adding laponite to the cement led to an impressive 83% reduction in particle settling within ilmenite-weighted cement. This deduction was confirmed through the direct density variation method and NMR measurements. Moreover, the inclusion of laponite yielded favorable outcomes in the rheological aspects of oil well cement. Laponite-based cement showed a 40% reduction in plastic viscosity and a 31.5% and 14.5% increase in yield point and gel strength, respectively, compared to the base cement formulation. Mechanically, laponite had a tangible positive impact, evidenced by a 95% and 131% increase in compressive and tensile strengths, respectively and a 16% reduction in Young's modulus, all relative to the base cement sample. Significantly, laponite's role extended to pore space optimization, leading to a decline in cement porosity by 2% and a 25% reduction in permeability.

Role of nano‐zones in enhancing the performance of YSZ coatings under thermal shock conditions

AbstractThermal barrier coatings have been widely employed in high‐temperature turbine blades to enhance their resistance against corrosion, oxidation, and foreign object damage. Yttria‐stabilized zirconia (YSZ) coatings, both conventional and nano‐structured, exhibit distinct characteristics. Notably, nano‐structured coatings demonstrate remarkable reductions in oxygen permeability and thermally grown oxide (TGO) layer thickness owing to the presence of nano‐zones (NZs). This paper focuses on elucidating the formation mechanisms, dispersion patterns, and behavior of NZs under varying conditions. Furthermore, it investigates the shock resistance performance of YSZ coatings subjected to furnace heating and water quenching. The findings reveal that the incorporation of NZs effectively restricts oxygen penetration and TGO growth and significantly enhances the overall performance of the coatings.

Bioinformatics analysis of gene bhsA and its role in Ca2+ -treated Escherichia coli.

One of the commonly employed methods in molecular biology is to utilize calcium chloride to treat Escherichia coli for the preparation of competent cells to facilitate foreign gene expression. However, the molecular mechanisms underlying Ca2+ mediation of competent cell formation and identification of the key genes involved in the process remain unclear. In previous studies, the combined analysis of transcriptomics and proteomics revealed bhsA as one of the crucial genes. The gene ontology functional annotation of bhsA identified it as a member of the YhcN family encoding an outer membrane protein that confers resistance to various stresses. The IPR0108542 domain found within the protein plays a significant role in stress response and biofilm formation in E. coli. Analysis of the STRING database showed that the proteins interacting with bhsA are primarily involved in biofilm formation and stress resistance. Using the RED homologous recombination method, a bhsA deletion strain was constructed to verify its role in E. coli genetic transformation. Although the mutant strain showed no significant differences in morphology or growth trend when compared to the wild-type strain, its transformation efficiency decreased by 1.14- and 1.64-fold with plasmids pUC19 and pET-32a. Furthermore, the 1-N-phenylnaphthylamine assay indicated a 1.71-fold reduction in cell membrane permeability in the mutant strain.

Preparation and characterization of potato starch-based composite films reinforced by modified banana fibers and its application in packaging of grapes

The current study focuses on the preparation and characterization of potato starch-based biocomposite films by reinforcing them with banana fiber. The banana fibers were modified using ultrasonication and cellulase enzyme, individually and in combination. Both native and modified banana fibers underwent physical, morphological, FTIR, and crystallinity analyses. The resulting biocomposite films, created by incorporating native and treated banana fibers, were then evaluated for their mechanical, thermal, barrier, and biodegradable properties. The findings indicated that combining ultrasound with enzyme treatment of banana fibers in the potato starch matrix led to a substantial reduction in water-sorption and water-vapor permeability (0.156 g mm m−2 h−1 kPa−1) of the packaging films. Additionally, the mechanical properties (5.02 MPa-Tensile strength, 4.27 MPa-Sealability) of the films significantly improved with the inclusion of modified banana fibers. FTIR analysis revealed similar spectra for all modified samples, along with enhanced crystallinity. Moreover, the thermal stability of the developed films was enhanced by the incorporation of modified banana fibers. Scanning electron microscopy showed that the modified fibers exhibited smooth surfaces and an even distribution of spaces compared with the native fibers. The biocomposite films demonstrated biodegradation within 42 days. Furthermore, the packaging application was tested with grapes, which showed that the films could maintain storability for up to 8 days. Overall, these results suggest a promising eco-friendly method for producing packaging films with biocompatible, biodegradable, and non-toxic properties.

Feature Analysis on B–H Curves of Dust Cores Under the Application of DC Bias Field

To realize high efficiency power converters, it is very important to reduce loss of passive magnetic components of transformers and inductors in high frequency region. Iron loss behavior under a DC bias field is crucially important to characterize inductor performance, but it has not been well analyzed. In this study, the iron loss behavior of a Sendust dust core has been analyzed in relation to the change in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve shape using principal component analysis (PCA). The iron loss monotonically decreases with increasing the DC bias field accompanying the reduction of permeability and slight asymmetric change in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve shape. PCA can extract featured quantities of these change in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve shape. Consequently, it is revealed that the curvature of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</i> curve changes its polarity with increasing the DC bias field, and this behavior has a strong relationship with the reduction of iron loss.

Mineral Scaling Impact on Petrophysical Properties of Reservoir Rock in a Geothermal Field Located in Northwestern Iran

Summary As the usage of geothermal energy as a zero-emission power resource continues to grow in significance, comprehending the interplay between physical and chemical processes within geothermal reservoirs becomes crucial. In this study, a computationally efficient fluid flow and heat transfer model, combined with a fluid chemistry model, is used to simulate fluid circulation and mineral precipitation in reservoir rock, resulting in changes in rock porosity and permeability. A 2D hybrid approach is employed to solve transient mass and momentum conservation equations, coupled with an analytical solution of the energy equation proposed in the literature for geological formations. A marching algorithm is utilized to calculate velocity and temperature fields in the axial direction within the production zone. Mineral scaling is addressed using the outputs of the hybrid model to perform saturation index (SI) and solution/dissolution computations for qualitative and quantitative mineral precipitation modeling. Multiple criteria are considered to assess the likelihood and intensity of fouling issues. The analysis results are used in an empirical model to estimate rock secondary porosity and permeability changes over a 5-year period of heat extraction. The developed simulator is applied to model a site in the Sabalan geothermal field in Iran, and its initial verification is conducted using data from the same site in the literature. The findings in the study for a sensitivity on fluid circulation rate reveal that increasing water circulation flow rate increases precipitation rate and pumping power required. Furthermore, even minor instances of pore blockage can result in notable reductions in permeability. Consequently, ensuring precise control over pressure and temperature during the production phase becomes progressively crucial for both reservoir integrity and production assurance. The proposed framework provides a promising approach for accurate and efficient simulation of geothermal reservoirs to optimize power generation and minimize environmental impact.

Influence of particle size distribution on biocarbonation method produced microbial restoration mortar for conservation of sandstone cultural relics

Biocarbonation of reactive magnesia based on microbially induced carbonate precipitation (MICP) process is a sustainable geotechnical reinforcement technology for strength development and permeability reduction. This method can be used to produce microbial restoration mortar (MRM) for the application of stone cultural relics restoration. In this paper, the influence of particle size distribution on the strength and porosity of MRM was examined. By mixing fine and coarse sandstone powder in various proportions, nine different particle size distributions were obtained to investigate the restoration performance, including the unconfined compressive strength (UCS), porosity, and color difference. The results indicate that the well-graded particle size distribution can lead to the UCS improvement and porosity reduction of MRM. The findings also imply that adding fine sandstone powder to the coarse sandstone powder can provide extra bridging contacts within the soil matrix. These bridging contacts can be easily connected by the precipitated hydrated magnesium carbonates (HMCs) minerals, consequently resulting in more effective bonding and filling within the pore matrix. The microstructural images of MRM confirm the formation of HMCs, which exhibited a dense network structure, filling out the gap and bonding the sandstone powders. Furthermore, the microbial restoration mortar showed a high weather resistance to dry-wet cycles, acid rain, and salt attack, which is attributed to better stability and strength of HMCs than the original calcic cemented minerals in sandstone.

Digital core reconstruction based on discrete element and Markov chain-Monte Carlo methods

The digital core is an essential platform for pore-scale flow simulation in geoenergy exploitation, CO2 storage, and hydrogen storage. However, the existing reconstruction methods, such as the Markov chain-Monte Carlo (MCMC) method, can not obtain the digital core reflecting the influence of complex stress. Moreover, the discrete element method (DEM)-based reconstruction, which can consider the effect of stress, has yet to be reported to consider the actual particle shape. To this end, a hybrid reconstruction method based on DEM and MCMC methods is proposed in this study. Firstly, watershed and level set algorithms are used to segment and extract the contours of rock particles, and clump in PFC2D is used to fill the contours to establish a clump template library. Then, the initial condition (ground condition) digital core slice is established with clump packing based on porosity and particle size distribution. Subsequently, the stress loading simulation is carried out to obtain 2D digital core slices with different stress combinations. Finally, the MCMC method obtains 3D digital cores. This proposed method is used to reconstruct the digital core of Belgian fieldstone with different stresses and effective moduli, and the evolution of pore structure characteristics is analyzed. Results show that the stress compresses the range of the pore radius distribution curve, resulting in the shortening of the throat length distribution; the conductivity of the model is poor. The maximum reduction of porosity and permeability is 6.56% and 24.81%, respectively. The model with a large effective modulus has a stronger resistance to deformation and can protect the pore structure. These results prove that the method proposed can obtain the digital core reflecting the stress effects and provide a reference for accurately describing the in-situ rocks' pore structure and the pore-scale flow simulation.

Permeability impairment and oil recovery changes in porous media due to asphaltenes deposition during natural gas injection: An experimental study

Injection of natural/associated gas is widely used as an efficient method of enhanced oil recovery in carbonate oil reservoirs in both miscible and immiscible conditions. Due to reservoir oil compositional changes by injected gas, asphaltenes instability may occur. In spite of the broad reported studies on gas injection process, the effect of miscible gas injection phenomenon on asphaltenes precipitation and deposition at reservoir conditions has not been well attended. The aim of this study is to recognize the effect of miscible and immiscible injection of natural gas on the asphaltenes deposition, permeability alteration and oil recovery. Additionally, the impact of different live and recombined oil samples on asphaltenes instability is investigated. Permeability alteration by the formation of asphaltenes is analyzed through the permeability measurements before and after gas flooding. Permeability reduction is found to be function of miscibility state, injection pressure and type of oil samples. It is observed that experiments conducted with live oil and at lower injection pressures show more permeability reduction. It is assumed an additional oil recovery associated with fluid path diversion caused by asphaltenes deposition in miscible and immiscible conditions. The miscible gas flooding causes the lower asphaltenes deposition and lower recovery enhancement. These effects are due to the fluid path diversion, nevertheless, miscible natural gas injection has high potential of oil recovery. Due to miscible bank development, the composite core along with higher injection pressure respect to minimum miscibility pressure shows higher recovery in comparison to the short core sample.

Large-scale dispersion of the hierarchical (1D, 2D and 3D) carbonaceous nanofillers in thermoplastic polyurethane through supramolecular self-assembly and extrusion

ABSTRACT The hierarchical carbonaceous nanofillers viz. carboxylated multiwalled carbon nanotube (MWCNT-COOH as 1D), hydroxylated few-layer graphene (FLG-OH as 2D), and hybrid 3D i.e., MWCNT-COOH immobilized into FLG-OH were dispersed into segmented thermoplastic polyurethane (TPU) by twin-screw extrusion (TSE). The concentration of nanofillers was varied as 0.25, 0.5, 1.0, 2.0 and 5 wt%. To increase the level of dispersion, hybrid 3D nanofillers were also incorporated into TPU by producing cellular structures through supramolecular self-assembly route (SSAR). The cellular structure in which the nanofillers were found to be uniformly dispersed was then compounded by TSE technique. The large-scale uniform dispersion was observed at higher loading (2 wt%) by SSAR followed by TSE when compared with direct TSE. Uniform dispersion was found at 1 wt% loading by direct TSE. PU nanocomposite film reinforced with 2 wt% hybrid 3D nanofillers showed good gas barrier property with ~63% reduction of helium gas permeability to 472 cm3/m2/day from 1287 cm3/m2/day of neat PU film.

Experimental Study on the Dilatancy Characteristics and Permeability Evolution of Sandstone under Different Confining Pressures

It is of practical significance to investigate the dilatancy and seepage characteristics of tight sandstone gas under different confining pressures for its efficient development. Therefore, fluid–solid coupling triaxial loading experiments with gas-bearing sandstone were conducted. The results showed that the gas-bearing sandstone exhibited brittle characteristics with tensile–shear composite failure. The dual logarithmic model can better characterize the sandstone strength (R2 = 0.9952), whereas the fitting effect of the linear Mohr–Coulomb criterion is poor (R2 = 0.9294). The dilatancy capacity of sandstone was negatively correlated with confining pressure, and the dilatancy index decreased by 38.4% in the form of its convex power function with the increasing confining pressure. The sandstone underwent significant damage dilatancy during the yielding stage, resulting in a significant permeability recovery, with an increase of 67.0%~70.4%, which was greater than the decrease of 9.6%~12.6% in the elastic stage. In view of the different dominant factors of permeability reduction induced by pore compaction and recovery induced by crack development, the permeability model was established with volumetric strain and radial strain as independent variables, which could better reflect the whole process of permeability evolution.

Modeling study of the effects of intrinsic membrane parameters on dilutive external concentration polarization occurring during forward and pressure-retarded osmosis

In membrane-based desalination systems, the mass transfer coefficient is a critical determinant when estimating changes within the boundary layers. However, it is pivotal to recognize the substantial role of intrinsic membrane parameters that can significantly influence the formation of boundary layers by modulating the water and salt fluxes. In this context, we investigated the effects of intrinsic membrane parameters on dilutive external concentration polarization (dECP) during forward osmosis (FO) and pressure-retarded osmosis (PRO). In particular, the Péclet number is utilized to evaluate the degree of dECP. The results revealed that the effects of the membrane parameters on dECP differ completely in accordance with the membrane orientations or magnitude of hydraulic pressure. Moreover, this study emphasizes that the reduction of solute permeability, i.e., improving the selectivity, should be the priority of FO/PRO membrane optimization because solute permeability is the only parameter that simultaneously suppresses both the internal concentration polarization and dECP. Hence, the results of the current study are expected to serve as valuable guidelines for future FO/PRO membrane optimization research.

Physiological and transcriptomic insights into sugar stress resistance in osmophilic yeast Zygosaccharomyces rouxii

The osmophilic yeast Zygosaccharomyces rouxii has attracted increasing attention for its ability to survive and grow in extremely high sugar environments. This trait determines its role in fermentation process and results in contamination in the food industry. However, the behavior of Z. rouxii in regulating cell metabolism to combat high sugar stress and the corresponding mechanism have not been completely elucidated. Here, the resistance strategies of Z. rouxii against high glucose stress were explored by physiological analysis at cell membrane level and transcriptomic analysis. Physiological analysis showed that under high glucose stress, colony transparency increased, cell volume decreased, which was accompanied by reduction in permeability and integrity of cell membrane and subsequent gradual recovering. Additionally, the proportion of ergosterol and unsaturated fatty acids in cell membrane significantly increased under high glucose stress. A comparison of transcriptome data showed that most of the obtained differentially expressed genes (DEGs) involved in ergosterol and linoleic acid synthesis pathways as well as cell wall integrity (CWI) and high osmolarity glycerol mitogen-activated protein kinase (HOG-MAPK) pathways, which was in line with the results of physiological data. Our results provided a theoretic basis to develop the process control for the production of high sugar foods.

Synergistic effect of graphene oxide/zinc oxide nanocomposites on polylactic acid-based active packaging film: Properties, release kinetics and antimicrobial efficiency

Incorporating two different nanoparticles in nanocomposite films is promising as their synergistic effects could significantly enhance polymer performance. Our previous work conferred the remarkable antimicrobial (AM) properties of the polylactic acid (PLA)-based film using optimal formulations of synergistic graphene oxide (GO)/zinc oxide (ZnO) nanocomposites. This study further explores the release profile of GO/ZnO nanocomposite and their impact on the antimicrobial properties. A fixed 1.11 wt% GO and different ZnO concentrations were well dispersed in the PLA matrix. Increasing ZnO concentrations tended to increase agglomeration, as evident in rougher surfaces. Agglomeration inhibited water penetration, leading to a significant reduction in water permeability (46.3 %), moisture content (31.6 %) but an improvement in Young's Modulus (52.6 %). The overall and specific migration of GO/ZnO nanocomposites was found to be within acceptable limits. It is inferred that the release of Zn2+ ions followed pseudo-Fickian behavior with an initial burst effect. AM film with the highest concentration of ZnO (1.25 wt%) exhibited the highest inhibition rate against Escherichia coli (68.0 %), Bacillus cereus (66.5 %), Saccharomyces cerevisiae (70.9 %). Results suggest that GO/ZnO nanocomposites with optimal ZnO concentrations have the potential to serve as promising antimicrobial food packaging materials, offering enhanced barrier, antimicrobial properties and a controlled release system.

Analytical solution for chemical fluid injection into linear heterogeneous porous media based on the method of characteristics

Injection of Newtonian fluids in porous media to displace linearly another Newtonian fluid is described by the Buckley-Leverett (BL) fractional flow theory derived for incompressible, constant viscosity fluids at constant injection rate in a homogeneous and isotropic reservoir. Injection of non-Newtonian fluids can be addressed by modifying the fractional flow equation by considering the dependence of injected fluid viscosity with velocity, changes of residual oil saturation and chemical adsorption on rock. In this work, the BL fractional flow model is extended to describe injection of non-Newtonian fluids into a 1D linear heterogeneous formation accounting for fluid adsorption, permeability reduction, inaccessible pore volume, and presence of a denuded water bank developed over time ahead of non-Newtonian zone. Results from derived analytical solutions demonstrate fluids saturation and pressure drop across the formation, fluids production rate and cumulative volumes to be in close agreement with the ones from a commercial reservoir simulator.

Compositional Streamline-Based Modeling of Polymer Flooding Including Rheology, Retention, and Salinity Variation.

The chemical enhanced oil recovery (CEOR) technology that is most used worldwide is polymer flooding due to its proven commercial success at field scale, maturity, and versatility to combine with other technologies. So, there has been an increasing interest in expanding its applicability to more unfavorable mobility ratio conditions and adverse environments (such as high-temperature, high-salinity carbonate reservoirs, pH-sensitive polymers, and formations with active clays). Therefore, a requirement for successful field application is to find the design parameters of the process that balance material requirements and oil recovery benefits in a cost-effective manner, which is usually done through reservoir modeling. Polymer flooding predictive tools normally require detailed information and are based on time-consuming field reservoir simulations. Thus, for effective project management, a quick and sound tool is needed to screen for polymer flooding applications without giving up key physical-chemical phenomena that govern the oil recovery. In this research, we developed a two-dimensional polymer flooding model based on the streamlines approach. This is an alternative to having a multidimensional practical tool thoroughly representing the physical and chemical behavior of polymer flooding by considering key phenomena such as rheology behavior (shear thinning and shear thickening), salinity variations, permeability reduction, and polymer adsorption. Previously published streamline multidimensional models for polymer flooding lack the integrated modeling of the above-mentioned key phenomena. Additionally, the models to represent rheology and retention phenomena in the proposed tool consider a more complete description than the present streamline-based simulators. For the construction of streamlines, we considered a black oil formulation to estimate the pressure and saturation 2D distribution by applying the implicit in pressure and explicit in saturation method, coupled with an explicit formulation for the 2D composition computation. For saturation-composition along the streamlines, the 1D practical tool incorporated represents the polymer flooding key phenomena. The numerical algorithm used by the streamline-based tool is supported by laboratory experiments for waterflooding in homogenous porous media, analytical results for waterflooding in heterogeneous media, polymer flooding field scale simulation cases, and a CMG-STARS model built as a reference for waterflooding in both media (homogenous and heterogeneous) and for polymer flooding. The practical tool developed contributes to simplifying the upscaling from laboratory observations to field applications with better fitted numerical simulation models and to determining favorable scenarios; thus, it could assist in understanding how key parameters affect oil recovery without performing time-consuming CEOR simulations.

A novel supramolecular deep eutectic solvent enhancer for fracturing-oil expulsion fluids

Crude oil remains the predominant energy source today. Clean fracturing fluids (CFFs) have great potential to overcome the challenges of unconventional oil reservoir development due to their integrated fracturing-oil expulsion characteristics. The performance of CFFs is closely related to oil production. In this work, a novel β-cyclodextrin (β-CD)-based supramolecular deep eutectic solvent (SDES) was developed as a promising enhancer for CFF performance. The SDES facilitates the formation of high-strength micelle networks through hydrogen bonds and host–guest interactions to significantly improve the rheological properties, temperature resistance and drag reduction performances of CFFs. The ion–dipole interactions between SDES components and salt cations restrain micelle disassembly, thereby enabling remarkable resistance of CFFs to salt. SDES could further increase the imbibition efficiency to 45.4 % in 62 h because of its interface activity. SDES also endowed CFF with superior gel breaking performance and reusability. Moreover, SDES hardly resulted in the reduction of reservoir permeability. The β-CD in SDES further enhanced the interactions between compounds in CFFs, making it a more effective option compared with traditional DES. This work demonstrates the substantial potential of SDES as a new and green medium for improving the CFF performance, offering promising prospects for the industry.

Tough, flexible and oil-resistant film from sonicated guar gum and cellulose nanofibers for food packaging

Utilizing renewable and locally available raw materials in flexible film production with modifications and reinforcements is crucial in the fight against plastic pollution. This study investigates the use of sonicated guar gum for film production with reinforcement from cellulose nanofibers derived from sugarcane bagasse. Cellulose nanofibers were obtained with a yield of 46.6% and a purity of 95%, exhibiting a crystallinity of 75.64% and thermal stability up to 323 °C. Films were prepared using sonicated guar gum under varying process conditions (time: 0–12.5 min, amplitude: 50,100%), and the film with optimal properties was chosen for reinforcement with varying mass percentages of nanofibers. The film with 0.01 g of nanofiber reinforcement demonstrated significant improvements in tensile strength (23.04 MPa), elongation (39.19%), ultimate modulus (134.94 MPa), and a reduction in water vapor permeability (1.76 × 10−10 gm/m2Pas). This film also showed exceptional resistance to oil permeation, making it a promising candidate for packaging oil-based foods.