Filtration Channels Research Articles

Correlation between sewage sludge pore structure evolution and water filtration performance: Effect of thermal hydrolysis with or without carbonaceous skeleton-assisted

Municipal sewage sludge contains a high water content and strong hydrophilicity, making mechanical dewatering a critical step in sludge treatment and disposal. To clarify the collapse of filtration channels within the sludge cake under high pressure and to develop more precise targeted conditioning methods, this study focused on the direct correlation between pore structure evolution and sludge dewatering performance. A self-designed online system was used to compare the dewatering processes of raw sludge, thermal hydrolyzed (TH) sludge, and carbonaceous skeleton-assisted thermal hydrolyzed (CSkel-TH) sludge. In-depth analysis was conducted on the structure scanning data of the filter cake at different time intervals and the corresponding filtrate mass data. The results showed that during the press filtration process, the raw sludge gradually transformed into a filter cake, with larger pores trapping the water. In the upper and bottom layers, regions with a porosity higher than 10 % appeared, forming a “water-locking layer” even with continued pressure, it became impossible to remove additional water. After separate hydrolysis, the porosity and pore connectivity of the sludge decreased, and the thickness of the “water-locking layer” increased as press filtration progressed, inhibiting water discharge and making cake formation difficult. Following CSkel-TH treatment, the number of pores with diameters ranging from tens to over a hundred micrometers increased, and the connectivity between pores was enhanced. In this case, the channels formed by interconnected small pores continuously transported the water trapped in the large pores outward, facilitating water discharge. This work provided a basis for further targeted regulation of pore structures to enhance the effectiveness of high-pressure dewatering of sludge.

Automated image processing algorithm for 3D OCT images of fouling in spacer-filled membrane filtration channels

OCT imaging is an important technique to study fouling in spacer-filled channels of reverse osmosis systems for seawater desalination. However, OCT imaging of membrane filtration channels with feed spacers is challenging because the spacer material can be (partly) transparent, making it difficult to detect and possibly mistaken for fouling, and the longer optical pathway through the spacer material distorts the image below the spacer. This study presents an automated 3D OCT image processing method in MATLAB for visualization and quantification of biofouling in spacer-filled channels. First, a spacer template of arbitrary size and rotation was generated from a CT scan of the feed spacer. Second, background noise and file size were reduced by representing the OCT image with a list of discrete reflectors. Finally, the spacer template was overlayed with the feed spacer in the 3D OCT image, enabling automated visualization of the feed spacer and correction of the distortions. Moreover, the method allows the selection of datasets with the same location relative to the position of the spacer, enabling systematic comparison between datasets and quantitative analysis.•A spacer template of arbitrary size and rotation was generated from a CT scan.•The background noise was removed, and the file size was reduced by representing the OCT dataset with a list of discrete reflectors.•The spacer template was overlayed with the feed spacer in the 3D OCT image.

A synergistic polyelectrolytes-Zr-MOF hydrated construction graphene oxide nanofiltration with enhanced dye wastewater remediation

In recent years, developing an efficient nanofiltration membrane had been a thorny challenge for dye/salt wastewater purification. In this study, a novel graphene oxide-based nanofiltration membrane (GO/UiO@S-GO-8) was constructed by intercalating the synergistic polyelectrolytes-Zr-MOF hydrated construction (UiO@S-GO) into GO nanosheets. Here, combining the hydrophilic high-density anionic sulfonic groups (SO3-) with cationic amino groups (-NH2), GO-based nanofiltration membrane demonstrated outstanding separation ability, anti-pollution performance and structure stability. Compared to pure GO membrane, benefiting by effective expansion of graphene layer spacing from intercalation effect of UiO@S-GO, the water permeance of GO/UiO@S-GO-8 membrane increased to 8 times (about 66.3 ± 1.5 L m−2 h−1 bar−1). Importantly, the permeances of various dyes wastewater also reached up to 65.1 ± 1.8 L m−2 h−1 bar−1 at the high removal rate (exceeding 99.4%). Furthermore, strong hydratability of polyelectrolytes and hard porous crystal constructed the robust anti-fouling micro/nano rough structures onto the membrane surface, which made flux recovery rate (FRR) of GO/UiO@S-GO-8 enhanced to 96.7 ± 1.3%. Remarkably, the salt-resistant behavior of the polyelectrolytes and porous MOF could maintain the stability of the membrane filtration channels, the GO/UiO@S-GO-8 membrane could realize efficient removal rate of dyes (over 98%) faced the complex dye wastewater with different salt concentrations. Meanwhile, the GO/UiO@S-GO-8 membrane also could maintain the high permeance (46.7 ± 1.5 L m−2 h−1 bar−1) as well as excellent removal rate (97.2 ± 1.4%) after 10 cycle experiments. Hence, the GO/UiO@S-GO-8 nanofiltration membrane with Polyelectrolytes-Zr-MOF hydrated construction possessed a broad application inspiration in the purification of high-salt/dye wastewater.

GEOCRYOLOGICAL CONDITIONS OF THE FORMATION OF GIANT SPRING AUFEIS AT THE ANMANGYNDA RIVER (MAGADAN REGION) ACCORDING TO GEOPHYSICAL DATA

Giant aufeis fields, common in the Northeast of Russia, are the indicators of water exchange processes in cryosphere. The development of ideas about icing processes is relevant both from the fundamental point of view of studying the permafrost evolution, and from the practical point of view – for the development of aufeis hazard measures. The aufeis in the Anmangynda River basin (aufeis glade area 7 km2) is considered representative of the region, and its studies have been carried out since 1962. In 2022, during the period of maximum thawing of the active layer Electrical Resistivity Tomography (ERT) soundings were carried out at the aufeis glade aiming to identify underchannel taliks and flooded fault zones in bedrock, including local areas of groundwater discharge. It was found that within the main river channels there are underchannel taliks up to 30 m deep. According to the results of 2D inversion, local anomalies of low electrical resistivity mark groundwater filtration channels. In 3D geoelectrical models, pipe-like anomalies of low resistivity are identified in the areas of groundwater discharge, interpreted as filtration channels in the alluvium and the zone of exogenous fracturing in bedrock formed by sandy-clay shales, as well as linear vertical anomalies of low resistivity, interpreted as faults. On vertical sections of 3D resistive models, a connection between faults and filtration channels in alluvium and a layer of exogenous fracturing is traced. In the right bank of the valley, geoelectric signs of taliks in the bedrock, presumably associated with fault tectonics, have been established. It is assumed that the identified faults are the additional transit routes for groundwater in the Anmangynda River valley, along with the alluvial aquifer and the zone of exogenous fracturing of bedrock.

Assisting role of carbonaceous skeleton in sludge thermal hydrolysis and press filtration

As a key step in disposal and reutilization, sludge dewatering is very difficult, since extracellular polymers substances (EPS) binds the water, and compressible organic matter deforms and causes water filtration channels to collapse. Sludge dewaterability was demonstrated to enhance by carbonaceous skeleton (CSkel)-assisted thermal hydrolysis in our previously study. This work further investigated the assisting role of different types of CSkel in EPS decomposition during sludge thermal hydrolysis stage and channels reformation during press filtration stage. Two major types of CSkel, lignocellulosic waste (waste sawdust, waste straw, processing by-product) and protein-rich waste (shrimp shells, jatropha oil cake), were selected. The experimental results showed that in the thermal hydrolysis stage, the decomposition of lignocellulosic waste would increase fatty acids production by 28%, resulting in an acidic environment that reduced the total amount of three hydrophilic amino acids, i.e., glycine, serine and threonine. These promoted the release of water from the sludge. In the press filtration stage, average pore size of sludge was reduced by approximately 87% and nanoscale holes began to appear and increase. Assisting of CSkel rebuilt the filtration channels which brought good connectivity between the pores in sludge cake. Lignocellulosic waste proved significantly more effective than protein-rich waste in achieving a water removal rate of 88.63% under 1 MPa. This study provided a basis for selecting suitable CSkel to optimize sludge dewatering for subsequent utilization.

A clear view of biofouling in spacer filled membrane filtration channels: Integrating OCT and CT for improved visualization and localization

Spiral wound membrane elements for reverse osmosis (RO) seawater desalination are increasingly important to produce clean water to cope with the rising global freshwater scarcity. Spiral wound elements are prone to biofouling development which can be monitored in-situ using optical coherence tomography (OCT). Although OCT has emerged as a dominant technology for nondestructive monitoring of membrane fouling, the application of OCT to study fouling on feed spacers has been limited because image processing of spacers is complex. In this study, an automated image processing algorithm was developed for visualization and quantification of fouling in spacer filled channels. The spacer shadow was used to estimate the location of the spacer in the OCT image. Subsequently, a computed tomography (CT) scan of the same spacer type was overlaid, providing a clear indicator of the spacer position. The spacer position was used to i) correct the distortion below the spacer, ii) visualize fouling in 3D with reference to the membrane and spacer, and iii) reproducibly and precisely locate images to make time series and compare parallel experiments. The results showed that the addition of a spacer geometry as a solid object in a 3D representation of an OCT-scan greatly improves visualization, because fouling and the spacer can be distinguished and the position of fouling relative to the spacer and membrane can be clearly seen. Moreover, the ability to select a dataset relative to the orientation of the spacer will enable objective and automated quantitative analysis in future work.

Influence of the structure of the pore space of rocks on the wettability and adsorbed fluids of reservoir rocks

Theoretical and experimental studies of the effect of the geometry of the pore space on the wettability of collectors have been carried out. The special structure of the pore space of the Talinskaya area of the Krasnoleninsky deposit, due to the heterogeneity of the composition of rocks, leads to heterogeneity in the size and geometry of filtration channels and affects wettability. The specificity of the adsorption of polar components of oil causes changes in wettability and affects the amount of adsorbed oil. Keywords: pore space geometry; adsorbed fluids; wettability.

Study of structural characteristics of hydrocarbon reservoir pore space based on X-ray computed tomography images

Digital studies of pore space and internal structure of hydrocarbon reservoir were conducted on the basis of multiscale X-ray computed tomography images and the analysis of heterogeneities, cavernosity, fracturing and bedding in the rock. Main results. 3D models of rock pore space were created on the basis of computed tomography images through segmentation. Porosity estimation based on the digital approach was performed. It was shown that the digitally obtained data are in good agreement with the results of laboratory measurements. Analysis and visualization of the structure of the main filtration channels in the rock were performed. Pore size distributions in the specimen were obtained, and 3D visualization of the largest pore size was shown. Conclusions. The pore space characteristics obtained on the basis of tomographic approach are valuable data for filling reservoir models and can be used in solving the problems of permeability reduction during different kinds of reservoir impacts. Application of the obtained results in combination with geomechanical tests of rocks is intended to expand existing approaches to complex analysis of core material of reservoirs, as well as to supplement and refine mathematical and operational models of the studied objects.

METHODOLOGICAL ASPECTS OF THE STUDY OF THE RATE CONSTANT OF THE REACTION OF HYDROCHLORIC ACID WITH CARBONATE FORMATION ROCK

Hydrochloric acid treatments are most widely used to intensify oil production from carbonate reservoirs. But despite a wealth of experience in the use of hydrochloric acid treatments, the results of treatments often do not reach the planned values of oil production growth. Efficiency of acid exposure depends on the depth of penetration of the hydrochloric acid solution into the thickness of the productive reservoir, which, in turn, is conditioned by the degree of reactive activity of the acid composition. It is important to achieve the creation of filtration channels in the zone remote from the borehole, which will lead to an improvement in the filtration characteristics of the bottomhole formation zone to the proper extent. Therefore, in order to achieve the best result when planning acid exposure, it is important to consider the geological and physical properties of the object to be treated and select the appropriate formulation of the acid composition.
 The reaction rate constant is a parameter that allows you to take into account the compatibility of the acid composition and the geological and physical conditions of the productive reservoir. This parameter characterizes the rate of reaction between substances. However, a generally accepted method for studying the kinetic parameters of the reaction of acid compositions with carbonate formation rock has not yet been developed, which leads to low reproducibility of experimental results. The purpose of the research presented in the article is to develop a methodology for studying the kinetics of the reaction of hydrochloric acid with carbonate rock and to create a unified approach to determining the reaction rate constant, characterized by the greatest reproducibility of the results. The experimental part of the work was carried out in several stages, including the preparation of core material, the preparation of hydrochloric acid solution and its thermostating, and the further conducting of four series of studies at the PIK-OSG volumetric setup to determine the optimal acid-rock ratio, identify the optimal weight of the core material and establish the optimal coarseness of its grinding.
 The obtained results of experiments on the study of methodological aspects of the study of the rate constant of the reaction of hydrochloric acid with carbonate rock showed that the experiments should be conducted in conditions of an excess of rock relative to acid, in this case the mass of the core sample and the coarseness of the grinding of the core material will not affect the error in determining the reaction rate constant.

Effects of atorvastatin on the function of Tenon's capsule fibroblasts in human eyes.

This study aimed to explore the role of atorvastatin (ATO) in the prevention and treatment of the scarring of filtration channels after glaucoma surgery. Human Tenon's capsule fibroblasts (HTFs) were co-cultured with various concentrations of ATO. First, Cell Counting Kit-8 assay was performed to evaluate the effects of various concentrations of ATO on the viability of HTFs. Then, after the ATO stimulated the HTFs for 24h, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed to evaluate the apoptosis of HTFs. Transwell assay was also performed to evaluate the migration of HTFs. Moreover, enzyme-linked immunosorbent assay (ELISA) was performed to detect the protein expression levels of transforming growth factor-β1 (TGF-β1) and TGF-β2 in the cell culture supernatant of HTFs. Western blot was carried out to detect the protein expression levels of smooth muscle actin (SMA), p38, Smad3, fibronectin, collagen I and collagen III in different groups. The results revealed that ATO could inhibit the proliferation and migration of HTFs. Based on the TUNEL assay, 100μM and 150μM ATO could induce cell apoptosis. The ELISA results indicated that ATO could down-regulate the expression level of TGF-β2, and western blot analysis revealed that the protein expression levels of SMA, p38, Smad3, fibronectin, collagen I and collagen III in the TGF-β2 group were all up-regulated compared with the control group, whereas the addition of ATO could reverse this up-regulation. ATO could inhibit the proliferation and migration of HTFs and induce their apoptosis. It was preliminary proven that ATO could inhibit the signaling pathway induced by TGF-β. It is suggested that ATO could be a basis for the treatment of the scarring of filtration channels after glaucoma surgery.

Изучение изменений структуры пустотности горных пород при создании напряженного состояния методами электронной микроскопии

On the example of an oil deposit of the Vereisk age which is one of the deposits in the Volga-Urals, lithotypes of rocks are distinguished, characterized by a fundamentally different structure of the void space. For selected lithotypes experiments were carried out on core samples with a change in the stress state of rocks under conditions of volumetric (pseudo-triaxial) compression. The pressure created in the experiments is identified with the development of processes at a distance from the epicenter of the hydraulic fractures appearance. Core samples were studied before and after exposure by non-destructive testing methods. The study of the sample structures by standard and tomographic methods did not allow us to establish significant changes during loading of the samples. At the same time, some increase in rock permeability was established in experiments. With this in mind, the samples were studied according to a technique specially developed by the authors using electron microscopy. The use of microscopic studies made it possible to obtain quantitative information about the change in the void space at a level inaccessible to X-ray tomography. As a result, it was found that both for potential reservoirs and for impermeable rocks, there is an increase in the length and opening of pre-existing fractures, which can be considered as the formation of additional effective fluid filtration channels. The experiments performed have changed the idea of ​​the process of hydraulic fracture development and can be used in geological and technological calculations.

Filtration Performance of 3D-Printed Ceramic Pellets: Investigation Using CFD and Computed Tomography

This study demonstrates the potential for computer-aided engineering and additive manufacturing techniques to fabricate protective layer materials with a novel design of filtration channels. Using computational fluid dynamics (CFD) simulation for channels of various geometries, potential locations of the capture of solid dust particles in ceramic filter pellets were identified. The filter pellets were fabricated from ceramic material using laser stereolithography. The printed samples were subjected to a filtration test. The CFD simulation of the pellet channels to identify potential filtration locations, followed by a comparative assessment of the simulation results and the post-test X-ray computed tomography (CT) scan of the 3D-printed pellets, demonstrated the feasibility of CFD models for the design of filter materials. The study findings are intended for the development of innovative protective materials with filtering capabilities to be implemented in specific industrial refining applications

Improved quantitative evaluation of the fouling potential in spacer-filled membrane filtration channels through a biofouling index based on the relative pressure drop

In this study, a biofouling index based on the relative pressure drop is presented to quantitatively evaluate the amount of fouling in spacer-filled membrane filtration channels. The biofouling index was defined as the inverse of the time to reach a relative pressure drop of 100% and can be interpreted as a fouling rate or cleaning frequency. The index was applied to evaluate biofilm growth in membrane fouling simulators with reverse osmosis membranes and commercial feed spacers operated with different feed water nutrient concentrations and crossflow velocities. Biofilm accumulation on the membrane and feed spacer was characterized in situ using optical coherence tomography. We showed that the biofouling index is directly related to the volume of biofouling independent of the applied crossflow velocity and a suitable tool for improved quantitative comparison of the biofouling rate. Furthermore our results suggest that the pressure drop is better described as function of the velocity at the perimeter of a spacer cell instead of the average velocity in the channel. Although the biofouling index is developed for biofouling, the index may be applied to quantitatively assess mitigation strategies in spacer filled channels for a wider range of fouling types.

O wpływie zjawiska kolmatacji na wydajność odwiertu

"During the opening of a productive formation by drilling, penetration of clay particles from the drilling fluid into the leading filtration channels of the rock occurs. As a rule, productive formations are opened at pressures that are significantly higher than the formation pressure. The amount of hydrostatic repression depends on the density of the drilling fluid, the height of the liquid column, and the reservoir pressure. A classic example of the latter is the problem of studying changes in reservoir properties that occur at the drilling stage, where relatively small particles of drilling fluid penetrate along with the flow into the pore space. A decrease in the bottomhole zone permeability in oil wells leads to a significant decrease in oil production rates, and sometimes to their complete stop, which ultimately significantly affects the total oil recovery and economic indicators of the oil fields’ development. The decrease in permeability can be caused by many factors: – clogging of the bottomhole zone of the productive formation in the process of drilling a well; – formation of a crust in perforated channels during cumulative perforation; – colmatation of the bottomhole zone of the productive formation during the operation of the well; – clogging of perforated channels during well killing and subsequent clogging; – formation of deposits of paraffins and asphaltenes in the pores of the rock of the bottomhole zone of the well. Bottomhole zone damage (clogging) significantly affects the productivity of wells, and the permeability of the formation, determined by the results of hydrodynamic studies. At the same time, clogging is understood as damage of the bottomhole zone with drilling fluid when opening the productive formation, and deterioration of the properties of the bottomhole zone during cementing, perforation of the productive interval, swelling of clays, etc. This paper presents an analysis of laboratory and field studies of the influence of clogging on the productivity of wells when opening layers with different capacitive and filtration properties, and also provides an analytical estimation of this effect, both for vertical and horizontal wells."

Size-Based Sorting and In Situ Clonal Expansion of Single Cells Using Microfluidics

Separation and clonal culture and growth kinetics analysis of target cells in a mixed population is critical for pathological research, disease diagnosis, and cell therapy. However, long-term culture with time-lapse imaging of the isolated cells for clonal analysis is still challenging. This paper reports a microfluidic device with four-level filtration channels and a pneumatic microvalve for size sorting and in situ clonal culture of single cells. The valve was on top of the filtration channels and used to direct fluid flow by membrane deformation during separation and long-term culture to avoid shear-induced cell deformation. Numerical simulations were performed to evaluate the influence of device parameters affecting the pressure drop across the filtration channels. Then, a droplet model was employed to evaluate the impact of cell viscosity, cell size, and channel width on the pressure drop inducing cell deformation. Experiments showed that filtration channels with a width of 7, 10, 13, or 17 μm successfully sorted K562 cells into four different size ranges at low driving pressure. The maximum efficiency of separating K562 cells from media and whole blood was 98.6% and 89.7%, respectively. Finally, the trapped single cells were cultured in situ for 4-7 days with time-lapse imaging to obtain the lineage trees and growth curves. Then, the time to the first division, variation of cell size before and after division, and cell fusion were investigated. This proved that cells at the G1 and G2 phases were of significantly distinct sizes. The microfluidic device for size sorting and clonal expansion will be of tremendous application potential in single-cell studies.

Geoenvironmental aspects of mine methane emissions


 
 
 The purpose of the work is to reveal the regularities of the influence of the gaseous phase on the process of filtering carbonated liquid and to characterize the physi-cochemical processes during the implementation of the method of reducing mine methane emissions. The development of minerals can be accompanied by the release of a large amount of methane into the mined-out space. This leads to atmospheric air pollution and consequently to ecological disturbances. This causes methane emissions to the mined-out space and to the surface of the earth cause by the filtration processes of gases and liquids in the rocks. The intensity of fluid filtration through crack and pore systems depends on the content and properties of the fluids and the reservoir properties of the rocks. It is known that methane release to the atmosphere can be observed after mines have been mothballed. This is a problem for many countries around the world where coal and oil and gas fields are being exploited. Investment in methane production and utilization projects is therefore important. Research on fluids filtration processes allow for the development of effective methane recovery methods, and ways to reduce methane emission speed. The result is the reduced air pollution and an improved environmental situation. The paper presents the filtration properties of rocks with different structures and textures. Filtration of carbonated liquid (water-methane) in fractures and pores is considered. It found that an increase in methane concentration in the carbonated liquid leads to a decrease in the phase permeability coefficient for water and an increase for methane. This character of change in phase permeability leads to methane accumulation in crack and pores. The dependence of the average carbonated liquid filtration rate in a rectilinear fracture on the methane concentration and the fracture axis angle of inclination is obtained. The average ascending filtration speed of the carbonated liquid is determined to be greater than the average descending filtration speed. This is due to the effect of the ejection force that acts on the gas bubbles in the liquid. The authors propose a method of blocking methane seepage by physicochemical treatment of the rock mass. The methane blocking effect is achieved by creating a gas-tight zone in areas with a high risk of methane migration to the ground surface. The result is a reduction in methane emissions to the mined-out space and the environment. When the method is realized, the solid product of the polymer solution enters cracks with a disclosure greater than 6 μm or pore channels with an average diameter of 6 μm. At the same time, the water released by the destabi- lization of the polymer solution blocks the methane in small cracks and pores. In pore channels with an average diameter of less than 25 μm, there is a sharp increase in the dynamic viscosity of the polymer solution. This effect is due to an increase in the intermolecular interaction forces between the polymer solution and the walls of the filtration channels. Coagulation and destabilization of the polymer solution in cracks and pores is due to the separation of large agglomerates of macromolecules.
 
 

A deep neural networks framework for in-situ biofilm thickness detection and hydrodynamics tracing for filtration systems

The growth of biofilm inside the filtration channels module is hard to visualize and has a high propensity to tarnish the process performance. Herein, Deep Neural Networks (DNN) are utilized to gauge biofilm thickness and connect its growth with hydrodynamics parameters to establish a control strategy in an artificially intelligent framework. A database of biofilm images is created from the Optical Coherence Tomography (OCT) scans of various ultrafiltration and membrane distillation experiments.A Convolution Neural Network (CNN) is trained to determine the biofilm thickness from the OCT scans. The trained CNN network can instantly predict 2D and 3D biofilm thickness for unseen OCT images of different filtration technologies (ultrafiltration or membrane distillation) with reasonably accurate prediction performance compared to manual calculations. A mean squared error of less than 0.008 µm2 is achieved for a set of 300 testing images while determining the biofilm thickness. Further, a synthetic database is created using a theoretical model to associate the cylindrical channel pressure drop (100–1500 mbar/m) with channel thickness (up to 787 μm) that hypothetically relates growing biofilm with the channel hydrodynamics and geometric parameters (velocity 0.1–0.16 m/s, channel radius 10–21 cm, viscosity 0.0007–0.003 Ns/m2). A Non-Linear Regression-DNN (NLR-DNN) is trained and predicts output quantities (either channel pressure drop or biofilm thickness) below 2 % absolute error against the analytical solution. The validating dataset is compared directly with the theoretical model, and a good fit of R2 = 0.9999 was achieved. The developed framework can potentially be deployed in desalination plants for early decision-making and preventive controls.

Microfluidic Sliding Paper-Based Device for Point-of-Care Determination of Albumin-to-Creatine Ratio in Human Urine.

A novel assay platform consisting of a microfluidic sliding double-track paper-based chip and a hand-held Raspberry Pi detection system is proposed for determining the albumin-to-creatine ratio (ACR) in human urine. It is a clinically important parameter and can be used for the early detection of related diseases, such as renal insufficiency. In the proposed method, the sliding layer of the microchip is applied and the sample diffuses through two parallel filtration channels to the reaction/detection areas of the microchip to complete the detection reaction, which is a simple method well suited for self-diagnosis of ACR index in human urine. The RGB (red, green, and blue) value intensity signals of the reaction complexes in these two reaction zones are analyzed by a Raspberry Pi computer to derive the ACR value (ALB and CRE concentrations). It is shown that the G + B value intensity signal is linearly related to the ALB and CRE concentrations with the correlation coefficients of R2 = 0.9919 and R2 = 0.9923, respectively. It is additionally shown that the ALB and CRE concentration results determined using the proposed method for 23 urine samples were collected from real suffering chronic kidney disease (CKD) patients are in fine agreement with those acquired operating a traditional high-reliability macroscale method. Overall, for point-of-care (POC) CKD diagnosis and monitoring in clinical applications, the results prove that the proposed method offers a convenient, real time, reliable, and low-spending solution for POC CKD diagnosis.

Influence of the filtration channels area on well productivity during the secondary opening of the productive horizon in the carbonate sequence

Influence of the filtration channels area on well productivity during the secondary opening of the productive horizon in the carbonate sequence

FACTORS AFFECTING THE GAS RECOVERY COEFFICIENT AT GAS CONDENSATE FIELDS WITH ABNORMALLY HIGH RESERVOIR PRESSURE

The results of numerical experiments to assess the influence of abnormally high reservoir pressure on the dynamics of pressure reduction at the bottom and the supply circuit, flow rate and life of wells are presented. It is shown that the growth of the anomaly coefficient of reservoir pressure has a positive effect on the dynamics of the considered indicators. It has been established that in hydrocarbon deposits with abnormally high reservoir pressures, the rock pressure of up to 75% is balanced by the pressure of saturating hydrocarbons. High rates of gas extraction, achieved due to large depressions on the reservoir in producing wells, lead to reservoir deformation, which in fractured and fractured-pore reservoirs leads to the closure of hydrocarbon filtration channels. Using the example of the Severny Nishan gas condensate field, it is shown that the deformation of the reservoir is the main reason for the low efficiency of development and the abandonment of half of the gas reserves in the reservoir. Hydraulic fracturing technology is recommended for the extraction of residual gas reserves. With an increase in the depth of the productive horizons, the proportion of hydrocarbon deposits with abnormally high reservoir pressures is steadily increasing. As it is known, the energy potential of productive layers is largely determined by the activity of the legal aquifer area. There are elision and infiltration natural water pressure systems. The experience of developing hydrocarbon deposits with AVPD shows that this factor, depending on the geological and physical conditions of the deposits, can affect the oil and gas recovery coefficient as a positive (increasing) and negative (decreasing) factor. At the same time, as positive factors, there is a higher concentration of reserves in the specific volume of the deposit, relatively high well flow rates, ensuring the gushing of wells for a long time, maintaining high reservoir properties of reservoir rocks, and as a negative factor, a decrease in stability and susceptibility of oil and gas saturated reservoirs to deformation processes.