Flow Filtration Research Articles

Improved infiltration rate determination method for interlocking-block permeable pavements using standard ASTM test apparatus

ABSTRACT Current standard methods of measuring permeability of interlocking-block permeable pavements (IBPPs) do not correctly measure the actual infiltration rates of IBPPs. The test results vary with test area size and location. In this study, employing the standard ASTM-1781 test apparatus, an improved procedure that adopts an experiment-based numerical approach is developed to overcome the problem. It involves the following steps: (i) Perform falling-head infiltration tests using ASTM-1781 apparatus to obtain infiltration flow data; (ii) Develop computational fluid dynamic (CFD) finite-volume models for different infiltration test conditions; and (iii) Apply appropriate finite-volume model to calculate the effective IBPP infiltration rate under any given surface water depth on the IBPP. Experimental tests were conducted to validate the proposed method.

Woody Encroachment Modifies Subsurface Structure and Hydrological Function

ABSTRACTWoody encroachment—the expansion of woody shrubs into grasslands—is a widely documented phenomenon with global significance for the water cycle. However, its effects on watershed hydrology, including streamflow and groundwater recharge, remain poorly understood. A key challenge is the limited understanding of how changes to root abundance, size and distribution across soil depths influence infiltration and preferential flow. We hypothesised that woody shrubs would increase and deepen coarse‐root abundance and effective soil porosity, thus promoting deeper soil water infiltration and increasing soil water flow velocities. To test this hypothesis, we conducted a study at the Konza Prairie Biological Station in Kansas, where roughleaf dogwood (Cornus drummondii) is the predominant woody shrub encroaching into native tallgrass prairie. We quantified the distribution of coarse and fine roots and leveraged soil moisture time series and electrical resistivity imaging to analyse soil water flow beneath shrubs and grasses. We observed a greater fraction of coarse roots beneath shrubs compared to grasses, which was concurrent with greater saturated hydraulic conductivity and effective porosity. Half‐hourly rainfall and soil moisture data show that the average soil water flow through macropores was 135% greater beneath shrubs than grasses at the deepest B horizon, consistent with greater saturated hydraulic conductivity. Soil‐moisture time series and electrical resistivity imaging also indicated that large rainfall events and greater antecedent wetness promoted more flow in the deeper layers beneath shrubs than beneath grasses. These findings suggest that woody encroachment alters soil hydrologic processes with cascading consequences for ecohydrological processes, including increased vertical connectivity and potential groundwater recharge.

Multi-objective optimization of laser perforated fuel filter parameters based on artificial neural network and genetic algorithm

In precise fuel circuit systems, the filtration of particulate impurities seriously affects the efficiency and service life of various components. For filtration process intensification of high-pressure fuel laser perforated filters, the two-phase flow characteristics in filters is studied. The size, position and number of filtration holes are taken as optimization variables, and take the filtration efficiency and flow pressure drop as optimization objectives. Computational fluid dynamics (CFD) is used to simulate the two-phase motion of continuous phase and discrete particles in a periodic unit. Artificial neural networks (ANN) are utilized for objectives prediction, and the NSGA-II genetic algorithm is employed for multi-objective optimization, resulting in the Pareto front solution set. Furtherly, the reasonable solution is selected by introducing TOPSIS to ensure that two optimization indexes are relatively smaller and balanced. The optimized filter element scheme allows the filter to have a pressure drop of less than 3.2 MPa under high pressure and a filtration efficiency of over 80% for spherical particle impurities with a diameter of 5 microns or more.

Antibacterial bio pores as a river flow filter for the development of "Ndeso Park" water tourism

The realization of the full potential of natural resources in each village for the benefit of the local community has been observed as a significant challenge. The national village-owned enterprises program encourages villages to optimize the utilization of their existing natural and human resources with the objective of fostering their economic independence. The program entails the optimization of the national village-owned enterprises program in the tourism sector, specifically in the context of Taman Ndeso. The objective of this community service activity is to provide technological assistance and address the issue of river water filtration as a pool water source. The impetus for this activity is the declining tourism activities at Taman Ndeso due to the presence of turbid water in the pool, which was deemed unsuitable for use. The activity is realized through the construction of a water purification filtration system to produce clean and healthy water. The antibacterial biopores are applied as filtration technology. This technology is designed to capture bacteria from river water that flow into the pond. This research adopted the direct exploration method, which was divided into a number of stages, including planning and preparation, implementation, evaluation, and reporting. The research outcome manifests into the restoration of the Taman Ndeso water tourism pool, which will be capable of attracting tourists and reviving village income to the maximum extent possible, with the management of the village-owned business entity.

Forces of Filtrate Flow on Podocyte Foot Processes Studied by Three-Dimensional and Two-Dimensional Computational Fluid Dynamics

Forces of Filtrate Flow on Podocyte Foot Processes Studied by Three-Dimensional and Two-Dimensional Computational Fluid Dynamics

The application of PVC hollow fiber ultrafiltration membrane in ultra-low permeability oilfield

Abstract Oil containing wastewater produced from ultra-low permeability oil fields generally needs to be treated to meet the 5-1-1 standard before it can be reinjected. In order to meet the standards for treating oily wastewater in ultra-low permeability oil fields, PVC hollow fiber ultrafiltration membranes and pre-treatment processes for removing oil, suspended solids, sulfides, etc. before the membrane were selected. The application shows that the aeration air flotation flow sand filtration PVC hollow fiber ultrafiltration membrane process can treat oily wastewater, and the treated water can reach the “5-1-1” standard. In the pre-treatment process of PVC hollow fiber ultrafiltration membrane, the silicone rubber membrane aeration device has good oxidation effect, high efficiency in micro nano air flotation for oil removal and suspended solids, and easy management of sand flow filters. This process has economic feasibility and provides technical support for the treatment of oily wastewater in ultra-low permeability oil fields, with great promotional value.

An Implementation of the Particle Flow Filter in an Atmospheric Model

Abstract The particle flow filter (PFF) shows promise for fully nonlinear data assimilation (DA) in high-dimensional systems. However, its application in atmospheric models has been relatively unexplored. In this study, we develop a new algorithm, PFF-DART, in order to conduct DA for high-dimensional atmospheric models. PFF-DART combines the PFF and the two-step ensemble filtering algorithm in the Data Assimilation Research Testbed (DART), exploiting the highly parallel structure of DART. To evaluate the performance of PFF-DART, we conduct an observing system simulation experiment (OSSE) in a simplified atmospheric general circulation model and compare the performance of PFF-DART with an existing linear and Gaussian DA method. Using the PFF-DART algorithm, we demonstrate, for the first time, the capability of the PFF to yield stable results in a yearlong cycling DA OSSE. Moreover, PFF-DART retains the important ability of the PFF to improve the assimilation of nonlinear and non-Gaussian observations. Finally, we emphasize that PFF-DART is a versatile algorithm that can be integrated with numerous other non-Gaussian DA techniques. This quality makes it a promising method for further investigation within a more sophisticated numerical weather prediction model in the future. Significance Statement Data assimilation is an important tool in weather forecasting. However, fundamental issues arising from linear and Gaussian approximations still exist, which can limit our utilization of observations. The particle flow filter is a promising method that avoids these approximations, but efficient algorithms for this method have yet to be developed. In this study, we develop an algorithm for the particle flow filter that can be implemented in high-dimensional geophysical models. We have demonstrated, for the first time, that the particle flow filter runs efficiently for a yearlong experiment in an atmospheric model. The new algorithm also improves the results over a commonly used data assimilation method. The results in this work demonstrate the potential usage of the particle flow filter in the weather forecasting and other high-dimensional forecasting problems.

Numerical Flow Simulations of the Shear Stress Forces Arising in Filtration Slits during Glomerular Filtration in Rat Kidney.

The flow dynamic forces during glomerular filtration challenging the fixation of podocytes to the GBM are insufficiently understood. Numerical flow simulations were used to estimate these forces in the rat kidney. Simulations were run with a 3D model of the slit diaphragm as a zipper structure according to Rodewald and Karnovsky 1. The GBM was modeled as a porous medium. Filtrate flow exerted a mean wall shear stress of 39 Pa with a maximum of 152 Pa on the plasma membrane of foot processes and up to 250 Pa on internal surfaces of the slit diaphragm. The slit diaphragm accounted for 25% of the hydrodynamic resistance of the glomerular filtration barrier. Based on the results of the 3D model, we developed a 2D model that allowed us to perform extensive parameter variations. Reducing the filtration slit width from 40 to 30 nm almost doubled wall shear stress. Furthermore, increasing filtrate flow velocity by 50% increased wall shear stress by 47%. When increasing the viscous resistance of the slit diaphragm, the pressure drop across the slit diaphragm increased to intolerably high values. A lower viscous resistance of the slit diaphragm than that of the GBM accounted for a gradual pressure decline along the filtration barrier. The sub-podocyte space tempered these challenges in circumscribed areas of filtration surface but had only a marginal impact on overall forces. The filtration barrier experiences high levels of shear and pressure stress accounting for the detachment of injured but viable podocytes from the GBM--a hallmark in many glomerular diseases.

Does afforestation increase soil water buffering? A demonstrator study on soil moisture variability in the Alpine Geroldsbach catchment, Austria

This study employed an operational monitoring network to measure soil moisture and runoff behaviour continuously in the Alpine catchment Geroldsbach-Götzens, Austria. We hypothesize that afforestation can have a positive impact on soil water buffering. To analyse the impact of soil properties and vegetation cover changes on soil water dynamics, four experimental plots were established on grassland and monitoring stations were installed in the forest. The rainfall test site is equipped with an automatic weather station to obtain meteorological observations, and weirs to measure surface runoff of natural occurring precipitation events and artificial rainfall simulations. In the plots, 200 soil moisture sensors were installed at five different depths, aimed to track and visualize infiltration and subsurface flow processes. Another twenty sensors monitored soil moisture at different afforestation stages in the forested part of the catchment. The measurements show that soils covered with young and old-growth forest have a higher and more stable soil moisture content than grassland and soils with a lack of vegetation throughout the seasons. We observed large spatial differences at plot scale, where the spatial variability of soil moisture increases with depth and is highest during convective precipitation. The initial conditions and rainfall characteristics play an important role in infiltration processes and soil water storage. Our rainfall test site demonstrated the challenges of innovative monitoring techniques and that it offers opportunities for more experiments to gather evidence-based data as input for flood models. Overall findings confirm the sponge effect of forest soils and indicate that afforestation as Nature-Based Solution reduces the temporal soil moisture variability, buffering soil water during precipitation events, which can be beneficial for runoff reduction in Alpine catchments.

PERIODIC FOAMING DURING SELECTIVE ISOLATION OF HIGHLY PERMEABLE CHANNELS OF POROUS MEDIUM

Selective isolation of watered interlayers by forming barriers formed by highly viscous gels or insoluble precipitates does not always lead to the desired results. Field experience confirms that at some distance from the formed barrier, the filtration flow restores its configuration and the water injected into the formation again moves through highly permeable channels. An increase in the efficiency of flow deflection can be achieved by creating not a single barrier, but a whole sequence of alternating deep-penetrating insulating barriers, separated from each other by a certain distance in highly permeable pores. The paper presents the results of studies of quasi-periodic foaming in order to control mobility under conditions of selective isolation of water in pore channels of high permeability. Foaming occurs due to the in-bulk reaction between concentrated aqueous solutions of gas-generating and gas-generating solutions. Flow pattern of injected aqueous solutions of foaming reagents along current tubes is investigated. The task is to determine the space-time distribution of reagents in given zones of the porous medium. The problem of establishing the correlation between the spatial distribution of the gas formation zone and the dynamics of the gas formation process over time on the one hand, as well as the concentration of reactants, the diffusion rate (mutual diffusion), the gas generation rate and the probability of nucleation on the other hand was solved. The degree of flow blockage in highly permeable zones of the formation depends on the rate of in-situ foam generation and the simulation consists in the fact that it is similar to the law of filtration with a limiting gradient. The paper discusses the process of quasi-periodic gas formation during the movement of mixing solutions in porous media. In stationary filtration in a homogeneous porous medium, the process is described by the proposed system of equations. A system of equations is proposed that describes the movement of a liquid taking into account adsorption of reagents, diffusion and dynamics of the foaming reaction. The results obtained can serve as the basis for developing a method for controlling the water cut of porous media during waterflooding of oil formations. This, in turn, leads to the leveling of the displacement front and an increase in the completeness of coverage.

Abstract P119: The Heart Failure with Preserved Ejection Fraction Induced By High-Fat Diet and L-NAME in Mice Does not Induce a Renal Damage

Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome, without effective therapy, characterized by diastolic dysfunction, a chronic low-grade inflammation and comorbidities such as hypertension. At the present time, few experimental models of HFpEF represent the hallmarks of patients. Recently, it has been described that the administration of a high-fat diet (HFD) in conjunction with an endothelial nitric oxide synthase inhibitor (L-NAME) can adequately reproduce the pathophysiological features of HFpEF. However, the effects on at renal level in HFpEF models have not been fully described. Our goal was to evaluate the kidney damage in a HFpEF model induced by HFD+L-NAME. Male C57BL/6N mice (12 weeks old, n=4-6) were treated with control diet or HFD (60% in fat calories) plus L-NAME (0.65 g/L in drinking water) for 15 weeks. We evaluated cardiac function (echocardiographic analysis), systolic blood pressure (SBP, plethysmography), cardiac and renal hypertrophy (morphometry and histology), plasma creatinine, blood urea nitrogen (BUN), plasma neutrophil gelatinase-associated lipocalin (pNGAL), proteinuria, and kidney immune cells infiltration (flow cytometry). All data are presented by mean±standard deviation. After 15 weeks of HFD+L-NAME we observed diastolic dysfunction (p<0.001), an increased SBP (control=128.0±15.3 vs. HFD+L-NAME=155.7±9.8 mmHg; p<0.01), without changes in ejection fraction and shortening fraction. In addition, we did not observe cardiac or renal hypertrophy, nor apparent histological changes in the renal structure between both groups of animals. No differences were found between groups regarding plasma creatinine, pNGAL or BUN, however, we observed that HFD+L-NAME induced proteinuria in compared to control mice (p<0.05). Finally, when we evaluated the immune cells population in kidney of both groups, we observed no differences in dendritic cells, macrophages, or neutrophils. Nevertheless, the HFD+L-NAME treatment was associated to a significant rising of Ly6G + CD11b - cells population (CD45 + MHC-II - CD11c +/- F4/80 - ) compared to control mice (p<0.05). In conclusion, our results indicate that there is no renal inflammatory damage after 15 weeks of in HFpEF experimental model. However, to our knowledge, an uncharacterized population of Ly6G cells could be participating at this stage which could trigger a long-term renal damage . FONDECYT 1221585 (MPO), 1231604 (JJ), 1231909 (CAA), 11241074 (PA) and FONDAP 15130011(MPO, LG).

Molecularly Imprinted Polyaniline as Solid‐Phase Material for the Extraction of UV Filters From Waters

ABSTRACTSolid‐phase extraction (SPE) using a polyaniline molecularly imprinted polymer (PANI@MIP) is optimized for the extraction of benzophenone‐4 (BP4) from aqueous matrices. First, the three main variables influencing the washing step of the SPE method—type, composition, volume, and percolation flow rate of the washing solvent—were investigated. The optimal conditions for the washing step using the new PANI@MIP‐SPE for maximum retention of BP4 and elimination of interfering molecules (benzophenone‐3 [BP3] and benzophenone [BP]) were determined as follows: 1.25 mL acetonitrile/acetic acid/hexane (45/05/50 v/v/v) as wash solvent at a flow rate of 1 mL min−1. A multiple linear regression model was validated using Student's t‐test to identify the most significant variables affecting this step, including the type and volume of each eluent solvent and the volume of the ternary mixture solvents. The reliability of the model was further confirmed by analysis of variance (ANOVA) and Fisher's F‐test at α = 0.05. The extraction recoveries of the target analyte exceeded 92% over the range of concentrations (from 0.1 to 120 mg L−1), and the maximum retention capacity of PANI@MIP‐SPE was 600 µg g−1, in contrast to 50 µg g−1 for PANI@NIP‐SPE.

Forearm access for carotid artery stenting using the dual protection of flow reversal and distal filter: Trans-forearm dual protection technique.

Although transfemoral carotid artery stenting (CAS) is widely performed for carotid stenosis, serious or even fatal complications such as embolic and access site complications can still occur. We devised a novel dual protection system with continuous flow reversal to the cephalic vein of the forearm in transradial CAS, referred to as the "trans-forearm dual protection" technique. A 75-year-old man with a diagnosis of symptomatic left cervical internal carotid artery (ICA) stenosis underwent CAS using the trans-forearm dual protection technique. A 4F sheath was introduced into the cephalic vein of the right forearm. After an 8F balloon-guiding catheter was navigated into the left common carotid artery (CCA) via right sheathless radial access, a distal filter protection device was advanced into the high cervical ICA. The 8F balloon-guiding catheter was inflated and connected to the 4F sheath with a blood filter interposed. Under the dual protection of flow reversal and distal filter, the CAS procedure was performed. The postprocedural course was uneventful. Diffusion-weighted imaging 2 days after the procedure showed no evidence of ischemic stroke. The patient was discharged home without any complications 1 week after the procedure. Carotid duplex ultrasound performed 9 months after the procedure showed no signs of restenosis. This method allows for CAS under the dual protection of flow reversal and filter device protection via the trans-forearm access, reducing the risk of embolism and access site complications. Therefore, the trans-forearm dual protection technique can be a useful option for CAS.

Geometrical Optimization of Closed-End Cylindrical Air Filter Using CFD Simulation

This research aims to evaluate the effect of porous filter configuration on flow characteristics within filter using CFD simulation. This simulation model was chosen for comprehensive analysis that considers different variables affecting the filter performances. Dynamics of the flow and pressure drop under different flow conditions and filter geometry were studied. The Euler-Lagrangian approach was used to model multiphase flow, and the standard K-ε model was used for turbulence characterisation. Particle size distribution was characterized using Rosin-Rammler distribution. The initial status of these properties was obtained by previous experimental references and their evolution over time was simulated at the cell level of the model using User-Defined Functions (UDF). The main conclusions of the study are: i) The pressure drop increased with flow rate and thickness of the filter but decreased with increasing filter length and diameter. ii) There is no significant change in velocity ratio with the distance from the filter inlet at the filter centre line except the first 5% from the inlet and last 5% close to the end. iii) it was identified that higher radial velocity ratios imply a less particle deposition within the filter media. The results also shows that the particle loading on 290 mm filter is 50% - 60% lower than the other filters but evenly distributed across the filter. However, the pressure drop decreased with the filter length. 55mm filter that has the highest radial velocity ratio performs poorly in particle trapping.

Spatiotemporal distribution patterns of iron, manganese, and arsenic within the river infiltration zone and the potential geochemical activity at key interfaces

The river infiltration zone is a mixed area of surface water and groundwater under the riverbed and along the riverbank, which is greatly affected by river infiltration. Currently, there is a lack of understanding regarding the migration and transformation processes of Fe, Mn, and As, along with their correlation with organic carbon in the river infiltration zone affected by riverbed scouring and siltation processes. In this study, based on techniques such as pore water sampling and the Tessier sequential extraction, the spatiotemporal variations in Fe, Mn, and As concentrations and possible geochemical processes at the riverbed sediment–water interface and along the river infiltration flow path were revealed. The results indicated that the potential geochemical activity of Fe, Mn, and As and the distribution of organic carbon in the riverbed sediment responded to riverbed scouring–siltation processes. Compared to the high water level period, the potential geochemical activity of Fe, Mn, As, and organic carbon in the riverbed sediment generally exhibited an upward trend during the low water level period, indicating more intense Fe and Mn biogeochemical reactions. During river infiltration, the labile organic carbon (LOC) was preferentially utilized, and with increasing depth, the sedimentary organic carbon (SOC) continuously transformed into LOC and dissolved organic carbon (DOC). Affected by riverbed scouring processes, the transition time from oxidizing to reducing conditions in the pore water increased, and the Fe, Mn, and As reduction zones moved deeper and farther from the riverbank, resulting in a significant expansion of the groundwater pollution area. The reductive dissolution of iron and manganese oxides/hydroxides and the oxidation of organic matter–bound Fe, Mn, and As were the main biogeochemical processes contributing to the release of Fe, Mn, and As in the river infiltration zone. These research results have crucial theoretical significance and practical application value for the sustainable utilization of groundwater resources and the remediation of groundwater pollution.

The aminophospholipid transporter, ATP8B3, as a potential biomarker and target for enhancing the therapeutic effect of PD-L1 blockade in colon adenocarcinoma

BackgroundColon adenocarcinoma (COAD) is a prevalent malignant tumor globally, contributing significantly to cancer-related mortality. COAD guidelines label MSI (Microsatellite instability) and MSS (Microsatellite stability) subtypes as global classification criteria and treatment strategy selection criteria for COAD. Various combination therapies involving PD-L1 inhibitors and adjuvant therapy to enhance anti-tumor efficacy. MethodsDatasets from single-cell RNA sequencing and bulk RNA sequencing in the TCGA and GEO databases were utilized to identify differentially expressed genes (DEGs). Furthermore, the correlation between ATP8B3 and PD-L1 was validated using siRNA, shRNA, and western blot analysis. Additionally, the association between ATP8B3 and immune checkpoint blockade (ICB) therapy was investigated through immune infiltration analysis and flow cytometry in both in vivo and in vitro assays. ResultsIn the COAD patient group, ATP8B3 significantly contributed to the establishment of an immunosuppressive microenvironment. Inhibiting ATP8B3 led to a reduction in PD-L1 expression in colon cancer cell lines. Additionally, ATP8B3 expression levels could serve as a potential guide for PD-L1 treatment in MSI-H COAD patients, with higher ATP8B3 expression associated with increased sensitivity to PD-L1 therapy. However, due to the lack of immuno-killer cells in the microenvironment of MSS subtypes, elevated ATP8B3 expression couldn't increase the sensitivity of MSS COAD patients to PD-L1 inhibitors. ConclusionOur research results support that Inhibiting ATP8B3 could enhance TIL (tumor-infiltrating lymphocyte) infiltration by reducing PD-L1 expression in MSI-H COAD, thereby serving as an effective strategy to improve PD-L1 blocker efficacy. The treatment strategy of combining ATP8B3 inhibitors and immunotherapy for MSI/MSS COAD patients will be the best choice.

SURFACTANT–POLYMER FLOODING: GEOCHEMICAL MONITORING OF THE PROPERTIES OF FORMATION FLUIDS AT THE IMPACT AREA

Chemical flooding methods improve oil extraction after standard waterflooding processes. Chemical EOR methods modify different properties of fluids and/or rock to mobilize the remaining oil. It is expected that the residual oil will be different in properties than conventional. A new technology is presented to study a surfactant–polymer flooding, based on a periodic sampling and measuring properties of oil and water during 15 months. The study area is a terrigenous reservoir with 3 chemical injection wells and 16 production wells. High-precision mass spectrometry methods were carried out on each sample, which made it possible to evaluate the effectiveness of ongoing work on chemical flooding. At each sampling date, 2D reservoir model was built to track these changes in the study area. It is shown that the composition of the water has changed - highly permeable channels were closed and formation waters were involved in the production. The properties of oil have also changed - depending on the site of impact, there are areas with more degraded oil in production after the injection of chemicals. Geochemical monitoring shows the redistribution of filtration flow directions in the reservoir volume.

Downflow and upflow sand filtration for removing turbid particles with diverse morphological and surface-charge characteristics: Comparisons of filtered water quality and head loss distribution

Besides the physicochemical characteristics (e.g., size, structure, charge nature, etc.) of turbid particles, the filtration flow direction may affect their migration and adhesion behaviors inside the filtration unit. Unfortunately, there has been a lack of research regarding the combined effects of these above factors on filtered water quality and head loss development during filtration. In this study, different turbid particles were prepared by flocculating water samples containing kaolin and humic acid. Filtration experimental results of these flocculated waters revealed that downflow and upflow filtration modes had different durations of effective filtration under identical PAC-dosage cases, and upflow filtration led to faster increases in filtered water turbidity at the breakthrough stage compared to downflow filtration. During 180-min downflow filtration, the average size of residual turbid particles increased, but this did not occur in upflow filtration. Furthermore, differently from downflow filtration, upflow filtration had a more uniform distribution of head loss across all filter layers. The ease of backwashing differed between the two filtration modes, reflected by the different times required for reaching a relatively stable turbidity during 10-min backwashing. Lastly, based on SEM, FTIR and XPS analyses for characterizing the coagulated particle surface morphology, element composition, and functional groups, a series of conceptual models for particle removal by downflow and upflow filtrations were developed to clarify the influencing mechanisms of different turbid particles on filtration. It highlighted the advantages of upflow filtration, including improved distribution of flow resistance, better removal of larger-sized turbid particles, and enhanced pollutant-holding capacity of the filter media.

RESEARCH OF CROSS-LINKED POLYMER SYSTEMS FOR APPLICATION IN FIELDS CONDITIONS LLC RN-PURNEFTEGAZ

At present time, many oil fields, especially in historically developed areas of oil production, such as Western Siberia, characterized by a mature stage of development, accompanied by a high level of watercut of the produced wells while maintaining significant residual oil reserves. In such conditions, it is necessary to provide for the use of various methods aimed at additional recovery of oil reserves. In particular, it is necessary to provide for the use of tertiary impact methods, a significant share of which is occupied by flow- diverting technologies. The meaning of their application lies in the injection of a small amount of chemical reagents aimed at reducing the permeability of water-washed zones by installing a water-insulating barrier in them and redirecting water filtration flows to previously non-flooded reservoir zones. It should be noted that, unlike most methods of increasing oil recovery, in the case of the use of flow-diverting technologies, the flooding agent does not change — both before and after pumping the rim of chemical reagents, water is used as a flooding agent.From an analysis of literary sources and experience in the use of various types of flow-diverting technologies, it follows that one of the most frequently used technologies, with high versatility of action, is the technology of cross-linked polymer systems based on polymers of the acrylamide series. In this connection, this work presents the results of cross-linked polymer systems studies for selected promising development objects of LLC RN-Purneftegaz. Formulations containing polymers in the concentration range from 0.18 to 1.0 % with the addition of 0,018–0,01 % chromium acetate cross-linker were investigated. Additionally, compositions with the addition of bentonite clay powder in an amount of 0.5 wt.% were studied. A study was carried out of solubility, compatibility with water, crosslinkability of compositions,viscosity properties of initial solutions and crosslinked systems based on them. The thermal stability of cross-linked polymer systems was studied at temperatures from 44 ℃ to 95 ℃ and different mineralization. Recommendations for the use of flow-diverting technologies have been developed.

Methodology for evaluating the effectiveness of system solutions in the oil and gas industry: approaches and practices

This article is dedicated to the study of the degree of development of the system approach in literary sources. The work highlights the issue that the system approach and its individual elements are not sufficiently and fully utilised in activities related to the development of oil reservoirs. The essence of the system approach is identified, stating that it is a method based on considering individual processes and objects in the development of an oil field as interacting and closely interrelated elements. The object of the study is the system approach and the methodology of assessment in its use. Methodology: research of scientific-methodological literature, methods of inductive-deductive reasoning, analysis, synthesis, abstraction, and theoretical generalization. In accordance with the reviewed sources, the following conclusions are drawn: the development and operation of a specific field are carried out according to the type of two-circuit system controlled by enterprise workers and a research institute; it is determined that the most promising approach would be the use of 3D hydrodynamic models, which allow for the consideration of data on vertical exchange processes or filtration flows; the proposed EPS concept minimises inaccuracies in the field of oil and gas science and has a positive impact on the stability and hierarchy of knowledge of subsurface formations, the formation of 3D models based on this, and the accuracy of calculating reserves.