Filtration Characteristics Research Articles

About flooding of low-permeable formations

Due to the depletion of hydrocarbon reserves in traditional reservoirs with good filtration and reservoir properties, there is currently increasing interest in hard-to-recover reserves, and the main difficulty in developing such reservoirs is the efficiency of reservoir pressure maintenance systems. When developing low-permeability reservoirs, various mechanisms of oil displacement during flooding can be distinguished. For reservoirs with permeability less than 1 mD, there is no need to maintain high wellhead pressure; moreover, with a large accumulated compensation, stopping the maintenance of reservoir pressure for up to six months does not lead to a drop in production, which creates the prerequisites for organizing cyclic flooding. This will solve a number of problems that arise while maintaining reservoir pressure when working in such conditions.
 The facies structure of reservoirs sometimes has a decisive influence on the performance of wells and their interinfluence. The transition to the development of fields with a complex geological structure, low filtration characteristics of the formation, the existence of geological bodies with different properties requires not only careful formation of a conceptual understanding of the field, but also the creation of detailed facies digital maps taking into account the existence of zones with different sedimentation, which, as a consequence, creates zones with different filtration and capacitance properties, requiring different approaches to development.

Improving the efficiency of oil field development based on the use of thermochemical treatment technology

The article is devoted to improving the technology of effect the oil reservoir and the bottomhole zone of production and injection wells. Based on laboratory experimental studies, a new technology that allows increasing oil displacement from a porous medium, as well as increasing well productivity has been developed. The composition of the proposed composition includes a strong oxidizing agent, low and trihydric alcohols, surfactants, etc. When the components of the composition interact, an exothermic reaction occurs, as a result of which a large amount of heat and gas are released in the bottomhole zone. Due to the released heat, the viscosity of heavy oil components, deposited in a porous medium and worsening the filtration characteristics of the formation, decreases. As a result of the impact of the composition, the permeability of the bottomhole zone, the productivity of production and injectivity of injection wells increase. Since the exothermic reaction takes place in the formation itself, this allows increasing the thermal effects.

GPF Filtration Characteristics Considering Fractal Characteristics of Particles and Filters

Abstract To reduce the emission of fine particulate matter (PM) from gasoline engines, a gasoline particulate filter (GPF) filtration model that considers the fractal characteristics of both particulate matter and filters is designed and its filtration characteristics are analyzed based on several GPF filtration models. Based on the GPF filtration mechanism, a new mathematical model of fiber efficiency filtration is established after correcting the classical filtration formula based on correcting the particle size of particles and considering the relationship between the porosity of the fiber filter and the fractal dimension of the filter. Simulation of the filtration efficiency of the established mathematical filtration model is carried out to obtain visual filtration efficiency curves. The filtration efficiency and pressure drop of the model are analyzed, and the effects of parameters such as particle fractal dimension, filter fractal dimension, filter thickness, flow rate, and fiber diameter on filtration efficiency are also comprehensively analyzed. The results show that when the fractal dimension of particles is in the range of 1.8-2.8, the most penetrating particle size decreases with the increase of the fractal dimension of particles. When the particle size is small, the effect of fractal dimension on filtration efficiency is not obvious. When the particle size is larger than the most penetrating particle range, the larger the fractal dimension, the filtration efficiency increases obviously. Considering the relationship between the fractal dimension of the filter body and the porosity and the influence of each on the filtration efficiency, the optimal fractal dimension of the filter body should be between 1.82 and 1.925, and the thickness of the filter has some influence on the filtration efficiency. The slower the gas flow rate is, the better the trapping effect will be. However, considering the problem of automobile emission, a lower exhaust speed can be chosen. Increasing the fiber diameter can improve the trapping efficiency of the model, but will reduce the porosity of the trapping collective. Therefore, the fiber diameter should not be too large under the combined action.

Complex of hydrodynamic studies of wells and formations at the Uzen field

The effectiveness of monitoring the development process depends on the availability of complete and high-quality information about the hydrodynamic parameters of productive formations, reservoir reservoir properties, technical condition of wells, etc. The purpose of oil, petroleum gas and reservoir water research is to obtain comprehensive data on their properties and composition, which are within the productive horizons of deposits, as a rule, are fickle. Ignoring the heterogeneity of oil properties over the area of the deposit and the lack of control over changes in physico-chemical properties during the operation of the field can lead to serious errors in predicting the parameters of field development. One of the most important sources of information is hydrodynamic (field) studies of formations and wells. The advantage of hydrodynamic methods for increasing oil recovery is that they are relatively easy to implement and do not require large economic costs. At the Uzen field, the assessment of the initial productive and filtration characteristics of the formations was carried out on the basis of studies of steady-state filtration (MSS) performed during testing of oil-saturated reservoir intervals during exploration and at the initial stage of industrial development of the field when the deposit was operating under natural depletion mode. The article presents the results of a study by the method of steady-state selections (MSS), a study by the method of pressure recovery (PRC).

Sediment Barriers’ Performance in the Laboratory: Evaluation of Clogging and Filtration Characteristics in Geotextiles Subjected to Discharge Cycles

This research aims to assess the clogging process of geotextiles within silt fences. For that purpose, the filtering efficiency, flow rate, and clogging of three geotextiles (GTX-1, GTX-2, and GTX-3) employing two distinct soils and under three sediment discharge cycles were investigated. The analysis adhered to the American standard D5141-11 and, as further analyses, qualitative and quantitative inspections were conducted through microscopic images of the materials. The results showed greater clogging of the nonwoven geotextile, GTX-1, with higher retention efficiency (approximately 100%) and better turbidity removal for both soils, equal to a reduction of around 94%. For GTX-2, a woven geotextile with a larger pore opening, less intense clogging and lower retention efficiency were observed after the third discharge; the average was 96% for both soils. GTX-3, a woven geotextile with a smaller apparent opening, exhibited a behavior similar to GTX-1: as the number of cycles increased, the material experienced more clogging and higher retention efficiency for soil 1 (approximately 98.5%). Based on these findings, it can be inferred that the discharge cycles impact the tested geotextiles in diverse ways and, therefore, the selection of the material should be contingent on project requirements.

Effect of pH, NaCl concentration, and mAb concentration of feed solution on the filterability of Planova™ 20N and Planova™ BioEX.

Virus filtration is one of the most important steps in ensuring viral safety during the purification of monoclonal antibodies (mAbs) and other biotherapeutics derived from mammalian cell cultures. Regarding the various virus retentive filters, including Planova filters, a great deal of data has been reported on the virus retention capability and its mechanism. Along with the virus retention capability, filterability is a key performance indicator for designing a robust and high-throughput virus filtration step. In order to obtain higher filterability, optimization of the feed solution conditions, and filter selection is essential; however, limited data are available regarding the filtration characteristics of Planova filters. Furthermore, for Planova 20N and Planova BioEX, the virus retention characteristics were reported to differ due to their respective membrane materials and layer structures. Whether these filters differ in their filtration characteristics is an interesting question, but no comparative evaluations have been reported. In this study, the filterability of the two filters was investigated and compared using 15 feed mAb solutions of a single mAb selected by design of experiments with different combinations of pH, NaCl concentration, and mAb concentration. The filterability of Planova 20N was affected not only by the feed solution viscosity, but also by the mAb aggregate content of the feed mAb solution and mAb-membrane electrostatic interactions. In contrast, the filterability of Planova BioEX decreased under some buffer conditions. These findings and the established design spaces of these filters provide valuable insights into the process optimization of virus filtration.

Determination of the particularities of the hydraulic friction factor variation of collecting drainage pipelines

The object of the study in this paper is collecting perforated drainage pipelines, in particular, the determination of the hydraulic friction factor λdr, which significantly affects the parameters of the investigated pipes. Clarifying this issue will solve an important engineering problem – to develop a reliable method for hydraulic calculation of collecting perforated drainage pipes. As the main drawback of most of the available theoretical and experimental works on this topic is the insufficient consideration of the filtration characteristics of the surrounding soil and the material of the pipeline walls. Experimental studies of pressure drainage pipes with different design characteristics made it possible to find out the real picture of fluid flow in the pipe. Based on the research results, experimental dependences of λdr on the ratio of the fluid inflow velocity to the average flow velocity in the corresponding section (Uh/V), as well as on the design characteristics of the channel were obtained. The maximum possible flow that can be collected and passed by a collecting drainage pipeline with the specified design and filtration characteristics is determined. It is shown that a larger value of the specified ratio corresponds to larger values of λdr. This result can be explained by the effect of the attached flow on the main flow. Obviously, some energy is spent on the interaction of the attached and the main flow in the pipe, which leads to additional head losses. In the paper, dependencies were obtained for calculating the studied factor for collecting drainage pipelines. Using them in the calculation of drainage pipes will increase the reliability and efficiency of land reclamation systems, in which these pipelines are important structural elements

To the method of distribution drainage pipelines calculation with sloping groundwater level

A methodology for assessing the influence of the error value, which is included in the calculations of distribution pressure drainage pipelines in the case of a groundwater surface slope, is proposed in the paper. It is based on the previously obtained solutions of the system of differential equations describing the liquid movement with variable flow rate in distribution pressure drainage pipelines that operate at the horizontal level of the groundwater surface. The analysis is presented in dimensionless form. The influence of the groundwater level slope on the calculation results is estimated using the value of the relative flow variation in the initial section of the distribution pipeline and the generalized parameter of the distribution drain A, which takes into account its design and filtration characteristics. The obtained calculation formulas are quite simple and easy to use. The proposed method allows to determine the limits within which simplified dependencies for the calculation of drainage pipelines can be used, which are recommended for use at the horizontal groundwater level on the land reclamation site. At the same time, the error introduced into the calculations as a result of the adopted simplification is immediately determined. Corresponding graphs are presented in the paper to illustrate the obtained dependencies.

Study on the construction and filtration characteristics of a Triple-Layer granular bed filter

Granular bed filtration is a high-temperature dust removal technology with unique advantages. In this paper, through the fluidization tests, the densities and granule sizes of the triple-layer filter granules were optimally matched, and a triple-layer granular bed filter was constructed, which could be fluidized in layers and meet the requirement for removing ash deposited in the layers by fluidization without destroying the triple-layer structure. The whole-bed filtration tests at room and high temperatures showed that the triple-layer granular bed filter which consisted of cenosphere layer, desert yellow sand layer and 304 stainless steel shot layer had lower total pressure drop and outlet dust concentration, and higher filtration efficiency than the dual-layer granular bed filter which consisted of cenosphere layer and baozhu sand layer. The separated-bed filtration tests at high temperature found that the upper filter layer experienced the deep-bed, transition and surface filtration periods. The middle and lower filter layers didn’t experience the surface filtration period and the grade filtration efficiency curves were “V” shapes, with the lowest efficiency for particles around 1.3 μm.

Unveiling the Potential: Selecting Optimal Materials for Physical Pools in a Pavement-Runoff-Integrated Treatment System

Pavement runoff contains complex pollutants that can lead to environmental pollution and health risks. A pavement-runoff-integrated treatment system has been recognized as an effective way to deal with pavement runoff pollution. However, there is little support for selecting appropriate materials for physical pools due to a lack of understanding of the selective filtration and physical adsorption characteristics. In this study, gravel and activated carbon were chosen as the substrate materials for physical filtration and adsorption pools, and their corresponding purification characteristics were investigated using an indoor scaled down model. The results showed that the removal rate of all pollutants was related to the size of the gravel used. This was mainly due to the increased gravel particle size and voids, which resulted in a higher water velocity, shorter hydraulic retention time, and inadequate filtration. Compared with coconut shell granular activated carbon (GAC) and coal column activated carbon (EAC), analytically pure granular activated carbon (ARAC) showed a better removal rate for petroleum and heavy metals. This is mainly because ARAC has a larger specific surface area, higher pore volume, and wider pore size distribution, resulting in a remarkable adsorption capacity for pollutants. Overall, the combination of 0.3 mm gravel and ARAC was found to be the most suitable for use as filtration and adsorption materials for physical pools. These findings offer a gravel- and ARAC-based pavement-runoff-integrated treatment system, which has excellent potential to enhance the removal of pollutants from pavement runoff.

Modeling of nonlinear clarification of aqueous suspensions at rapid filters

The basic mathematical problem of nonlinear deep bed clarification of aqueous suspensions at rapid filters is formulated. The results of its solution using exact method for the linear form of the adhesion function and approximate method for the nonlinear form are selectively presented. The derived dependencies are illustrated by parallel exact and approximate calculations of the main filtration characteristics. An estimation of the сalculated errors due to simplification of the original model was carried out indicating the high accuracy of the approximate solution.

Numerical study on filtration characteristics of high-temperature particulate matter in a three-dimensional randomly arranged multi-granularity particle bed filter

The transformation of internal filter granules into a heterogeneous size distribution through abrasion alters filtration properties. This research constructs an abraded multi-granularity particle bed filter via unidirectional coupling of the discrete element method and computational fluid dynamics. The study examined the filtration characteristics of fine particulate matter at high temperatures. The findings indicate that the abraded multi-granularity beds were higher than the uniform size granular beds in both pressure drop and filtration efficiency. The abraded multi-granularity bed enhances filtration efficiency with a proportionally minor increase in pressure drop relative to the uniform size granular bed. In comparison to a stratified bed structure, the mixed configuration of the multi-granularity bed yields greater filtration efficiencies with less escalation in pressure drop. To maintain filtration efficiency beyond 90%, higher temperatures necessitate an augmented inlet flow rate, requiring an increase by a factor of 2.23 at 1000 K relative to 300 K.

Analysis of characteristics of electric field-enhanced multi-gradient of solid particles in oil

Lubricating oil is easily polluted by solid particles, causing it to deteriorate; therefore, solid particles must be separated from the oil. Furthermore, as conventional filtration devices cannot meet both filtration accuracy and service life requirements, an oil and solid separation method for multi-gradient filtration enhanced by an electric field is proposed. A numerical model for multi-gradient separation was established by coupling the governing equations of electric and flow fields, the particle-wall collision equation, and the discrete phase-tracking equation. Enhanced by an electric field, the characteristics of the multi-gradient filtration of solid particles in oil were investigated using finite element method. The effects of the main control parameters on the filtration performance were analyzed. The results indicate that using the electric field-enhanced multi-gradient filtration method can achieve highly efficient separation of solid particles from the oil. When the electric field strength was increased from 0 kV/mm to 2 kV/mm, the deposition concentration of particles was 2.5 times higher and filtration efficiency of the system increased to 97.46%. Additionally, the deposition concentration and filtration efficiency decreased from 0.15 m/s to 0.3 m/s, while gradually increased from 0.3 m/s to 0.5 m/s, for a particle size range of 10–40 µm.

DIGITAL СORE: TEMPERATURE FIELD INFLUENCE ON TWO-PHASE FILTRATION OF FLUIDS IN ROCKS

Link for citation: Katanov Yu.E., Yagafarov A.K., Aristov A.I. Digital сore: temperature field influence on two-phase filtration of fluids in rocks. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 108-118. In Rus. Relevance. Computational fluid dynamics is a powerful tool for studying geological processes. Fluid flow equations in porous media can be solved directly with the resulting three-dimensional X-ray and computer tomographic images. Numerous studies of the geological features of rocks depend on heat transfer in porous materials. These processes include heat conduction in the rock material, convection between matter and the surrounding gas, electrical conductivity, viscous dissipation of fluids, kinetics of chemical reactions, and interfacial heat transfer at the solid/liquid interface. While energy transfer in porous media under conditions of local thermal equilibrium is well studied on the scale of Darcy's law, it is less often considered in porous models. Heat transfer can be accounted for by creating a «heat network» based on a porous network model representing a set of fluid-conducting channels with an appropriate solution to the unified energy balance equation. It is also necessary to take into account convective transfer of thermal energy by the flow of liquid phases (oil, water), each of which is represented by a separate network. Knowing the distribution of the temperature field in the texture of each lithological type of rock, it is possible to determine the probabilistic displacement of the fluid displacement front in the corresponding fluid-conducting space of the rock. Objective: neural network modeling of the effect of the temperature field on the filtration characteristics of hydrocarbons in the fluid-conducting space of rocks. Objects: polymictic sandstones of the Tyumen Formation. Methods. Digital reconstruction of rock texture was performed using artificial intelligence methods and neural networks; neural network algorithms of probabilistic displacement front of two-phase flow (oil, water) were developed in Python programming language; methodical approach to the study of thermal field propagation in rock texture and its influence on two-phase fluid flow was developed using Fourier law, Navier–Stokes equations and similarity criteria of hydrocarbon systems. Results. We developed algorithms for neural network modeling of the temperature field in the fluid-conducting space of a rock (polymictic sandstone) as well as neural network algorithms to estimate the displacement of two-phase filtration front under the corresponding influence of the temperature distribution in the texture of a digital core. The basic mathematical models of these algorithms are outlined. The source code of the algorithms is written in the Python programming language with additional use of non-commercial libraries. The results of neural network modeling have a high degree of reliability, confirmed by experiments with the data obtained in the laboratory of core studies (University of Tyumen, Tyumen), the laboratory of the V.I. Shpilman Research and Analytical Centre for the Rational Use of the Subsoil (Khanty-Mansiysk), laboratory of digital research in oil and gas in the framework of the technological project «Digital core» (Industrial University of Tyumen, Tyumen).

A study on pollutants removal characteristics of domestic riverbed filtration and riverbank filtration intake facilities

A study on pollutants removal characteristics of domestic riverbed filtration and riverbank filtration intake facilities

Application of Machine Learning Methods to Assess Filtration Properties of Host Rocks of Uranium Deposits in Kazakhstan

The uranium required for power plants is mainly extracted by two methods in roughly equal amounts: quarries (underground and open pit) and in situ leaching (ISL). Uranium mining by in situ leaching is extremely attractive because it is economical and has a minimal impact on the region’s ecology. The effective use of ISL requires, among other things, the accurate assessment of the host rocks’ filtration characteristics. An accurate assessment of the filtration properties of the host rocks allows optimizing the mining process and improving the quality of the ore reserve prediction. At the same time, in Kazakhstan, this calculation is still based on methods that were developed more than 50 years ago and, in some cases, produce inaccurate results. According to our estimates, this method provides a prediction of filtration properties with a determination coefficient R2 = 0.32. This paper describes a method of calculating the filtration coefficient of ore-bearing rocks using machine learning methods. The proposed approach was based on nonlinear regression models providing a 20–75% increase in the accuracy of the filtration coefficient assessment compared with the current methodology. The work used different types of machine learning algorithms based on the gradient boosting technique, bagging technique, feed-forward neural networks, support vector machines, etc. The results of logging, core sampling, and hydrogeological studies obtained during the exploration stage of the Inkai deposit were used as the initial data. All used machine learning models demonstrated significantly better results than the old method. This resulted in improved results compared with previous studies. The LightGBM regressor demonstrated the best result (R2 = 0.710).

Combined Method of Intensification of Borehole Uranium Mining in Ores with Low Filtration Characteristics

The purpose of this study is to develop an effective method for increasing the filtration characteristics of ores during borehole uranium mining, depending on the geological characteristics of ores and host rocks. At the same time, it is planned to increase the productivity of production and the pick-up rate of injection wells, increase the period of uninterrupted operation of equipment and reduce operating costs for production. The geotechnological parameters of borehole uranium mining on technological blocks of various mining and geological conditions are investigated and evaluated. Core material samples were taken and the structures and compositions of the host rocks of the Santonian, Maastrichtian and Campanian ore intervals were determined by microscopic method. Based on a comparative analysis of the methods used to intensify borehole production, a combined method for restoring the permeability of the productive horizon was developed. The effective parameters of the combined well regeneration method combining fluctuations of compressed air pulses with chemical reagents – solvents are calculated and justified. The possibility of reducing the processing time of wells by a new method and increasing the productivity of wells is discussed. The method of calculation and application of the combined method of intensification of borehole production of uranium in ores with low filtration characteristics has been developed.

Modified locally derived graphene nanoplatelets for enhanced rheological, filtration and lubricity characteristics of water-based drilling fluids

Drilling fluid rheology, filtration, and lubricity are fundamental parameters that influence the efficiency and ease of drilling operations. The drilling industry is constantly exploring different research areas for stabilizing and improving these parameters at high temperatures. The use of drilling fluid additives, especially synthetic polymers, poses a threat to the environment. Herein, rice husk char (RHC) was used to synthesize graphene Nanoplatelets (GNP) whose surface is modified with triton-X100 nonionic surfactant. Field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), Particle size distribution (PSD), Energy Dispersive X-Ray Analysis (EDX), and Zeta potential analysis are performed on the synthesized nanomaterials to verify their morphology, functional groups, particle size, elemental composition, and material stability. Synthesized GNP from RHC (GNP-RHC) along with surface-modified GNP-RHC (GNP-TXT) were examined critically and their properties compared using a water-based mud (WBM) formulation. The rheological and lubricity characteristics of all the mud samples were determined before and after hot rolling (AHR), and the filtration properties were determined under API and high pressure high temperature (HPHT) conditions. The TGA results indicate that GNP-TXT nanomaterial resists thermal degradation with 10% weight loss at 300 °C, while the zeta potential analysis indicates the materials are stable. Since the GNP-TXT particles are so well dispersed, the GNP-TXT-based muds worked better than the GNP-RHC-based muds and was more stable at controlling filtration and improving rheological properties. For example, at 1.5 g AHR, the plastic viscosity of GNP-TXT-based mud decreased by 22.2% from 9 to 7 cP, while that of GNP-RHC-based mud decreased from 17 to 7 cP by 59%. Also, the API and HPHT FL of WBM of 11 and 24.8 mL, respectively, were reduced by GNP-TXT-based muds to the range of 8.6 and 9.8 mL for API and 18.6 and 22.3 mL for HPHT. However, GNP-RHC-based drilling muds showed a lower fluid loss control of the WBM between 9.6 and 10.2 mL for API and between 19.6 and 23.6 mL for HPHT. Furthermore, the coefficient of friction of the WBM of 0.45 was decreased with GNP-RHC concentrations between 0.47 and 0.32, while GNP-TXT demonstrated a higher decrease between 0.26 and 0.20.

INFLUENCE OF THE CONCENTRATION OF POLYMER SOLUTIONS ON THE FILTRATION PROPERTIES OF RESERVOIRS

The article is devoted to determining the required concentration of the polymer solution that provides the maximum effect of well isolation, depending on the filtration characteristics of the medium. The study was conducted by an experimental method using the methodology of experiment planning. The theory of rational planning was used by varying two variables at five levels. The permeability of the medium and the concentration of the polymer solution were used as variables. Methods of mathematical statistics were used in the processing of the results.

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.