Fluid Filtration Research Articles

Monazite and zircon U[sbnd]Pb and muscovite 40Ar/39Ar geochronology constraints on the timing of magmatism and mineralization in the Huxingshan tungsten deposit, South China

The Huxingshan W deposit (0.21 Mt. WO3 @ 0.3 %) in northeastern Hunan province is located at the western margin of the Jiangnan tungsten belt (JNB), South China. It consists of a series of magma-derived scheelite-quartz-muscovite (SQM) veins in the F1 fault (which contains over 60 % of the W resource), beneath Niutitang Formation (Fm.) carbonate rocks, and above Yijiaqiao Fm. slate (sub-economic), distal from the concealed two-mica granite, which is thought to be responsible for the tungsten mineralization. In this study, we employ LA-ICP-MS zircon and monazite UPb, and muscovite 40Ar/39Ar dating to constrain the timing of magmatism and W mineralization at the Huxingshan deposit. Monazite and zircon dating yield coeval ages of 137.6 ± 0.5 Ma and 138.0 ± 0.5 Ma, respectively. Our muscovite 40Ar/39Ar dating yielded well plateau ages of 132.9 ± 0.6 Ma, 132.2 ± 0.6 Ma, 130.7 ± 0.5 Ma, and 129.7 ± 0.6 Ma for four representative SQM vein ore samples occurring in the Niutitang Fm. carbonate, F1 fault, and Yijiaqiao Fm. slate, indicating multiple pulses of ore-forming fluid infiltration at Huxingshan. Our age data demonstrate that the two-mica granite emplaced at ∼137.6 Ma, significantly earlier than the pulsed W mineralization at ca. 132.9–129.7 Ma. The lack of spatial and temporal association precludes any genetic link between them. Thus, we infer that the ore-forming fluids likely originated from undiscovered deep plutons and ascended through the F1 fault. Besides, our reliable ages coincide with the two periods of large-scale Mesozoic magmatism and W mineralization phases in the JNB, with the 137.6 Ma magmatism falling within the first phase (150–135 Ma), while the W mineralization (ca.132.9–129.7 Ma) falls within the second phase (130–125 Ma). Of which, the second phase, including the Huxingshan, Xianglushang, Dongping, and Jianfengpo deposits, are situated in the western JNB and show further potential in this region.

Distribution and genesis of the Maokou Formation dolomite in Fengdu-Shizhu area, eastern Sichuan Basin

To investigate the development laws and genesis of the Maokou Formation dolomite in the Fengdu-Shizhu area, we analyzed core, thin section, logging, and geochemical data, and obtained the following understandings: 1. The Maokou Formation dolomite includes layered granular dolomite and leopard-spotted limy dolomite which are fine to medium, and moderately euhedral, and have intergranular pores and intergranular dissolved pores; 2. Vertically, the dolomite is the superimposition of multiple stages, 3–12 m a layer and cumulatively up to 30 m. The distribution of the dolomite is controlled by sedimentary cycles and is commonly found in the middle and upper parts of the cycle; 3. The analysis of rare earth distribution and carbon, oxygen, and strontium isotopes indicates that the dolomitizing fluid is the penecontemporaneous saline seawater, and some pore edges were affected by later hydrothermal dolomitization, resulting in recrystallization of dolomite and cementation of saddle-like dolomite; 4. The relationship between the plane distribution of the dolomite and the paleogeographic pattern during the sedimentary period indicates that the dolomite is concentrated in the granular shoals near geomorphic highlands and slope break zones. In summary, it is proposed that the overlap and migration of granular shoals and isolated seawater promoted the occurrence of reflux infiltration of dolomitizing fluid and dolomitization. Multistage granular shoals on the platform margin provide a good material foundation for the development of dolomite. Karstification is conducive to the occurrence of early dolomitization within the shoals and the preservation of pores. It is found that the early dolomite of the Maokou Formation is best developed in the highlands of faults 15 and 16. The basement faults controlled the sedimentary paleogeomorphology, thereby restricting the distribution of dolomite. This understanding provides a new idea for the exploration of dolomite in the Maokou Formation in the Sichuan Basin.

Experimental Investigation of Fracture Propagation in Clayey Silt Hydrate-Bearing Sediments

More than 90% of the natural gas hydrate resources are reserved as marine clayey silt sediments. It is of great significance to efficiently develop a clayey silt hydrate. At present, there are problems of low single well production and small depressurization range in its production test, which is still a long way from commercial exploitation. The combination of hydraulic fracturing technology and other methods such as depressurization method is regarded as one of the potential technical means to achieve the commercial exploitation of the hydrate. However, compared with shale gas reservoirs and coalbed methane reservoirs, clayey silt hydrate reservoirs have special mechanical properties, resulting in unique hydraulic fracturing processes. Therefore, it is necessary to study the fracture initiation and propagation laws of clayey silt hydrate reservoirs. To this end, we carried out large-scale (30 × 30 × 30 cm) true triaxial hydraulic fracturing experiments using a simulated material with similar mechanics, porosity, and permeability to clayey silt hydrate-bearing sediments. The effects of completion method, fracturing method, and fracturing fluid displacement on hydraulic fracture propagation of clayey silt hydrate-bearing sediments were studied. The results showed that a perforated completion can significantly increase the fracture reconstruction area and decrease the fracture initiation pressure compared to an open hole completion. Due to the small horizontal stress difference, it is feasible to carry out temporary plugging fracturing in clayey silt hydrate reservoirs. Temporary plugging fracturing can form steering fractures and significantly improve fracture complexity and fracture area. Increasing the fracturing fluid displacement can significantly increase the fracture area as well. When conducting fracturing in clayey silt hydrate-bearing sediments, the fracturing fluid filtration area is obviously larger than the fracture propagation area. Therefore, it is recommended to use a high-viscosity fracturing fluid to reduce the filtration of the fracturing fluid and improve the fracturing fluid efficiency. This study preliminarily explores the feasibility of temporary plugging fracturing in clayey silt hydrate reservoirs and analyzes the effect of completion methods on the propagation of fracturing fractures, which can provide a reference for the research conducted on the fracturing stimulation of clayey silt hydrate reservoirs.

Effects of Heated Infiltration Solutions and Forced-Air Heating Blankets on Intraoperative Hypothermia During Liposuction: A Factorial Randomized Controlled Trial.

This study was conducted to compare the effects of heat preservation by two recommended methods, heated infiltration solutions and forced-air heating blankets, in patients undergoing liposuction under general anesthesia. Forty patients were divided into four groups based on whether heated infiltration solutions or forced-air heating blankets were used. Group A received general anesthesia liposuction plastic surgery routine temperature care. Based on the care measures of group A, heated infiltration solutions were used in group B; forced-air heating blanket was used in group C; and heated infiltration solutions and forced-air heating blankets were both used in group D. The primary end point was intraoperative and perioperative temperature measured with an infrared tympanic membrane thermometer. Secondary end points included surgical outcomes, subjective experience, and adverse events. Compared with group A, the intraoperative body temperatures of groups B, C, and D were significantly higher, indicating that the two intervention methods were helpful on increasing the core body temperature. Pairwise comparisons of these three groups showed that there was no significant difference between group C and group D. However, using forced-air heating blankets had a marked effect compared with using heated infiltration solutions alone at three time points. The same trend could be seen in other surgical outcomes. Heated infiltration solutions and forced-air heating blankets could reduce the incidence of intraoperative hypothermia and improve patients' prognosis after liposuction under general anesthesia. Compared with the heated infiltration fluid, the forced-air heating blanket may have a better thermal insulation effect. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Strontium concentration spikes as evidence for fluid-driven carbonate dissolution during subduction

Carbonate dissolution, the process by which carbonate minerals are stoichiometrically dissolved by an aqueous fluid, likely plays an important role in liberating carbon from subducting slabs and may thus make significant contributions to global carbon fluxes. It is therefore necessary to understand the fluid infiltration and flow geometries associated with this process. Despite its widespread use as a powerful tracer of fluid-rock interaction, strontium (Sr) has yet to be widely applied to carbonate dissolution scenarios. Previous work has identified a partially altered metacarbonate layer from Syros, Greece, that has undergone significant carbonate dissolution leading to ∼90% CO2 loss (Ague and Nicolescu, 2014). A bulk-rock compositional profile along this layer has a distinctive spike-shaped Sr profile. Sr concentrations are uniform in the altered region behind the reaction front, increase to form a spike just ahead of the front, and taper off to a baseline value moving farther into the unaltered metacarbonate rock. The origin of this type of spike shape and its potential utility for better understanding carbonate dissolution processes remain unaddressed. Here, we present a numerical diffusion-reaction model which demonstrates that both carbonate dissolution and multidimensional transport of Sr, in which the primary advective flow direction is perpendicular to the propagation of the diffusion front, are required to produce this shape. This model, as well as newly acquired Sr concentration data for calcite (former aragonite) and epidote, also indicate that the infiltration of a fluid with an elevated Sr concentration is necessary. We suggest that such spike-shaped features may aid in identifying carbonate dissolution in other settings, such as vein-selvage systems in metacarbonate rocks or reaction rinds on carbonate-bearing mélange blocks.

Analysis of frictionless contact between a spherical indenter and a poroviscoelastic medium with a constant contact radius

The research aims to understand the force relaxation that occurs when a spherical indenter is pressed into poroviscoelastic materials, which exhibit viscoelastic properties of solid network and drainage behavior of infiltrated fluid. To achieve this, an analytical approach is proposed to model spherical indentation on a poroviscoelastic medium under the condition of a constant contact radius. This analysis is conducted in the Laplace-transformed domain, and provides closed-form expressions in the transformed domain for both the normal approach and the contact force of the indenter while maintaining a fixed contact radius. These expressions are then numerically inverse-transformed to the time domain for practical analysis. To account for different scenarios, we consider various combinations of drainage conditions at the top and smoothness conditions at the bottom of the medium. We examine three categories of viscoelastic solid behavior, as understanding how they respond under indentation is crucial for characterizing their mechanical behavior. Additionally, we conduct finite element simulations of spherical indentation on poroviscoelastic media, serving as a comparison to the semi-analytic results obtained. Notably, the thickness of the medium relative to the contact radius and the Poisson's ratio play significant roles in the evolution of both the normal approach and contact force of the spherical indenter over time.

Multiple growth of zirconolite in marble (Mogok metamorphic belt, Myanmar): evidence for episodes of fluid metasomatism and Zr–Ti–U mineralization in metacarbonate systems

Abstract. Fluid infiltration into (meta-)carbonate rocks is an important petrologic process that induces metamorphic decarbonation and potential mineralization of metals or nonmetals. The determination of the infiltration time and the compositional features of reactive fluids is essential to understand the mechanism and process of fluid–rock interactions. Zirconolite (ideal formula: CaZrTi2O7) is an important U-bearing accessory mineral that can develop in metasomatized metacarbonate rocks. In this study, we investigate the occurrence, texture, composition, and chronology of various types of zirconolite from fluid-infiltrated reaction zones in dolomite marbles from the Mogok metamorphic belt, Myanmar. Three types of zirconolite are recognized: (1) the first type (Zrl-I) coexists with metasomatic silicate and oxide minerals (forsterite, spinel, phlogopite) and has a homogeneous composition with high contents of UO2 (21.37 wt %–22.82 wt %) and ThO2 (0.84 wt %–1.99 wt %). (2) The second type (Zrl-II) has textural characteristics similar to those of Zrl-I. However, Zrl-II shows a core–rim zonation with a slightly higher UO2 content in the rims (average of 23.5 ± 0.4 wt % (n=8)) than the cores (average of 22.1 ± 0.3 wt % (n=8)). (3) The third type (Zrl-III) typically occurs as coronas around baddeleyite and coexists with polycrystalline quartz. Zrl-III has obviously lower contents of UO2 (0.88 wt %–5.3 wt %) than those of Zrl-I and Zrl-II. All types of zirconolite have relatively low rare earth element (REE) contents (< 480 µg g−1 for ΣREE). Microtextures and compositions of the three zirconolite types, in combination with in situ zirconolite U–Pb dating using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), reveal episodic fluid infiltration and element mobilization in the dolomite marbles. The first-stage infiltration occurred at ∼ 35 Ma, leading to the formation of Mg-rich silicates and oxides and accessory minerals (Zrl-I, baddeleyite, and geikielite). The reactive fluid was characterized by high contents of Zr, Ti, U, and Th. After that, some Zrl-I grains underwent a local fluid-assisted dissolution–precipitation process, which produced a core–rim zonation (i.e., the Zrl-II type). The final stage of fluid infiltration, recorded by the growth of Zrl-III after baddeleyite, took place at ∼ 19 Ma. The infiltrating fluid of this stage had relatively lower U contents and higher SiO2 activities than the first-stage infiltrating fluid. This study illustrates that zirconolite is a powerful mineral that can record repeated episodes (ranging from 35 to 19 Ma) of fluid influx, metasomatic reactions, and Zr–Ti–U mineralization in (meta-)carbonates. This mineral not only provides key information about the timing of fluid flow but also documents the chemical variation in reactive fluids. Thus, zirconolite is expected to play a more important role in characterizing the fluid–carbonate interaction, orogenic CO2 release, and the transfer and deposition of rare metals.

15-Lipoxygenase promotes resolution of inflammation in lymphedema by controlling Treg cell function through IFN-β

Lymphedema (LD) is characterized by the accumulation of interstitial fluid, lipids and inflammatory cell infiltrate in the limb. Here, we find that LD tissues from women who developed LD after breast cancer exhibit an inflamed gene expression profile. Lipidomic analysis reveals decrease in specialized pro-resolving mediators (SPM) generated by the 15-lipoxygenase (15-LO) in LD. In mice, the loss of SPM is associated with an increase in apoptotic regulatory T (Treg) cell number. In addition, the selective depletion of 15-LO in the lymphatic endothelium induces an aggravation of LD that can be rescued by Treg cell adoptive transfer or ALOX15-expressing lentivector injections. Mechanistically, exogenous injections of the pro-resolving cytokine IFN−β restores both 15-LO expression and Treg cell number in a mouse model of LD. These results provide evidence that lymphatic 15-LO may represent a therapeutic target for LD by serving as a mediator of Treg cell populations to resolve inflammation.

High Respiratory and Cardiac Drive Exacerbate Secondary Lung Injury in Patients With Critical Illness.

The high respiratory and cardiac drive is essential to the host-organ unregulated response. When a primary disease and an unregulated secondary response are uncontrolled, the patient may present in a high respiratory and cardiac drive state. High respiratory drive can cause damage to the lungs, pulmonary circulation, and diaphragm, while high cardiac drive can lead to fluid leakage and infiltration as well as pulmonary interstitial edema. A "respiratory and cardiac dual high drive" state may be a sign of an unregulated response and can lead to secondary lung injury through the increase of transvascular pressure and pulmonary microcirculation injury. Ultrasound examination of the lung, heart, and diaphragm is important when evaluating the phenotype of high respiratory drive in critically ill patients. Ultrasound assessment can guide sedation, analgesia, and antistress treatment and reduce the risk of high respiratory and cardiac drive-induced lung injury in these patients.

Dynamic Effect of Drilling Fluid Filtrate Reducers on Hydrate Formation

Dynamic Effect of Drilling Fluid Filtrate Reducers on Hydrate Formation

Experimental study of hydrophilic additives on filter cake permeability and filtrate losses

AbstractIn the past few years, great emphasis has been placed on developing the water‐based mud system in drilling operations because its properties are suitable for the environment and it is a better choice than oil‐ and synthetic‐based muds. Despite research and development in this field, water‐based muds still have filtration issues that lead to drilling problems, and attempts must be continued in this regard. Therefore, this work aims to reduce the filtrate loss of water‐based mud by affecting the drilling cake and making the permeability as low as possible with enhanced properties that resist the filtration of the drilling fluid. Special care was taken to develop suitable mud rheological properties in terms of plastic viscosity, yield point, and gel strength compared to API standards. To this end, some hydrophilic materials were added to the mud, such as thinners (spersene and trisodium phosphate [TSP]) and some polymers (sodium silicate [SS] and poly acryl amide [PAA] (to compare with the basic mud. The results showed that using thinners and polymers without carboxymethyl cellulose (CMC) and baryte reduced filtrate loss and permeability by a small percentage. On the other hand, adding CMC and baryte to the four additives (spersene, TSP, SS, and PAA) each separately reduced the permeability by 66.1%, 67.7%, 74.1%, and 79%, and reduced filtrate loss by 50.1%, 51.4%, 55.3%, and 58.6%, respectively. It was concluded that adding PAA with CMC and baryte can effectively reduce filtrate losses due to its ability to provide a membrane of low permeability.

Investigation of structural destruction in filtration and flow of heterogeneous fluids)

Investigation of structural destruction in filtration and flow of heterogeneous fluids)

Surface-derived fluid percolation along detachment systems enhanced by syn-kinematic granites: uranium mineralization as an application

Detachment zones are privileged areas for the interaction between surface-derived fluids and rocks, potentially leading to ore deposition. However, the hydrodynamics of detachments and specifically the way by which surface-derived fluids reach crustal depths, remain enigmatic. This question is even more puzzling when the heating caused by the emplacement of a syn-kinematic granite increases the buoyancy of fluids, thus impeding their descent. Here, 2D hydrothermal numerical models are performed. The geometry comprises a detachment and secondary normal faults in the hanging wall. Sensitivity tests were carried out to assess the impact of topographic gradients, syn-tectonic magmatic activity and the depth-dependent permeability contrast between the detachment and the crust. Several flow indicators, integrated over time and combined with particle tracking, enable us to highlight the main controls of fluid circulations. Our study reveals that the infiltration of surface-derived fluids into detachment zones is enhanced by the presence of a heat source at depth, such as a syn-kinematic pluton. Secondary faults are the main percolation path for surface-derived fluids infiltrating the detachment. Plume-like thermal anomalies have been spotted between these faults. The dynamic permeabilities of magmatic intrusions, which depend on sub-solidus temperatures, spatially and temporally reproduce the conceptual model of uranium mineralization in the South Armorican Variscan Domain, which is used as an example.

Structural analysis and optimization of gravity-driven membrane (GDM) for water treatment using computational fluid dynamics (CFD) with open slot implementation

Appropriate cleaning methods are essential to ensure the continuous use of membranes, however, research on the suitable cleaning methods for Gravity-driven membrane (GDMs) remains insufficient. To remove contaminants accumulated on the membrane surface of GDM modules, open slot and non-slot modules were designed and manufactured. These modules were compared for their filtration performance and contaminant removal efficiency through computational fluid dynamics simulations and filtration experiments using influent from wastewater treatment plants (WWTP). While the flow velocity in the housing of the open slot module is slower than that of the non-slot module, flow velocity of 0.17 m/s through the slot can effectively remove sludge accumulated near the beginning of the filtration area, thereby reducing the dead zone. Evaluation of the filtration performance of both modules using influent from WWTPs revealed that flushing effects occurred in both modules for the initial 100 L of filtration, but thereafter, flushing effects were observed only in the open slot module. Therefore, an introducing a slot structure can lead to significant cleaning effects compared to non-slot modules. Therefore, to maintain permeate flux continuously, it is deemed necessary to accompany an appropriate open-slot module for clean-in-place and chemical cleaning.

Simulation of Filter-Cake Formations on Vertical and Inclined Wells Under Elevated Temperature and Pressure

Summary Drilling fluids consist of colloidal suspensions that are made up of solid particles suspended in liquid. The aqueous component of the drilling mud invades a permeable formation due to differential pressure, leaving solid deposits on the drilled formation walls, forming a filter cake. Typical drilling fluids should create a thin, slick filter cake and fluid loss control to seal permeable zones as swiftly as possible. Tight holes, elevated levels of rotational resistance and friction, wellbore obstruction, fluid loss into formations, suboptimal well-log data, and reservoir formation impairment result from thick filter cakes and excessive filtration. Controlling infiltration of fluids to establish a minimal, low-porosity filter cake is frequently required to avoid drilling and production issues. In this study, we used computational fluid dynamics (CFD) to model the development of filter cakes induced by pipe rotation in vertical and inclined wellbore walls under elevated temperature and pressure during deep drilling. Multiple tests validate the basic model for application in both shallow and deep drilling operations. By use of an Eulerian-Eulerian approach to describe drilling fluids as a binary-phase system, including particles in suspension in the non-Newtonian fluid, our research investigates the power-law and Herschel-Bulkley rheological models. These models successfully predict the flow pattern of drilling fluid at the bottom region of deep drilling operations. The study further explores filter-cake formation by examining the influence of overbalanced pressure on filter-cake thickness at various pressures. Drilling simulations, incorporating pipe rotation and eccentricity effects under realistic operating parameters, accurately project filter-cake thickness, aligning closely with experimental measurements and existing CFD literature in this domain.

Little Ironweed and Java Tea in Herbal Toothpaste Reduced Dentine Permeability: An In Vitro Study.

To determine the effect of an herbal toothpaste containing Little Ironweed and Java Tea, on reducing dentine permeability in vitro. Dentine discs from human mandibular third molars were divided into three groups and brushed with herbal toothpaste, nonherbal toothpaste, or deionized water. Each group was immersed in artificial saliva (AS) or 6% citric acid. The permeability of each dentine disc was evaluated before and after saliva or acid challenge using a fluid filtration system. The morphology of dentine discs after treatment was observed using scanning electron microscopy (SEM). The mean permeabilities were statistically analyzed using analysis of variance and Tukey's test. The nonherbal and herbal toothpaste groups demonstrated reduced dentine permeability. AS immersion decreased dentine permeability in both toothpaste groups with values lower than the control group. Dentine permeability values increased after acid immersion in the toothpaste groups and were similar to each other. SEM revealed small granular crystal-like and round particles on the dentine surface and opening of dentinal tubules of both toothpaste groups. More dentinal tubules were opened after brushing with deionized water. The reduction of dentine permeability caused by the herbal toothpaste was similar to that of the nonherbal toothpaste after brushing and the simulated oral conditions. Both herbal plants have the possibility to alleviate clinical hypersensitivity by reducing dentine permeability. Little Ironweed and Java Tea in the toothpaste composition is a potential choice for treating hypersensitive dentine.

Разностная схема повышенного порядка аппроксимации для уравнения Аллера с переменными коэффициентами

The initial boundary value problem for the one-dimensional Aller’s equation with variable coefficients and boundary conditions of the first kind is studied. The problem under study describes the processes of heat transfer in a heterogeneous environment, moisture transfer in soils, and fluid filtration in fractured porous media. To numerically solve the problem posed, a difference scheme of high order of accuracy was constructed - fourth order of accuracy in h and second order of accuracy in τ. Using the method of energy inequalities, an a priori estimate of the solution in a difference treatment is obtained. From this estimate it follows that the solution is unique and stable with respect to the right-hand side and initial data. Under the assumption of the existence of an exact solution to the original differential problem in the class of sufficiently smooth functions, and also due to the linearity of the problem under consideration, the obtained a priori estimate implies that the solution of the constructed difference problem converges to the solution of the original differential problem at a rate equal to the order of approximation of the difference scheme. The goal and scientific novelty of the work is to obtain a new numerical scheme of a higher order of approximation when solving the Dirichlet problem for the Aller’s equation with variable coefficients.

Web Application for Mathematical Modeling of Unsteady Oil Flow in Porous Medium

Introduction. The analysis and interpretation of hydrodynamic research data are based on theoretical models and computational algorithms. Despite the demand for this topic, numerous issues related to unsteady fluid flows in oil reservoirs still require solutions. Therefore, mathematical setting of problems related to the account of unsteady fluid flow, the development of effective numerical methods and algorithms, their solution using modern web technologies are pressing. This study is aimed at developing a web application for mathematical modeling of the process of fluid filtration in single- porosity reservoirs when conducting a hydrodynamic study at a production well.Materials and Methods. To solve the problem, the methods of continuum mechanics and computational mathematics were applied. A model of oil flow in a single-porosity reservoir was presented. Python and JavaScript programming languages were used in the development of the application. The calculation results were stored in a relational database implemented using PostgreSQL tools.Results. A new web application has been developed for modeling the oil filtration process in single- porosity reservoirs. It is applicable for studying fluid dynamic processes and can be used to predict flowrates, production and calculation of optimal well operation modes.Discussion and Conclusion. The developed web application provides for building pressure and temperature fields in the reservoir near a flowing and shut-in production well and at various distances from it. This information makes it possible to urgently assess the duration of hydrodynamic studies, as well as to regulate the operation of wells. The application can be deployed in an existing network infrastructure and use all the functionality by connecting to a remote server. It is optimized for use on various platforms and has broad prospects for further development.

Investigation of the temperature distribution in a heterogeneous reservoir during fluid filtration, taking into account thermodynamic effects

The purpose of the work is to study the temperature field in a formation with heterogeneous permeability during non-stationary non-isothermal two-phase filtration of oil and water, taking into account Joule–Thomson and adiabatic effects. The novelty of the study lies in the establishment of patterns of temperature distribution during two-phase filtration in a formation with heterogeneous permeability, non-monotonic temperature changes associated with two-phase filtration. Numerical experiments have shown that during non-stationary two-phase non-isothermal filtration of water and oil in the bottomhole region of the formation in its heterogeneous zone, temperature formation occurs at different rates in the angular distribution at the initial moments of well operation. In this case, depending on the ratio of the permeabilities of the formation and the heterogeneity zone and on the initial water saturation of the formation, during two-phase filtration in the heterogeneity region relative to the homogeneous one, either a decrease in temperature or, vice versa, an increase in temperature can be observed. The results obtained can be used when interpreting temperature measurement data using multi-sensor borehole equipment in formations with heterogeneous permeability in the presence of multiphase flows, and solving problems of the ecology of freshwater horizons.

Investigation of the temperature field in gas condensate reservoirs taking into account thermodynamic effects

Based on modeling of non-isothermal filtration of a multiphase fluid, taking into account thermohydrodynamic effects and heat of condensation, the formation of a temperature field in a homogeneous porous medium at different pressures at the onset of condensation is studied. A numerical model of one-dimensional two-phase filtration taking into account the phase transition is obtained. Testing of the numerical solution was carried out on the basis of a well-known analytical solution for non-isothermal two-phase filtration in a reservoir taking into account mass transfer. The change in gas flow rate during condensate precipitation and the change in temperature over time on the well wall are considered. It is shown that, depending on the pressure of the onset of condensation (the radius of the onset of condensation in the formation), a different rate of formation of the temperature field in the formation is observed after the well is put into operation: the temperature anomaly can be positive, negative or inverse. The results of numerical experiments can be used when planning field studies in gas condensate wells.