Water-based Fluids Research Articles

Antibacterial Surface Protection using Electrical Discharge Machining with Zinc Tool Electrode for Medical Devices

Electrical discharge machining (EDM), widely used to fabricate medical devices, is applicable for antibacterial surface protection. Silver, transferred from tool electrode or powder suspended in the dielectric to the modified layer during the EDM process, significantly enhanced antibacterial properties of the modified surface. However, bacterial resistance to silver, which was widespread in clinical, still posed challenges for the modified surfaces containing silver.Zinc, owing to its strong antibacterial effects and no challenge related to Zn-resistant bacteria hitherto reported in clinical, was therefore used as tool electrode material to modify Ti6Al4V surfaces during the EDM process. Discharge energies up to 170 µJ with different polarities were applied in the EDM milling process using deionized water-based dielectric fluid. Results show that discharge energy and polarity play a vital role in chemical composition and roughness of the modified surfaces as well as material removal rate and tool wear rate. The surfaces containing zinc contents up to 28 % can be generated. The use of a low energy generates zinc-rich surfaces with less micro-cracks. The EDM process using zinc tool electrode shows a promising potential for antibacterial surface modification of medical devices.

The TLBO algorithm-based optimal heat transfer parameters prediction of Al2O3 water nanofluids in variable pitch corrugated tube heat exchanger

This study investigated an Al2O3 nanofluid water-based tube heat exchanger fitted with a corrugated copper tube under laminar flow conditions. This study is carried out to observe the heat transfer rate within the heat exchanger. The effect of nanoparticle concentrations, the flow rate of the working fluid, and the corrugated tube pitch on the heat exchanger efficiency were analysed. The results show that when Al2O3 water nanofluids are sandwiched between corrugated copper tubes, the heat transfer rate is significantly enhanced compared to the smooth tubes. Nanofluids of Al2O3 were prepared with concentrations of 0.25%, 0.5%, and 1% in deionised water. Corrugated tubes with 25 mm, 20 mm, and 18 mm pitches were fabricated for this investigation. The deionised water and Al2O3 nanofluid-flow rates were maintained at 0.1 m3 per hours, 0.15 m3 per hours, and 0.2 m3 per hours, respectively. Results showed that Al2O3 nanofluids improved the heat transfer rate related to water-based fluids. The highest heat transfer occurred in the 18 mm pitch corrugated copper tube in which 1% nanofluid volume concentration was used as the heat transfer medium. It is observed that the heat exchanger containing corrugated copper tubes with pitch 17.88 mm having 0.98 vol.% of Al2O3 nanofluids, flowing at 0.198 m3 per hour, enhances the heat transfer rate between the working fluids.

Numerical Study of the Thermal and Hydraulic Characteristics of the SiO2–Water Nanofluid through a Backward-Facing Step

The work of this paper is devoted to the two-dimensional numerical investigation of the turbulent forced convection through backward-facing step. Two cases are taken into account. For the first, the bottom wall is smooth; but for the second case, it is corrugated with a triangular base containing ten corrugations. A uniform heat flux is imposed on the bottom wall. A flow of a nanofluid consisting of silicon dioxide SiO2 nanoparticles dispersed in a base fluid (water) flows through this step.The flow equations were discretized by the finite volume method. For modeling turbulence, the K-ɛ-RNG model was applied to analyze Reynolds number effect, the volume fraction and the size of the particle. Numerical simulations were conducted for various Reynolds between 10,000 and 40,000; volume fractions of nanoparticles which vary from 0 to 5% and particle diameter dp equal to 30; 50 and 70 nm. We noted that the obtained findings are in good conformity with those of the literature.

Entropy generation analysis for convective flow of aqua Ag-CuO hybrid nanofluid adjacent to a warmed down-pointing rotating vertical cone

PurposeThis paper aims to study numerically the flow, heat transfer, and entropy generation of aqueous copper oxide-silver hybrid nanofluid over a down-pointing rotating vertical cone, with linear surface temperature (LST) and linear surface heat flux (LSHF), in the presence of a cross-magnetic field. In industrial applications, such as oil and gas plants, food industries, steel factories and nuclear packages, the real bodies may contain nonorthogonal walls and variable cross-section three-dimensional forms which this issue can clarify the importance of selective geometry in the present research.Design/methodology/approachThe mass-based scheme is accomplished for the simulation, and the entropy generation and Bejan number will be analyzed in conjunction with the aforementioned model. It has been hypothesized that two types of boundary conditions (LST and LSHF) as well as five nanoparticle shapes (sphere, brick, cylinder, platelet and disk) present a collection of crucial results. The overseeing PDEs are changed over completely to the dimensionless ODEs, and these are solved by Runge–Kutta–Fehlberg approach combined with a shooting methodology for certain values of physical parameters.FindingsSubsequent to the fantastic compromise of the computational outcomes with past reports, the outcomes are introduced to conduct the investigation of the hydrodynamics/thermal boundary layers, the skin friction and the Nusselt number, as well as entropy generation and Bejan number. A state of hybrid nanofluid, which exhibits a remarkable increase in heat transfer in comparison to the states of mono-nanofluid and regular fluid, has been found to have the highest Nusselt number; however, the skin friction values should always be taken into account and managed. The entropy generation improves with the mass of the second nanoparticle (silver), while the opposite pattern is exhibited for the Bejan number. Furthermore, the lowest value of entropy generation number belongs to the cylindrical shape of nanoparticles in the LST case. In final, a significant accomplishment of the current study is the accurate output of the mass-based scheme for an entropy analysis problem.Originality/valueTo the best of the authors’ knowledge, for the first time, in this study, a new development of natural convective flow of a hybrid nanofluid about the warmed (LST and LSHF) and down-pointing rotating vertical cone by the mass-based algorithm has been presented. The applied methodology considers the masses of base fluid (water) and nanoparticles (Ag and CuO) as an alternative to the first and second nanoparticles volume fraction. Indeed, the combination use of the Tiwari–Das nanofluid model and the mass-based hybridity algorithm for the entropy generation analysis can be the main novelty of this work.

The Effect of Graphene Oxide Biomass as Filtration Loss Control Agent of Water-Based Mud Fluid

The Effect of Graphene Oxide Biomass as Filtration Loss Control Agent of Water-Based Mud Fluid

Mixed convection of two layers with radiative electro-magnetohydrodynamics nanofluid flow in vertical enclosure

Mixed convection flow of two layers nanofluid in a vertical enclosure is studied. The channel consists of two regions. Region I is electrically conducting while Region II is electrically non-conducting. Region I is filled with base fluid water with copper oxides nanoparticles and Region II is filled with base fluid kerosene oil with iron oxides. The simultaneous effects of electro-magnetohydrodynamics and Grashof number are also taken into account. The governing flow problem consists of nonlinear coupled differential equations which is tackled using analytical technique. Analytical results have been obtained by the homotopy analysis method (HAM). The results for the leading parameters, such as the Hartmann numbers, Grashof numbers, ratio of viscosities, width ratio, volume fraction of nanoparticles, and the ratio of thermal conductivities for three different electric field scenarios under heat generation/absorption were examined. It is found that the effect of the negative electric load parameter assists the flow while the effect of the positive electric load parameter opposes the flow as compared to the case when the electric load parameter is zero. All outcomes for significant parameters on velocity and temperature are discussed graphically.

Low-temperature gel breaking fracturing fluid for marine hydrate reservoir fracturing and its effect on phase equilibrium of methane hydrates

Hydraulic fracturing has been proven useful for improving the gas production efficiency of low-permeability hydrate reservoirs. However, no specific fracturing fluid system exists for marine hydrate reservoirs. Applying conventional water-based fracturing fluids in low-temperature (<293.2 K) marine hydrate reservoirs can lead to difficulties in gel-breaking and hydrate instability caused by external additives. In this study, we developed two water-based fracturing fluid systems that exhibited good gel-breaking performance at low temperatures (278.2–288.2 K), one comprising ammonium persulfate (APS), ferrous sulfate (FeSO4), and citric acid (CA), the other APS and triethanolamine (TEA). In addition, we investigated the influence of crosslinking and gel-breaking reactions of the fracturing fluids on the methane hydrate phase equilibrium. The breaking time of the APS-FeSO4-CA system at 278.2K, 283.2K, and 288.2K was 30 min, 75 min, and 120 min respectively. On the other hand, the APS-TEA system accomplished the same task in 3 h, 6 h, and 10 h respectively. Furthermore, methane hydrate phase-equilibrium data showed that the fracturing fluid's three states, base fluid (BF), fracturing fluid gel (FFG), and gel-breaking liquid (GBL), all exerted an inhibitory effect on the phase equilibrium, with the hydrate suppression temperature (ΔT) ranging from 0.4 to 1.0 K. The differences in their inhibitory effect were primarily related to the micromorphology of the hydroxypropyl guar gum (HPG) molecules and the number of active hydroxyl (-OH) groups in the solution. Cryo-scanning electron microscopy (SEM) measurements revealed that the micromorphology of HPG in BF, FFG, and GBL transformed from regular ribbon-like structures to 3-D network structures and then to hole-containing, short ribbon-like structures. FFG formed a regular 3-D network structure after adding crosslinking agents to the BF. The ΔT values reversed from FFG < BF to FFG > BF when the HPG concentration increased from 0.3 wt% to 0.5 wt%, possibly due to the difference in the HPG molecules' water adsorption capacity before and after crosslinking. The broken HPG molecules with OH− groups in the solution were transformed into residues after gel-breaking, decreasing the GBL's inhibitory effect. Therefore, our results indicated that micromorphology variations could cause differences in the HPG molecules' water adsorption capacity, ultimately leading to ΔT differences. Based on our findings, the gel-breaking fracturing fluid systems we developed demonstrated potential for optimizing hydraulic fracturing in marine hydrate reservoirs.

FRACTURING LIQUID DESIGN AND ECONOMIC ANALYSIS FOR LOW PERMEABILITY AND HIGH TEMPERATURE

Mirabelle 01 M01 well is a developed-stage well which has undergone drilling since February 2020 until May 3th 2020. It has 13000 ft depth and dominated with sandstone layers and some shaly inserts. This well is a high temperature (300 F), low permeability (0.5-5 mD) and porosity well which casues hydraulic fracturing should be done in this well. Aim: to carry out fluid fracturing design analysis by considering additional materials and economics. The perforation in this well divided into 2 perforations, first perforation has been 297 ft long and located at 12143 ft-12440 ft of well depth. The second perforation has been 45 ft in length and is located at 12,730 ft-12,685 ft of well depth. Payzone of this well is dominated by sandstone which is determined from the low gamma ray data. This Mirabelle 01 M01 well has high resistivity due to the resistivity log. Water mix used for the formation is a neutral water mix but still has several negative ions with corrosive properties such as SO42- and Cl-. Acid inhibitors are needed to remove these ions and prevent corrosive to be happened. Scale inhibitors are also needed to be added to prevent scale formation caused by Mg2+ ions which are contained in the mix water. From the average pressure calculation, the closure pressure was found about 7914.67 psi. The young modulus found from 8-10 Mpsi which indicates that the formation has high stiffness. The base of the fracturing fluid used is low price water-base fluid with guar gum polymer which can produce hydroxypropilguar (HPG) that don't ruin the formation even if the formation is in the high temperature. Borate ions are used to be crosslinker agents that binds metal ions with polymers. To split polymers molecules, sodium salt from the peroxydisulphate is used to be the gel breaker.

Numerical Simulation for Cooling of Integrated Toroidal Octagonal Inductor Using Nanofluid in a Microchannel Heat Sink

This paper presents a comprehensive numerical simulation study focused on the cooling of integrated toroidal octagonal inductor using nanofluids within a microchannel heat sink. The investigation utilizes COMSOL Multiphysics 6.0 integrated with the Fluid Flow and Conjugate Heat Transfer Module. The primary objective is to explore and understand fluid flow and heat transfer characteristics within the integrated inductor. The study involves testing three distinct fluids, water, CuO-water nanofluid, and Al2O3-water nanofluid, under laminar flow conditions within microchannels. The choice of fluid plays a significant role in heat transfer, interacting with the microchannel geometry to optimize performance. Three-dimensional computational fluid dynamics (CFD) models are meticulously developed; focusing on toroidal inductors equipped with micro pin fins heat sinks. The study commences by detailing the geometry of the micro coil and the integrated heat sink. The simulation encompasses a mathematical model that captures the intricate interplay between the governing Navier-Stokes equations for fluid dynamics and the heat transfer equations within the integrated inductor. As φ increases, temperature, viscosity, and pressure decrease. CuO-water and Al2O3-water nanofluids play a significant role in influencing laminar flow and key thermal parameters in the toroidal inductor. These nanofluids, which consist of base fluids (water) with dispersed nanoparticles (CuO or Al2O3), are employed as cooling agents to enhance heat transfer. The presence of nanoparticles in the fluid alters its thermal properties, leading to changes in the flow dynamics and overall heat dissipation within the toroidal inductor.The laminar flow characteristics are affected by the nanofluid's viscosity, density, and thermal conductivity. Additionally, the Nusselt number, Reynolds number, and thermal resistance are key thermal parameters that reflect the performance of the cooling system. The nanofluid's influence on these parameters is crucial for understanding and optimizing the thermal management of the integrated toroidal inductor. The enhancement of heat dissipation in the toroidal inductor is achieved through improved thermal properties of the nanofluid. Higher nanoparticle concentrations result in better heat transfer rates, leading to lower temperatures in the toroidal inductor. This, in turn, improves the overall efficiency and performance of the cooling system. The viscosity of the nanofluid is influenced by the presence of nanoparticles. The pressure within the microchannels is also affected by the nanoparticle concentration. An increase in φ can lead to changes in pressure drop along the microchannels. Understanding these variations is crucial for designing an effective cooling system.

Fe3+-crosslinked alkyl phosphate ester as thickener for oil-based fracturing fluids

To reduce damage to the formation of water locking and water sensitivity causing poor fracturing effect during the fracturing by water-based fracturing fluid in shale oil and gas reservoirs, the oil-based fracturing fluid as anhydrous fracturing fluid were prepared with dialkyl phosphate (PO(OH)(OR)(OR’)) as gelling agent, complexed iron ion solution as activating agent, n-hexane or kerosene as base fluid. The dialkyl phosphate was synthesized by two-step processes. In the first step, the optimal reaction conditions for preparing monoalkyl phosphate intermediate were the reaction time 5 h, reaction temperature 85 °C, molar ratio of triethyl phosphate to phosphorus pentoxide 3.4:1. In the second step, the optimal synthesis conditions for preparing dialkyl phosphate esters were the reaction time 4 h, reaction temperature 80 °C, molar ratio of the intermediate monoalkyl phosphate esters to the mixed alcohol 1:1.4. Complexed iron ion solution as activating agent was prepared by a consisting of 30 wt% trisodiun citrate, 10 wt% ethanediol, 30 wt% ferric sulfate (Fe2(SO4)3) and 30 wt% deionized water. The effects of gelling agent, activating agent and based fluid on oil-based fracturing fluid performance were examined. The experiments showed that with the increase of gelling agent dosage, the gelation time was significantly shortened and the viscosity gradually increased. When the amounts of gelling agent and activating agent were 2.5 wt% and 4 wt%, respectively, the gelling time and the viscosity of fracturing fluid was up to 166 s and 450 cP. The viscosities of the fracturing fluid were always greater than 100 cP after it was sheared by shear rate of 170 s−1 for 1 h at 80 °C, indicating that the fracturing fluid have good shearing resistance and temperature resistance. The viscosity of the fracture fluid with n-hexane as based fluid was 1.32 cP at 70 °C when the sodium acetate as broken gent was 0.40 wt%, thus the broken gelation effect was remarkable. And the core damage rate of prepared oil-based fracturing fluid was also much lower than that of the common water-based fracturing fluids.

Numerical Simulation of Immersed Liquid Cooling System for Lithium-Ion Battery Thermal Management System of New Energy Vehicles

Power batteries generate a large amount of heat during the charging and discharging processes, which seriously affects the operation safety and service life. An efficient cooling system is crucial for the batteries. This paper numerically simulated a power battery pack composed of 8 lithium-ion cells immersed in the coolant AmpCool AC-110 to study the effects of different coolants, different discharge rates, different coolant mass flow rates, different inlet temperatures and different inlet and outlet settings on the maximum temperature, the maximum temperature difference, the pressure drop, and the required pump power in the battery pack. Among the five coolants studied, W-E in water-based fluids has the best cooling effect, but because of high electric conductivity, it requires special considerations to avoid electric leakage. Increasing the mass flow rate of the coolant can significantly decrease Tmax and ΔTmax, but when the mass flow rate is already high, the decrease is limited and not obvious. Both Δp and the required pump power increase as the mass flow rate increases, and the required pump power increases faster. The inlet temperature will affect the physical properties of the coolant, and choosing the appropriate inlet temperature can not only decrease ΔTmax, but also decrease Δp and the required pump power in the battery pack. The range of 25~27 °C of the coolant AC-110 inlet temperature is recommended. For different inlet and outlet settings, the two-inlet two-outlet setting used in Case 7 has the best cooling effect, and the results indicate uniform distribution is very important to decrease temperature.

Presenting the best correlation relationship for predicting the dynamic viscosity of CuO nanoparticles in ethylene glycol -water base fluid using response surface methodology

The types of correlation relationships by different models for predicting of the dynamic viscosity of CuO nanoparticles (NPs) in the ethylene glycol (EG) (80 %)-Water (20 %) base fluid (BF) by using response surface methodology (RSM) statistical method under temperature conditions of T = 15 to 50 °C, solid volume fractions of SVF = 0.05 to 1 % and shear rate SR = 26.6 to 933.1 s−1 were investigated. Models of Quadratic, Cubic, 2FI and Quartic were investigated. These different models were analyzed based on the measurement criteria such as Correlation deviation, coefficient of determination, standard deviation, reliability and P-values; there are important parameters that were used to compare the models. Among these four models, the Quartic model has been chosen as superior model and used to optimize nanofluid (NF) viscosity. The optimization was done in cold environmental conditions and SVF, T, SR variables and viscosity were selected as minimum values and applied to the system. In the conditions of T = 25.303 °C, SVF = 0.05 % and SR = 26.660 sec-1, most optimal NF viscosity value was 8.565 mPa.sec.

Experimental Study on Thermal Conductivity of Water-Based Magnetic Fluid Loaded with Different Nanoparticles.

Magnetic fluids, a new type of energy transfer fluid with tunable properties, have garnered significant interest from researchers worldwide. Hybrid magnetic fluids prepared by adding different types of nanoparticles exhibit superior thermophysical properties and functional characteristics. In this paper, we prepared a water-based magnetic fluid loaded with multi-walled carbon nanotubes (MCNTs), silver (Ag), and copper (Cu) to enhance thermal conductivity. Using a transient double hot-wire method, we designed and built an experimental measurement system for the thermal conductivity of magnetic fluids with an average measurement error of less than 5%. We studied the thermal conductivity of hybrid magnetic fluids under different conditions and evaluated the advantages and disadvantages of various models, including the Maxwell model, H&C model, Tim model, Y&C model, and Evans model. Our results show that MF+MCNTs, MF+Ag, and MF+Cu nanofluids can all improve the thermal conductivity of the carrier fluid, with MF+MCNTs exhibiting the best improvement effect of 10.93%. Among the five models evaluated, the Evans model had the best predictive effect with a deviation range within 5%. This work provides theoretical and practical reference for enhancing the thermal conductivity of magnetic fluids and provides a more accurate theoretical model for calculating the thermal conductivity of hybrid magnetic fluids.

Comparative investigations of Ag/H2O nanofluid and Ag-CuO/H2O hybrid nanofluid with Darcy-Forchheimer flow over a curved surface

Abstract Nanofluid performed well and produced good results in heat transport phenomena, attracting scientists to suspend other combinations of nanoparticles, called “hybrid nanofluid. Hybrid nanofluids are superior than nanofluids due to their thermal capabilities and emerging benefits that contribute to the boost in the rate of heat transmission. Applications for these nanoparticles, including sophisticated lubricants, are increasing in the fields of bioengineering and electricity. The main prospective of this research is to inquire about the water-based dual nature nanofluid stream numerical simulation through the irregular stretched sheet with heat transfer. In this perspective, silver with base fluid water is used as nanoparticles for nanofluid, and for making hybrid nanofluid, copper oxide and silver particles are used with water-based fluid. Modified Fourier and Fick’s model for heat flux utilized the above phenomenon and observed the heat and mass transport. Similarity variables are needed to transform the partial differential equations into associated nonlinear ordinary differential equations, which are then computationally resolved by the technique of bvp4c which is a built-in function in MATLAB mathematical software. Based on the concurrent approximations, reformations are performed to determine the impact of various quantities on flow variables. The predicted outcomes are depicted in velocity, temperature, and concentration profiles through graphical depiction. The factors indicate that the hybrid nanofluid is more powerful in the transfer of heat than a basic nanofluid because of its superior thermal characteristics. The velocity profile decays for the increasing values of Darcy-Forchheimer parameter. The thermal profile increases for the higher magnitude of Darcy-Forchheimer parameter. The velocity distribution profile increases for the higher values of curvature parameter, while the thermal profile decreases. This unique work might benefit nanotechnology and related nanocomponents. This safe size-controlled biosynthesis of Ag and CuO nanoparticles has resulted in a low-cost nanotechnology that may be used in a variety of applications. Biosynthesized Ag and CuO particles have been used successfully in a variety of applications, including biomedical, antibacterial agents, biological, food safety, and biosensing, to mention a few.

Stability study of aqueous foams under high-temperature and high-pressure conditions relevant to Enhanced Geothermal Systems (EGS)

In Enhanced Geothermal System (EGS) hydraulic fracturing is carried out by injecting cold water into deep Hot Dry Rocks (HDR) under carefully controlled conditions to create new or reopen existing fractures. Water-based fracturing fluids demonstrate some challenges including immense quantity of water usage, water sensitivity of the formations, water blocking, and lack of proppant carrying capacity and transportation. Thus, an alternative is to use foam-based fracturing fluid which offers potential advantage over conventional water-based fracturing fluid such as minimum water usage, reduced wellbore damage, high proppant carrying capacity, and less environmental damage. However, foams are complex mixture of gaseous phase and liquid phase which are thermodynamically unstable at downhole conditions, and their stability can decrease over time due to liquid drainage, bubble coarsening, and coalescence. This paper shows laboratory experiments executed to study foam stability at high temperature (200 °C) and high pressure (6.9 MPa) conditions which simulates the geothermal environment. Foam stability was characterized by half-life of foam, which is defined as the time taken by the foam to decreases by 50% of its original height due to drainage. In this paper, two types of gaseous phases, nitrogen (N2) and carbon dioxide (CO2) were investigated. Also, based on successful practice of foam-based fracturing fluid in oil and gas industries, four surfactants, including Alpha olefin sulfonate (AOS), Sodium dodecyl sulfonate (SDS), Tergitol™ (NP – 40), and Cetyltrimethylammonium chloride (CTAC) at optimum concentration of 1 wt.% were tested for best stability performance. In addition, different stabilizing agents including guar gum, bentonite clay, crosslinker, silicon dioxide nanoparticles (SiO2), graphene oxide (GO) were also studied. Experimental results showed that N2 foams were more stable than CO2 foams. It was observed that foam half-life decreased with the increase in temperature. Among all the surfactants, AOS foams showed the most promising thermal stability at high temperatures. Moreover, with the addition of stabilizing agents, foam's half-life was enhanced. Stabilizing agents such as crosslinker and GO dispersion showed the most stable foams with half-life recorded at 20 min and 17 min, respectively, at 200 °C and 6.9 MPa. Finally, pressure also showed a positive effect on foam stability; with increased pressure, foam half-life was increased. Based on the experimental data, analytical models for the effect of temperature and pressure were developed, considering foam degradation is a first-order kinetic reaction that linearly depends on the foam drainage mechanism. The effect of temperature on foam half-life was studied as an exponential decay model. In this model, foam half-life is a function of drainage rate constant (DA) and activation energy (Ea) of the foam system. The effect of pressure on foam half-life was found to obey a power-law model where an increase in pressure showed an increase in foam half-life. Furthermore, a linear relation was studied for the effect of pressure on foam activation energy and drainage rate. Then the combined effects of temperature and pressure were studied, which yielded an analytical model to predict the foam stabilities in terms of half-life for different foam compositions. This research indicates that with an appropriate selection of surfactants and stabilizing agents, it is possible to obtain stable foams, which could replace conventional water fracturing fluid under EGS conditions.

COMPARISON OF THE EFFECT OF DIFFERENT DIRECT EMULSION EMULSIFIERS ON SYSTEM STABILITY

The use of classical systems on both water and hydrocarbon bases is limited by a number of factors and technological features of such solutions. Hydrocarbon-based drilling muds are non-ecological, have a strong dependence of rheological parameters on temperature, and have a high cost. At the same time, water-based fluids do not have sufficient inhibitory and lubricating properties and increase the risk of problems during well construction. For environmental and economic applications, there is also a type of drilling fluid represented by an oilin- water emulsion of the first type (m/v). Such systems have high technological efficiency compared to abnormally low reservoir pressures, and environmental and economic advantages compared to hydrocarbonbased solution. The initial use of such systems was determined by their use under waterbased solution conditions in order to reduce reservoir repression during drilling. However, such systems also have good hydrophobizing and inhibiting properties, low water loss to the formation and greater environmental friendliness compared to hydrocarbon-based solutions. Such characteristics allow to consider the system refinement to solve the current technological problems in the field of well construction. Experience in the development and use of similar systems is reflected in the works, based on the results of laboratory and field tests, a formulation of a stable emulsion of the 1st type is presented, which includes an aqueous phase saturated with chloride. To determine the possibility of using the systems, pilot tests are carried out for the stability of the system based on various emulsifiers

Mechanism and synergic effect of smart water and amphoteric surfactant on oil recovery in carbonate rocks: Marangoni flow and changing disjoining pressure of water film

One way to increase oil production was to inject various water-based fluids to move oil into the reservoirs, which in some cases used surfactants to produce oil trapped in the water-based fluid, but later found that thess materials can change the wettability of the rock surface to the desired, so various mechanisms have been introduced for them. In this study, using CAPB, CTAB SDS and Triton X-100s surfactants, wettability tests (contact angle), interprocess tension, zeta potential between different procedures, video experiments for Marangoni flow and intrusive vampire tried to explain the primary production mechanism. They are dealt with different reactants. The results showed that the cationic surfactant CTAB, due to its positive ionic charge and the presence of electrostatic forces, approaches the fatty acid groups attached to the rock surface with a negative ionic charge and forms a complex of cationic-anionic ion pairs with them. General condition Compared to cationic surfactants, the performance of anionic surfactants on the change in wettability of carbonate rocks is inferior. This is due to the homonymous electric charge of the oil groups adhering to the rock surface and the anionic surfactants of SDS.

STUDY OF PACKER'S SWELLING RATE IN DIFFERENT LIQUIDS

Cementing is currently the only method used in oil fields to establish zonal isolation. Another method for zonal isolation involves the use of swellable packers. Swellable packers are designed using elastomeric components that have a unique swelling property when exposed to water, water-based fluids or oil. The swelling of the elastomer creates a tight seal. Swellable packers offer several advantages in well construction and maintenance. They can be used for a variety of purposes including preventing gas migration, shutting off water flow, and facilitating fracturing operations. Swellable packer technology involves the selection of elastomers that can expand in the presence of water, oil, or certain brines. It is assumed that the degree of swelling and rate of expansion depends on factors such as elastomer composition, conditions in the wellbore, and the salinity of the surrounding fluids. The use of swellable packers requires careful consideration of well conditions and the fluids present. Matching the packer's swelling properties to the intended well’s fluids is essential to achieve effective zonal isolation. Proper elastomer compatibility testing and evaluation is recommended prior to field deployment to ensure successful and reliable packer operation. in this regard, the purpose of this study is to experimentally confirm the possibility of expanding packers in fluid with different salt concentrations and oil. The study highlights the importance of conducting a comprehensive quality assessment of elastomers prior to their use in field operations. Keywords: cementing, zonal isolation, swellable packers, swelling property, salinity, elastomers, crude oil, swelling rate.

Hole quality improvement in CFRP/Ti6Al4V stacks using optimised flow rates for LCO2 and MQL sustainable cooling/lubrication

Carbon fibre reinforced polymer/titanium stacks (CFRP/Ti6Al4V) are employed in aeronautics due to their excellent weight-to-strength ratio and corrosion properties. However, these same material properties present challenges for hole making which cannot be solved using conventional water-based metalworking fluids (MWFs), as they cause degradation of the composite. Moreover, environmental and health concerns require exploration of alternative cooling/lubrication solutions. In this study, a controlled mixture of liquid carbon dioxide (LCO2) and minimum quantity lubrication (MQL) was supplied through the drilling tool. The effect of varying LCO2 and MQL flow rates was evaluated on cutting forces, temperatures, and several hole quality outputs. The optimal flow rates were then determined through multi-objective optimisation. The results show that the cooling/lubrication flow rate greatly affects the measured outputs, and that supplying LCO2 + MQL with optimised flow rates helps achieve superior quality holes in CFRP, Ti6Al4V and CFRP/Ti6Al4V stacks.

Numerical studies on the effects of melting heat transfer over quadratic radiative-magnetic hybrid nanofluid flow toward a porous shrinkable surface influenced by second-order slip velocity: Stability analysis and entropy generation

ABSTRACT The exclusive behavior of hybrid nanofluid flow and heat transmission properties through a porous medium toward a porous shrinking surface along with the external magnetic field, melting heat transfer, and second-order slip is investigated in this study. Moreover, the effects of a porous medium and quadratic thermal radiation are also incorporated. Molybdenum disulfide () and silicon dioxide () are hybridized as a very dilute homogenous mixture in the base fluid water (). Nonlinear partial differential equations with specified boundary constraints are transformed into a set of nonlinear ordinary differential equations using similarities transformation before being solved numerically with the help of default solver by bvp4c technique in MATLAB programming. This work is distinctive because it presents a novel hybrid nanofluid mathematical model with multiple (lower and upper) solution branches for the shrinking case within the defined ranges of the physical parameters. The temporal stability analysis shows that only one solution is stable as time evolves. The results are shown as velocity and temperature curves, skin friction coefficient, and local Nusselt number in the form of tabulated data and graphical structures. The heat for quadratic thermal radiation and melting heat transfer parameters contribute to the progress of thermal enhancement. Furthermore, by combining silicon oxide with a volume percentage of molybdenum disulfide, the flow is retarded, and heat transfer is enhanced. Entropy formation is considerably enhanced by quadratic thermal radiation and nanoparticle solid volume fraction parameters. In engineering, hybrid nanofluid has many uses, including in cosmetics, fabrics, paper plastics, automobiles, soaps, food packaging, food colorants, homes, cancer treatment, pharmaceuticals, ceramics, and paints.