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This paper presents an experimental investigation of the displacement characteristics of a hydrostatic spindle used in a medium-sized circular grinding machine. The study focuses on the influence of lubricant pressure and oil viscosity on spindle displacement under varying load conditions. Experiments were conducted using a specially designed testing bench, which allowed precise control of pump pressure and oil viscosity. The results demonstrate a significant impact of both parameters on spindle displacement. An increase in oil viscosity leads to a decrease in displacement, with the optimal viscosity identified as 2 mPa.s. Similarly, higher pump pressure results in reduced displacement, with 5 MPa being the optimal pressure for the system studied. These findings highlight the importance of carefully selecting lubricant properties and operating conditions to achieve optimal machining accuracy and stability. This research provides valuable insights into the understanding and optimization of hydrostatic bearing systems in precision machining applications. [ABSTRACT FROM AUTHOR]

The study of the law and degree of injection and extraction coupling in old oil areas is a difficult point that affects the recovery rate. The traditional experimental and numerical simulation research methods lack validation and working condition prediction. This study has improved the working steps and supplemented the lack of program validation link through the methods of data prediction and mathematical argumentation. This program has been implemented in the Tamkou field. In addition, we determined the relationship between different permeability, crude oil viscosity, and recovery rate influencing factors on recovery under the premise of a fixed well network, and the DGM (1,1) model prediction yielded the recovery rates of 8.93 and 12.08 for the next 2 time nodes. The analyses showed that adopting the means of water blending and dosing to adjust the crude oil viscosity to 90 mPa s, and adopting the water injection rate of 5 mL/min to extract the best recovery rate. Min water injection rate is optimal for extraction. [ABSTRACT FROM AUTHOR]

This study investigates the effect of oil viscosity on pollutant emissions and fuel consumption of an internal combustion engine (ICE) at high altitudes using a response surface methodology (RSM). A Chevrolet Corsa Evolution 1.5 SOHC gasoline engine was used in Cuenca, Ecuador (2560 m above sea level), testing three lubricating oils with kinematic viscosities of 9.66, 14.08, and 18.5 mm2/s, measured at a temperature of 100 °C under various engine speeds and loads. Key findings include the following: hydrocarbon (HC) emissions were minimized from 150.22 ppm at the maximum load to 7.25 ppm with low viscosity and load; carbon dioxide (CO2) emissions peaked at 15.2% vol with high viscosity and load; carbon monoxide (CO) ranged from 0.04% to 3.74% depending on viscosity and load; nitrogen oxides (NOx) were significantly influenced by viscosity, RPM, and load, indicating a need for model refinement; and fuel consumption was significantly affected by load and viscosity. RSM-based optimization identified optimal operational conditions with a viscosity of 13 mm2/s, 1473 rpm, and a load of 78%, resulting in 52.35 ppm of HC, 13.97% vol of CO2, 1.2% vol of CO, 0 ppm of NOx, and a fuel consumption of 6.66 L/h. These conditions demonstrate the ability to adjust operational variables to maximize fuel efficiency and minimize emissions. This study underscores the critical role of optimizing lubricant viscosity and operational conditions to mitigate environmental impact and enhance engine performance in high-altitude environments. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Petroleum Research & Studies is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the results of experimental tests of the efficiency of a single-stage worm gear. Two worm drives were used for testing, where the worms are made of improved steel 42CrMo4 and the worm gears are made of tin bronze CuSn12 and aluminium alloy A356. The values of the efficiency were determined at different values of revolutions and loads, where oils of different viscosities were used for lubrication. Determining the efficiency, the coefficient of friction of worm drives was calculated for experimental operating conditions, as well as the mass measurement of worm gears before and after testing. Based on the experimental results, depending on the operating mode and oil viscosity, the values of the efficiency of the worm drive made of the material 42CrMo4/CuSn12 are higher by 5 to 9 % compared to the worm drive 42CrMo4/A356. Higher values of the efficiency of the worm drive 42CrMo4/CuSn12 cause lower values of the coefficient of friction by 14 to 21 % as well as less wear of the worm gears.

A simulated oil viscosity prediction model is established according to the relationship between simulated oil viscosity and geometric mean value of T2 spectrum, and the time-varying law of simulated oil viscosity in porous media is quantitatively characterized by nuclear magnetic resonance (NMR) experiments of high multiple waterflooding. A new NMR wettability index formula is derived based on NMR relaxation theory to quantitatively characterize the time-varying law of rock wettability during waterflooding combined with high-multiple waterflooding experiment in sandstone cores. The remaining oil viscosity in the core is positively correlated with the displacing water multiple. The remaining oil viscosity increases rapidly when the displacing water multiple is low, and increases slowly when the displacing water multiple is high. The variation of remaining oil viscosity is related to the reservoir heterogeneity. The stronger the reservoir homogeneity, the higher the content of heavy components in the remaining oil and the higher the viscosity. The reservoir wettability changes after water injection: the oil-wet reservoir changes into water-wet reservoir, while the water-wet reservoir becomes more hydrophilic; the degree of change enhances with the increase of displacing water multiple. There is a high correlation between the time-varying oil viscosity and the time-varying wettability, and the change of oil viscosity cannot be ignored. The NMR wettability index calculated by considering the change of oil viscosity is more consistent with the tested Amott (spontaneous imbibition) wettability index, which agrees more with the time-varying law of reservoir wettability. [ABSTRACT FROM AUTHOR]

It is established that within the temperature range of oil dehydration in the fields, a phase transition occurs in oils, accompanied by a multifold change in the particle size of their dispersed phase. The study examines the method of assessing the temperature T* at which this process occurs based on the temperature dependence of oil viscosity. It is found that with T>T*, there are two effects taking place in oils that change the stability of oil-water emulsions in two opposite directions. Specifically, the reduction of oil viscosity facilitates a decrease in emulsion stability. In turn, increased emulsion stability is promoted by a rise in the content of natural emulsifiers in the oil disperse medium at T>T* due to a phase transition with a dramatic change in the particle size of the disperse phase. Therefore, the maximum speed and degree of oil dehydration is achieved at T*, which is confirmed experimentally. As a result, the need for a critical analysis of the oil treatment temperature regime used in the fields considering phase transitions within the particles of its dispersed phase is shown.

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the effect of oil viscosity on pollutant emissions and fuel consumption of an internal combustion engine (ICE) at high altitudes using a response surface methodology (RSM). A Chevrolet Corsa Evolution 1.5 SOHC gasoline engine was used in Cuenca, Ecuador (2560 m above sea level), testing three lubricating oils with kinematic viscosities of 9.66, 14.08, and 18.5 mm2/s, measured at a temperature of 100 °C under various engine speeds and loads. Key findings include the following: hydrocarbon (HC) emissions were minimized from 150.22 ppm at the maximum load to 7.25 ppm with low viscosity and load; carbon dioxide (CO2) emissions peaked at 15.2% vol with high viscosity and load; carbon monoxide (CO) ranged from 0.04% to 3.74% depending on viscosity and load; nitrogen oxides (NOx) were significantly influenced by viscosity, RPM, and load, indicating a need for model refinement; and fuel consumption was significantly affected by load and viscosity. RSM-based optimization identified optimal operational conditions with a viscosity of 13 mm2/s, 1473 rpm, and a load of 78%, resulting in 52.35 ppm of HC, 13.97% vol of CO2, 1.2% vol of CO, 0 ppm of NOx, and a fuel consumption of 6.66 L/h. These conditions demonstrate the ability to adjust operational variables to maximize fuel efficiency and minimize emissions. This study underscores the critical role of optimizing lubricant viscosity and operational conditions to mitigate environmental impact and enhance engine performance in high-altitude environments.

Radial slide bearings are typically used in turbochargers (among other applications), owing to their simple design and advantages, such as good heat dissipation from the working zone, high stability of operation and low resistance to motion. The current research is both experimental and theoretical. In a state of static equilibrium, the operation of a bearing can be described using a system of five coupled differential equations. The bearing’s operating parameters are related to the type of oil used. Two types of oil, VG46 and VG68, were used for testing. In accordance with the applicable standard, the tolerance of kinematic viscosity of oils is ±10%. The results imply a significant influence of the oil class and viscosity tolerance on the resistance to motion caused by internal friction forces in the oil. In conclusion, it seems advisable that the calculation procedures currently in use should include the slide bearing design optimisation by taking the resistance to motion in the bearing into account.

The integrated design of the motor and axial piston pump eliminates the coupling structure, resulting in a compact and lightweight motor-pump structure. The challenge of motors overheating has always been a major concern. To address this issue, the hydraulic oil throughout the motor pump is utilized for cooling the high-speed motor, effectively improving the power density and heat dissipation capability of the hydraulic power unit. This integrated design approach has successfully resolved the significant issue of overheating motors, leading to enhanced performance of the hydraulic power unit. To address this concern, the entire motor pump's oil is utilized to cool the high-speed motor. Consequently, the thermodynamic prediction of high-speed motor pumps has become increasingly important. In this study, the impact of motor heat generation on hydrodynamics is analyzed, and the heat transfer of the motor pump is investigated using the control volume method. Furthermore, thermodynamic models of hysteresis loss, eddy current loss, alternating current loss, churning loss, and throttling loss are established for the oil-immersed motor pump. The change in oil viscosity is also considered. The instantaneous temperature change rule of the oil within the oil-immersed motor pump is derived. Additionally, the influence of various working conditions such as pressure and speed on the temperature of the motor pump's key node is examined. The experimental results indicate the accuracy of the thermodynamic calculation, and the significant effect of motor loss on the leakage temperature. [ABSTRACT FROM AUTHOR]

This article focuses on the quality of hemp oil processing, specifically the filtration that is an important part of the technological procedure of processing vegetable oils. The aim of the research was to determine the effects of pressure and temperature on the filtration parameters when using plate filters. The research was carried out on an experimental measuring device with adjustable static pressure. The qualitative properties of the oil were observed in terms of analytical composition, microbial content, and changes in peroxide value as the indicator of oxidation stability. The change in pressure affected the oil flow rate, especially at lower pressure values. The increase in temperature of the filtered oil had a negative impact on the oxidation stability. [ABSTRACT FROM AUTHOR]

Pressure gradient of a two phase mixture in a horizontal pipe were experimentally investigated for water/super viscose oil mixtures. The mixture contained oil having a viscosity of 67 cp and density of 0.872 g/cm3, and pure water, flowing through an acrylic pipe having a length and diameter of 6 m and 20 mm, respectively. A high speed digital camera has been used to record visual information. Superficial velocities of water and oil were in the range between 0.18–1.2 m/s and 0.18–0.95 m/s, respectively. The experimental pressure gradient has been compared to the Al-Wahaibi correlation and two-fluid model. The absolute average error for the “two-fluid model” and Al-Wahaibi correlation have been calculated for 30% and 12%, respectively. In this investigation, a new modified correlation is developed on the basis of the Al-Wahaibi correlation, that predicts the values of pressure gradient with an absolute average error of about 9%. The pressure gradient correlation was validated extensively against 11 independent data sources. To our knowledge, this is the best pressure gradient furmola that is published for oil–water flow which includes wide range of operational conditions including fluid properties, pipe diameters and pipe materials. One of the advantages of the new proposed formula is that it also performs well for super viscosity oils.

Radial slide bearings are typically used in turbochargers (among other applications), owing to their simple design and advantages, such as good heat dissipation from the working zone, high stability of operation and low resistance to motion. The current research is both experimental and theoretical. In a state of static equilibrium, the operation of a bearing can be described using a system of five coupled differential equations. The bearing's operating parameters are related to the type of oil used. Two types of oil, VG46 and VG68, were used for testing. In accordance with the applicable standard, the tolerance of kinematic viscosity of oils is ±10%. The results imply a significant influence of the oil class and viscosity tolerance on the resistance to motion caused by internal friction forces in the oil. In conclusion, it seems advisable that the calculation procedures currently in use should include the slide bearing design optimisation by taking the resistance to motion in the bearing into account. [ABSTRACT FROM AUTHOR]

To explore the synergistic mechanism of polymer and surfactant in the binary combination flooding of low-permeability reservoirs, the adaptability experiment of polymer salt-resistant partially hydrolyzed polyacrylamide and nonionic surfactant was carried out in the indoor system. Experiments at different ratios are also performed. The results show that the selected poly/surface binary flooding system increases with the concentration of polymer or surfactant, the viscosity of the poly/surface binary system also increases and, at the same time, has better temperature and salt resistance. The viscosity of the binary system will decrease when the salinity increases. When the surfactant concentration CS = 0.2% and the polymer concentration CP = 0.2%, the viscosity of the system is the highest. The viscosity of the poly/table binary system at different concentrations decreases when the temperature rises: pure polymer (CP = 0.2%), poly/table binary system displacement fluid CP = 0.1% + CS = 0.2% and CP = 0.2% + CS = 0.2%; and the injection pressure first rises and then drops. The final recovery rate is 51.8%, which meets the development of most oil reservoirs.

The integrated design of the motor and axial piston pump eliminates the coupling structure, resulting in a compact and lightweight motor-pump structure. The challenge of motors overheating has always been a major concern. To address this issue, the hydraulic oil throughout the motor pump is utilized for cooling the high-speed motor, effectively improving the power density and heat dissipation capability of the hydraulic power unit. This integrated design approach has successfully resolved the significant issue of overheating motors, leading to enhanced performance of the hydraulic power unit. To address this concern, the entire motor pump’s oil is utilized to cool the high-speed motor. Consequently, the thermodynamic prediction of high-speed motor pumps has become increasingly important. In this study, the impact of motor heat generation on hydrodynamics is analyzed, and the heat transfer of the motor pump is investigated using the control volume method. Furthermore, thermodynamic models of hysteresis loss, eddy current loss, alternating current loss, churning loss, and throttling loss are established for the oil-immersed motor pump. The change in oil viscosity is also considered. The instantaneous temperature change rule of the oil within the oil-immersed motor pump is derived. Additionally, the influence of various working conditions such as pressure and speed on the temperature of the motor pump’s key node is examined. The experimental results indicate the accuracy of the thermodynamic calculation, and the significant effect of motor loss on the leakage temperature.

This study aims to determine the effect of holding time and oil viscosity on the S45C steel hardening process on the corrosion rate. The corrosion rate is measured using the weight loss method. Micro-photo observations of the S45C steel surface were carried out to determine the type of corrosion. The results demonstrate that the corrosion rate of hardened S45C steel decreases following the longer holding time during hardening. In addition, the corrosion rate of hardened S45C steel decreases when the viscosity of the oil used during hardening is thicker. Finally, the type of corrosion is uniform and pitting corrosion. [ABSTRACT FROM AUTHOR]

FeCuC sintered steel is prone to rust, therefore rust preventive oil is used for storage. These rust preventive oils generally have a problem of reduced workability due to stickiness caused by high viscosity. However, few electrochemical studies have been conducted on the correlation between viscosity and corrosion resistance. Therefore, in this study, we investigated the effect of the base oil viscosity on the corrosion resistance of rust preventive oil by changing the base oil viscosity. As an experimental method, electrochemical measurements were carried out using the water screen test established in our laboratory, which can quantitatively evaluate the rust preventing ability. According to the polarization curves measurements, corrosion current density Icorr is reduced by coating the rust preventive oil. It showed about 100,000 times better corrosion resistance with and without rust preventive oil. While, almost no difference in rust preventive ability was confirmed due to the difference in base oil viscosity. According to the results of the open circuit potential, the time required for the potential of FeCuC sintered steel to saturate was 505 ks for low viscosity, 651 ks for medium viscosity, and 340 ks for high viscosity. Therefore, it was found that there is no correlation between the time until rust occurs and the viscosity of the oil film. It was also found that the effects of the additives were fully exerted even if the oil viscosities were different. Therefore, the problem of reduced workability due to stickiness can be solved by using low viscosity base oil. [ABSTRACT FROM AUTHOR]

After a sandstone oilfield enters the high water-cut period, the viscosity of crude oil has an important influence on remaining oil distribution and waterflooding characteristics under the same factors of, e.g., reservoir quality and development methods. Based on a comprehensive interpretation of the waterflooded layers in new oil wells, physical simulation experiments, and reservoir numerical simulations, we analyzed the waterflooding laws of a high water-cut sandstone reservoir with different oil viscosities in Kazakhstan under the same oil production speed, and we clarified the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The results show that low-viscosity oil reservoirs (1 mPa s) have uniform waterflooding, thick streamlines, small waterflooding areas, and low overall waterflooding degrees because of their homogeneous oil–water viscosities. However, within waterflooded areas, the reservoirs have high oil displacement efficiencies and high waterflooding degrees, and the remaining oil is mainly concentrated in the unwaterflooded areas; therefore, the initial production and water cut in new oil wells vary significantly. High-viscosity oil reservoirs (200 mPa s) have severe waterflooding fingering, large waterflooding areas, and high overall waterflooded degrees because of their high oil–water mobility ratios. However, within waterflooded areas, the reservoirs have low oil displacement efficiencies and low waterflooding degrees, and the remaining oil is mainly concentrated in both the waterflooded areas and the unwaterflooded areas; therefore, the differences in the initial production and water cut of new oil wells are small. Moderate-viscosity oil reservoirs (20 mPa s) are characterized by remaining oil distributions that are somewhere in between those of the former two reservoirs. Therefore, in the high water-cut period, as the viscosity of crude oil increases, the efficiency of waterflooding gradually deteriorates and the remaining oil potential increases. In the later development, it is suggested to implement the local well pattern thickening in the remaining oil enrichment area for reservoirs with low viscosity, whereas a gradual overall well pattern thickening strategy is recommended for whole reservoirs with moderate and high viscosity. The findings of this study can aid better understanding of waterflooding law and the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The research results have important guidance and reference significance for the secondary development of high water-cut sandstone oilfields.

Pressure gradient of a two phase mixture in a horizontal pipe were experimentally investigated for water/super viscose oil mixtures. The mixture contained oil having a viscosity of 67 cp and density of 0.872 g/cm3, and pure water, flowing through an acrylic pipe having a length and diameter of 6 m and 20 mm, respectively. A high speed digital camera has been used to record visual information. Superficial velocities of water and oil were in the range between 0.18-1.2 m/s and 0.18-0.95 m/s, respectively. The experimental pressure gradient has been compared to the Al-Wahaibi correlation and two-fluid model. The absolute average error for the "two-fluid model" and Al-Wahaibi correlation have been calculated for 30% and 12%, respectively. In this investigation, a new modified correlation is developed on the basis of the Al-Wahaibi correlation, that predicts the values of pressure gradient with an absolute average error of about 9%. The pressure gradient correlation was validated extensively against 11 independent data sources. To our knowledge, this is the best pressure gradient furmola that is published for oil--water flow which includes wide range of operational conditions including fluid properties, pipe diameters and pipe materials. One of the advantages of the new proposed formula is that it also performs well for super viscosity oils. [ABSTRACT FROM AUTHOR]

In this paper, the effects of clearance between piston and cylinder and oil viscosity index on the friction of area between the piston and cylinder of an internal combustion (IC) engine were investigated experimentally and theoretically. To this end, two values of 33 and 66 µm for the piston clearance, and two types of engine oil namely SAE10W40 and SAE20W50 were considered. To carry out the experiments, the engine was run under motored condition. The experiments were implemented at different oil temperatures and engine speeds. Based on the experimental results, although reduction in the piston clearance and the use of 20W50 oil caused an increase in the friction, but the effects of these two parameters became less with an increase in oil temperature and engine speed. The experimental results showed that the effect of clearance on the friction was more noticeable for low speeds. The maximum influence of the piston clearance decrease on the friction was 16% with the use of 20W50 oil at 1000 r/min when the oil temperature was 35 °C. The minimum influence of the piston clearance on the friction was 0.5% when the oil temperature was 90 °C and the engine speed was set on 6000 r/min. The theoretical results showed that the most contribution of the friction of piston/ring/cylinder assembly belonged to the piston skirt. Moreover, the effect of the piston skirt on the friction at high speeds was more than that of the piston rings. The friction value of the piston rings was not significantly altered by changing the engine speed, but it was considerably changed by the oil temperature variation. Whereas the piston skirt friction had an increasing trend with the speed rise, the change in the engine oil temperature, especially for low temperatures, had no significant effect on the piston skirt friction. [ABSTRACT FROM AUTHOR]

This paper deals with the analysis of impact of various factors on power loss and efficiency of worm gearing. Factors that significantly affect the power losses are, principally, types of materials of meshed gears and geometry of worm pair, type and viscosity of lubricating oils, input rotational speed, worm shape, loading, temperature, etc. Results of experimental tests of worm gearing efficiency are also presented in the paper. Tests were conducted according to planned experiment schedule on specialized device AT200, where single-stage worm gearboxes with transmission ratio i=18 has been used. During the test stage, oils of different iscosities (ISOVG 220, ISOVG 460 and ISOVG 680) have been used and their impact on efficiency was monitored. The values of efficiency level are determined at different input rotational speeds (circumferential velocity) and output torques (loads).

Practically in all oil fields water injection is performed to maintain formation pressure. At bottom holes of injection wells pressures are created which significantly exceed formation pressure. In case of significant layer to layer heterogeneity water from injection wells will start flowing through low filtration resistance channels to productive wells. In the most intense way movement of injection water from injection well to productive well manifests itself in high viscosity oil reservoirs. In case of productive well water flooding works on water shutoff and equalizing input profiles are performed. To evaluate time of water breakthrough from productive well to injection well using software suite TempestMore a series of mathematic experiments was made to forecast displacement front movement in formation with different formation oil viscosities, reservoir permeability, bottom hole pressures in injection and productive well. Information on fluid properties and relative permeability at fields of Nozhovskaya group (Perm territory) was used. According to results of generalization of simulation data an equation for evaluation of time of displacement front movement in reservoir is obtained. Analyzing calculation results, it is possible to conclude that time of displacement front movement for certain distance is influenced by mobility coefficient according to exponential dependency. In reservoirs with mobility over 2 μm2/Pa*sec water-oil front moves with velocity of around 1 m/day. Comparison of forecasted values of production wells water flooding time for high viscosity oil reservoir obtained by hydrodynamic simulation and equation developed demonstrates high enough results reproducibility. Usage of the equation will permit to plan in advance measures on well water shutoff and equalizing input profiles.

The relevance of the research is cased by the need to develop an energy-efficient way to maintain the fluidity of hydrocarbon fuels at low temperatures, at temperatures significantly lower the freezing point of the product. Under conditions of low temperatures of high latitudes of Siberia and Arctic, there are problems with the launch of power plants operating on hydrocarbon fuels and oils. Thermal and chemical methods used to preserve the fluidity of fuel, oil and coolant fluid do not provide a complete guarantee in operational preparation for operation of autonomous objects. Vibration technologies can significantly change the rheological properties of hydrocarbon fuels by creating high shear rates and hysteresis heating of petroleum products. The process of vibratory creation of high shear velocities in a continuous medium has energy costs ten times less than the thermal method for maintaining fuel flow. The low thermal conductivity of hydrocarbon fuel contributes to formation of solidified fuel near the inner walls of the tanks, which are the thermal insulation. Introducing a mechanical vibration power inside the tank, the fuel inside this system will be sufficiently liquid and ready for use on demand. The main aim of the research is to create a method for calculating heat-insulating effect of a frozen petroleum product, to determine the amount of energy required to maintain the fuel in a liquid state at different ambient temperatures. Methods: mathematical calculation of the temperature difference in the system «tank wall – layer of solidified fuel» and experimental studies of changes of rheological properties of petroleum products under the influence of a submerged vibrating confuser system. Results. The authors have proposed the engineering method for calculating frozen fuel thickness on the inner walls of the tank at negative ambient temperatures and the amount of mechanical energy required to maintain fuel fluidity.

The process of oil film washing off from the solid surface by surfactant aqueous solutions of, accompanied by the film rupture into separate areas, is considered. An analytical equation was derived that allows calculation of the activation energy for this process. The relationship of the activation energy with a size of surfactant micelles in aqueous solutions and oil viscosity was revealed. A mechanism for oil films rupture upon contact with aqueous surfactant solutions has been proposed. [ABSTRACT FROM AUTHOR]

The present work aims to study the effect of disk material and disk surface roughness on the oil recovery rate and oil recovery efficiency. Materials used in this study were steel, plastic, and woven fabric; two types of oil were used, namely, SAE50 and used car engine oil. The oil recovery rate was found to increase with increasing disk rotational speed. The rate of oil recovery ranged from 88.19 to 337.14 (mL/min) for SAE50 oil and ranged from 89.03 to 355.4 (mL/ min) for used oil depending on disk rotational speed and the type of disk. The rough steel disk performance is inferior to other disks except at high rotational speeds. Oil recovery efficiency was found to decrease with increasing disk rotational speed. The oil recovery efficiency ranged from 77 to 95.2 for SAE50 oil and ranged from 72 to 95.2 for used oil depending on disk rotational speed and the type of disk. Specific energy consumption ranged from 3.08×10−4 to 4.7×10−4 kW·h/kg of recovered SAE50 oil and ranged from 3.04×10−4 to 2.589×10−4 kW·h/kg of recovered used oil depending on disk rotational speed. [ABSTRACT FROM AUTHOR]

Microbial enhanced oil recovery makes a substantial contribution to the recovery of heavy oils; however, most methods use bacteria, with less attention paid to the potential of fungi. In this study, we investigated the efficiency of fungal extracellular enzymes in biotransformation of heavy oil fractions into light compounds. Two Aspergillus isolates (A. terreus and A. nidulans) with the ability to biodegrade heavy oil were isolated from bitumen. The extracellular enzymes from these Aspergillus isolates exhibited dehydrogenase and catechol 2,3‐dioxygenase activities. The biodegradation of heavy oil was coupled with abundant production of gases, mainly CO2 and H2. Gas chromatography analysis revealed a redistribution of n‐alkanes in heavy oil after treatment with crude enzyme extracts, which resulted in an increase in individual n‐alkanes. The viscosity of heavy oil was decreased considerably by enzymatic degradation. These results demonstrate the potential of fungal extracellular enzymes from Aspergillus spp. for applications in enhanced heavy oil recovery. [ABSTRACT FROM AUTHOR]

To prevent the occurrence of the cavitation phenomenon in hydraulic shock absorber, the production process of the cavitation during the recovery process of shock absorber is studied, and the parameter model of cavitation production mechanism is built. Based on Computational Fluid Dynamics (CFD) numerical method, a high-precision mesh model of shock absorber is established and the simulation analysis is carried out by using FLUENT software. Therefore, the specific position and distribution of cavitation in the hydraulic shock absorber are obtained, and the measures to inhibit cavitation are put forward. Finally, the simulation results are verified by experimental study and the experimental results show that the cavitation is mainly distributed around the recovery valve of shock absorber, and the cavitation phenomenon becomes more obvious with increasing the piston speed; using low viscosity oil and increasing the diameter of piston rod can effectively inhibit cavitation phenomenon. This study provides a certain reference for preventing the cavitation phenomenon of hydraulic shock absorber.

Aiming at the problem that the oil volume in the plunger chamber changed rapidly when the conical cylinder axial piston pump was working, and the pressure pulsation and pressure impact in the chamber caused the vibration and noise of the plunger pump, AMESim was used to establish the conical cylinder piston pump model. The effects of the tilt Angle of the swash plate, the compressibility and viscosity of the oil on the pressure in the plunger cavity were studied. Firstly, the working principle and kinematic relationship of A4VSO conical cylinder piston pump and the theoretical analysis of the pressure in the plunger cavity were analyzed. Secondly, through the secondary development of AMESim, the original cylinder block module was improved, and the simulation model of axial piston pump with conical cylinder block was established considering the influence of leakage. Finally, the experimental data was used to verify the reliability of the simulation model. The results indicate that with the increase of swash plate angle, oil bulk elastic modulus and dynamic viscosity, the pressure in the cavity increases, and the fluctuation rate of oil bulk elastic modulus changes from 0. 6% increase to 0. 34% increase. [ABSTRACT FROM AUTHOR]

In surface finishing of a grinding machine, the dimension accuracy of the workpiece is most affected by the stiffness of the spindle. For the hydrostatic spindle of a medium-sized circular grinding machine, the primary factors affecting the oil film stiffness are bearing structure parameters, lubrication characteristics, and working conditions. In this study, the effects of lubricant pressure and oil viscosity on the stiffness of the hydrostatic spindle based on the working conditions were investigated. The oil viscosity affects the spindle by increasing the stiffness that corresponds to the increase in viscosity in the range of 0.001–0.002 Pa ⋅ S, while the stiffness proportionally increases with pump pressure changing in the range of 3–5 MPa. Experimental results also indicate that based on the stiffness of the bearing, a viscosity of 0.002 Pa ⋅ S, pump pressure of 5 MPa, and load range of 500–1000 N are the most feasible working conditions for hydrostatic spindle associated with the fine-machining process on a medium-sized external grinding machine. [ABSTRACT FROM AUTHOR]

Newly developed correlations for undersaturated and saturated Arabian crude oil viscosities were developed and tested using two datasets of experimental measurements. The datasets cover 71 data points of measured undersaturated viscosity (μundersaturated), pressure (P), temperature (T), bubble point pressure (Pb), gas specific gravity (γg), crude oil API, viscosity at bubble point pressure (μb) and dead oil viscosity (μd) and 79 data points of saturated viscosity (μsaturated), pressure (P), temperature (T), bubble point pressure (Pb), gas specific gravity (γg), crude oil API, viscosity at bubble point pressure (μb) and dead oil viscosity (μd), gas–oil ratio (GOR) and gas solubility (Rs). The viscosity models were developed utilizing 80% of the datasets using forward step-wise regression method. The selection of the independent variables was carried out using graphical alternating conditional expectation program (GRACE), a nonparametric regression method, which produce and generate plots for the optimal transformation of the dependent and independent variables. The program also performs low- and high-degree polynomial curve fit up to six-degree polynomial to create the desired model. The models' accuracy was validated using the rest of the datasets, and their efficiency was tested against some commonly used correlations utilizing average absolute relative error, average relative error and cross plots. The developed models proved to be very efficient and they accurately predicted the experimental undersaturated and saturated crudes viscosities with average absolute relative errors of 1.79% and 5.89%, respectively. [ABSTRACT FROM AUTHOR]

Pomegranate peel is an agro-industrial waste that can be used as source of punicalagin, a polyphenolic compound with several beneficial effects on health. Since, once extracted, punicalagin is prone to degradation, its encapsulation by double emulsions can be an alternative to protect the active compound and control its release. The aim of this investigation was to evaluate the feasibility of encapsulating pomegranate peel extract (PPE) in double emulsions using different types of oils (castor, soybean, sunflower, Miglyol and orange) in a ratio of 70:30 (oil:PPE) and emulsification methods (direct membrane emulsification and mechanical agitation), using polyglycerol polyricinoleate (PGPR) and Tween 80 as lipophilic and hydrophilic emulsifiers, respectively. Direct membrane emulsification (DME) led to more stable emulsions during storage. Droplet size, span values, morphology and encapsulation efficiency (EE) were better for double emulsions (DEs) prepared by DME than for mechanical agitation (MA). DEs formulated using Miglyol or sunflower oil as the oily phase could be considered as suitable food grade systems to encapsulate punicalagin with concentrations up to 11,000 mg/L of PPE.

The article is devoted to the problem of evaluation of oil displacement coefficient. Determination of oil displacement coefficient is essential stage for estimation of recoverable reserves, feasibility study of oil recovery factor and control of field development. Complexity of its laboratory determination is caused by labor intensity and duration of a process. When the number of cores is not enough for flow experiments or absent oil recovery factor is evaluated either similarly to neighbor fields or by analytical dependencies that are important to obtain. During the generalization and analysis of a significant amount of experimental data the authors developed a method for estimation of oil displacement coefficient without its laboratory determination. A proposed method is based on use of data from previous studies to built statistical models for estimation of displacement coefficient using linear step-by-step regression and discriminant analysis. In order to implement the method along with oil viscosity, knowledge of reservoir parameters such as porosity, permeability, irreducible water saturation and bulk density of a rock, determined by conventional core studies, is required. The main stages of implementation of the method for Visean clastic deposits of the Bashkir arch and Solikamsk depression of the Perm Region are presented. Results of implementation of the method for Bashkir carbonate deposits of the indicated tectonic elements are presented as well. Analysis of initial data allow establishing that there are classes of values for which regression equations are statistically justified. According to the equations model and experimental values of the displacement coefficients are very close to each other. It was concluded based on parameters of the equations that there is abnormal influence of initial oil saturation on the displacement coefficient. It is shown that for reservoirs of low flow characteristics a displacement coefficient is determined by their capacitive properties.

Biosurfactant plays an important role in bioremediation of crude oil contamination and microbial enhanced oil recovery (MEOR). In the present study, a salt-tolerant, biosurfactant-producing bacterium, designated A-8, was isolated from wastewater contaminated with petroleum collected from the Changqing reservoir in China. A phylogenetic analysis based on the 16S rRNA sequence suggests that strain A-8 belongs to the genus Achromobacter. The optimal growth conditions for strain A-8 in mineral salt (MS) medium were 30°C, pH 7, and 10 g/L NaCl, while the optimal conditions for biosurfactant production in a fermentation medium were 40–45°C, pH 7, and more than 70 g/L NaCl. Better biosurfactant production was obtained from strain A-8 when edible oil and liquid paraffin were used as carbon sources and when (NH4)2SO4 was used as an inorganic nitrogen source compared with other tested carbon and nitrogen sources. The biodegradation of petroleum in MS medium in different optimized conditions reached 56.23–73.87% for 20 days. The biodegradation of petroleum, together with the production of organic acid and biosurfactant, decreased the viscosity of petroleum by about 45%. The decrease in petroleum viscosity and the biodegradation of petroleum suggest the potential use of strain A-8 for MEOR and bioremediation of petroleum-contaminated environments.

Biosurfactant plays an important role in bioremediation of crude oil contamination and microbial enhanced oil recovery (MEOR). In the present study, a salt-tolerant, biosurfactant-producing bacterium, designated A-8, was isolated from wastewater contaminated with petroleum collected from the Changqing reservoir in China. A phylogenetic analysis based on the 16S rRNA sequence suggests that strain A-8 belongs to the genus Achromobacter. The optimal growth conditions for strain A-8 in mineral salt (MS) medium were 30°C, pH 7, and 10 g/L NaCl, while the optimal conditions for biosurfactant production in a fermentation medium were 40–45°C, pH 7, and more than 70 g/L NaCl. Better biosurfactant production was obtained from strain A-8 when edible oil and liquid paraffin were used as carbon sources and when (NH4)2SO4 was used as an inorganic nitrogen source compared with other tested carbon and nitrogen sources. The biodegradation of petroleum in MS medium in different optimized conditions reached 56.23–73.87% for 20 days. The biodegradation of petroleum, together with the production of organic acid and biosurfactant, decreased the viscosity of petroleum by about 45%. The decrease in petroleum viscosity and the biodegradation of petroleum suggest the potential use of strain A-8 for MEOR and bioremediation of petroleum-contaminated environments. [ABSTRACT FROM AUTHOR]

Solid-stabilized Pickering emulsions have attracted a lot of attention recently due to their surfactant-free character, and exceptional stability. At the moment, how the viscosities of the liquid phases impact the processing of Pickering emulsions remain to be clearly understood – it is however an important parameter to consider when developing chemical engineering processes employing these multiphase liquids. Our first assumption was that the amount of emulsified dispersed phase would drastically decrease as viscosity increases. In this work, we demonstrate that double water-in-oil-in-water (W/O/W) Pickering emulsions are obtained in a single processing step when using very high viscosity silicone oils (≥10,000 cSt) and a single type of sub-μm silica particles modified with two grafted silanes and sodium alginate. The formation of water sub-inclusions proceeds via a phase-inversion mechanism. These sub-inclusions are subsequently stabilized and retained in the oil phase due to its viscosity, limiting sub-inclusions mobility, and the presence of adsorbed particles forming dense layers at oil-water interfaces, acting as barriers. The process we present is simple, requires a minimum number of components, and allows the preparation of multiple emulsions which could then be used to efficiently protect and/or transport a variety of sensitive encapsulated compounds. [ABSTRACT FROM AUTHOR]

Both primary and conventional secondary recovery methods can approximately produce 35% of the original oil in place (OOIP). Application of nanotechnology in the petroleum industry has already drawn attention for its great potential of enhancing oil recovery. In the last few years, some publications have already addressed this topic, but its mechanism to enhance oil recovery has not been released very clearly. The main objective of this paper is to investigate the effect of Fe2O3 nanoparticles to improve oil recovery. This paper also aims to investigate the reason behind this improvement in oil recovery. A series of sandpack flooding runs were conducted to study the effect of Fe2O3 nanoparticles concentration in the displacing brine on wettability alteration, oil viscosity, interfacial tension, and finally the ultimate recovery factor. Fe2O3 nanoparticles were prepared in four different concentrations (0.005, 0.01, 0.1 and 1 wt. %) using sonication method. Then Fe2O3 nanoparticles used for flooding in a sand pack model after saturation of brine and crude oil respectively. The crude oil supplied from the western desert in Egypt with API= 30.749º. All nanoparticles have the same size of 5.0 nm. The base run was performed using conventional water flooding. The ultimate recovery factor by water flooding was 50.4 % of the OOIP. Results have proved an enormous improvement in the recovery factor that reaches 70 % of the OOIP by using Fe2O3 nanoparticles at a concentration of 0.01 wt%. Moreover, the effect of Fe2O3 nanoparticles on oil viscosity, interfacial tension, and wettability alteration was investigated. Finally, an economic study was conducted through a comparison between Fe2O3 nanoparticles flooding and conventional water flooding. [ABSTRACT FROM AUTHOR]

The development and improvement of fluorescent methods for controlling the working properties of a lubricant in tribosystems is an urgent matter. A method for measuring the decay kinetics of the lubricant fluorescence anisotropy of lubricating oil on a FL900 CTD high-speed fluorometer (Edinburgh Analytical Instruments) in the single-photon counting mode is described in this work. Measurements of the attenuation time of fluorescence anisotropy of new and mineral-oil working in hydraulic systems were made. A correlation was established between the decay time of the fluorescence anisotropy of oils and the product of the dynamic viscosity of the oil and the volume of the fluorescent complex, which can be used in laboratory analysis of the performance of oils, and also in creating methods and devices for on-line diagnostics of friction units. [ABSTRACT FROM AUTHOR]

Solid particle erosion is a mechanical process of destroying a wall surface material due to the impacts of solid particles entrained with a fluid. It is a frequent phenomenon encountered within various industries such as chemical processes, oil and gas, and hydraulic transportation. Erosion problem has led to enormous consequences such as oil spills caused by equipment failure of oil transmission pipelines, chokes valves, pipe fittings etc; resulting in considerable economic loss as well as safety and environmental concerns. In this study, a 3-D simulations are performed using CFD code ANSYS FLUENT to predict sand erosion rates under different engine-oil viscosity conditions for multiphase liquid, in a 90-degree standard (R/D = 1.5) elbow pipe. The CFD utilizes Eulerian-Lagrangian method to model the multiphase flow oil-water-sand in elbow. The realizable k-ε model is adopted for the fluid turbulence effects. The velocity and pressure distributions are analysed as contours for the fluid flow. In order to understand the dynamics of the erosion process, the motion of the solid particles are also investigated based on Stokes number as well as the effect of secondary flows. The results indicated that erosion rates decrease with the increase in oil viscosity. Additionally, erosion mainly occurs in two locations; at the extrados near the bend exit and also on the side walls of the downstream straight pipe. The unusual distribution of erosion on the side walls occurred as a result of the effect of secondary flows due to centrifugal force. The numerical results are in qualitative good agreement with the experimental data available in the literature for elbows in order to validate the presented modelling approach. [ABSTRACT FROM AUTHOR]