Changes In Oil Properties Research Articles

Filtracja ściśliwego oleju lepkoplastycznego w medium porowatym

Numerous laboratory studies have shown that the change in physical and chemical properties and the geological conditions of the occurrence of hydrocarbons depend on depth. It should be noted that the change in oil properties with depth and the identification of the properties of such oils are poorly understood. In this research work, an attempt is made to study the filtration properties of anomalous oils, taking into account compressibility in reservoir conditions. The work carried out shows that the density, dynamic viscosity and the content of resins, sulfur, paraffin and asphaltene of different oil reservoirs are mainly depth dependent. The filtration characteristics of such oils that manifest themselves at a given pressure have been established. The results of modeling the filtration processes leading to the emergence of zones of increased oil compressibility, forming deep hydrocarbon fields, were used to discuss the regularities obtained. This makes it possible to determine filtration characteristics of anomalous liquid, taking into account the compressibility, which determine their higher quality indicators. The analysis shows that in the development of oil fields with anomalous properties of hydrocarbons, when recalculating the volumetric flow rate of individual wells in reservoir conditions it is necessary to use the value of the volumetric oil coefficient, taking into account its non-Newtonian properties. This technique will enable future works to study the effect of hydrodynamic imperfection of wells and the effect of formation permeability violation in their bottomhole zone on the reservoir pressure redistribution characteristics and well test results.

Application of Condition Monitoring for Hydraulic Oil Using Tuning Fork Sensor: A Study Case on Hydraulic System of Earth Moving Machinery.

In this study, we focus on the correctness of oil condition monitoring, specifically of a tuning forks sensor in hydraulic systems. We also aim to analyze the correlation between the online monitoring sensor signal and offline oil analysis by periodically sampling the hydraulic oil. In recent years, condition-based monitoring (CBM) of hydraulic oils has played a key role in extending earthmoving machinery uptime and reducing maintenance costs. We performed rig test and field test to develop a condition monitoring system based on oil analysis for construction equipment. Using the rig test, a reference line for the diagnosis of viscosity and dielectric constant for the new hydraulic oil was derived, and the characteristics of each sensor parameter for artificial contamination and oxidation were confirmed. In order to affirm the validity of oil diagnosis using oil sensors, the oil sensors were applied to four excavators to detect changes in oil conditions over 12 months. It was found that monitoring hydraulic oil with an oil sensor detecting the change in oil properties and contamination can provide reliable information for establishing diagnostic criteria. The finding allows us to predict the remaining oil life and to determine the oil change intervals based on the diagnosis of the oil condition.

Analysis of Flow Characteristics of Straight Conjugate Crescent Gear Pump at Variable Working Conditions

The working conditions (i.e., gas content, working pressure, and working temperature) of oil in the actual hydraulic system are always in a dynamic process, which will cause the basic properties of oil (i.e., density, absolute viscosity, and effective bulk modulus) to change and further generate changes of the flow characteristics in the straight conjugate crescent gear pump (SCCGP). However, no clear explanation has been given for the variation of the flow characteristics of the SCCGP with the working conditions in previous studies. This paper first expounds the gear pair profile equations used to draw the tooth profile curves and the equation applicable to the calculation of the geometric displacement at the given geometric parameters. Subsequently, the mathematical models of the oil’s basic properties are analyzed, and it is explained how the changing working conditions affect the changes in oil properties. After that, the paper designs an orthogonal test scheme and applies it to the study of the flow characteristics of the SCCGP for the first time to optimize its working conditions. Then, the paper performs simulations in commercial CFD numerical software, and the change laws of the internal flow field, flow pulsation, pressure pulsation, volumetric efficiency, and total efficiency of the SCCGP at different working conditions are analyzed in detail. The working conditions for decreasing pulse rate and improving total efficiency are summarized. Finally, for model validation purposes, the paper elucidates the construction process of a high-pressure positive displacement pump test system and carried out experimental research. The simulation and actual measurement results are compared under the same working conditions. The results validate the accuracy of the simulation model and the potential for future analytical studies.

Oil Irradiation Experiments Document Changes in Oil Properties, Molecular Composition, and Dispersant Effectiveness Associated with Oil Photo-Oxidation.

While chemical dispersants are a powerful tool for treating spilled oil, their effectiveness can be limited by oil weathering processes such as evaporation and emulsification. It has been suggested that oil photo-oxidation could exacerbate these challenges. To address the role of oil photo-oxidation in dispersant effectiveness, outdoor mesocosm experiments with crude oil on seawater were performed. Changes in bulk oil properties and molecular composition were quantified to characterize oil photo-oxidation over 11 days. To test relative dispersant effectiveness, oil residues were evaluated using the Baffled Flask Test. The results show that oil irradiation led to oxygen incorporation, formation of oxygenated hydrocarbons, and higher oil viscosities. Oil irradiation was associated with decreased dispersant efficacy, with effectiveness falling from 80 to <50% in the Baffled Flask Test after more than 3 days of irradiation. Increasing photo-oxidation-induced viscosity seems to drive the decreasing dispersant effectiveness. Comparing the Baffled Flask Test results with field data from the Deepwater Horizon oil spill showed that laboratory dispersant tests underestimate the dispersion of photo-oxidized oil in the field. Overall, the results suggest that prompt dispersant application (within 2-4 days), as recommended by current oil spill response guidelines, is necessary for effective dispersion of spilled oil.

A compositional Eulerian approach for modeling oil spills in the sea

We present a Compositional Eulerian model to forecast the evolution of oil spills in the sea. The model allows studying the fate of not only the oil concentration but also of each component (e.g., volatile, non-volatile, water in the oil). Therefore, the problem is formulated as a conservation equation for each component, plus an equation to estimate the age of the oil, which allows us to assess weathering processes (e.g., evaporation, natural dispersion, emulsion) and the associated changes in oil properties. We describe an efficient implementation, using second order numerical schemes for advection and nonlinear diffusion terms, to reduce numerical diffusion. We perform numerical experiments, based on real and synthetic cases, to illustrate and validate the capabilities of our model to forecast the evolution of oil spills and to perform environmental risk analysis in the case of a potential accident.

Production of biodiesel from heat-treated edible oil

Among the urgent needs of developing countries are renewable sources of energy and a pollution-free climate. Acid-catalyzed transesterification for production of biodiesel from heat-treated peanut oil was investigated, and the produced biodiesel was characterized. The change in oil properties during the heating process was studied. The results showed an increase in the saponification number with heating time (from 115.47 mg KOH/g for crude oil, to 156.19, 172.7 and 184.68 mg KOH/g after 30, 60 and 120 minutes of heating respectively), a slight decrease in the acid value was observed after heating (from 5.91 to 5.87, 5.87 and 5.88 mg KOH/g after 30, 60, and 120 minutes of heating respectively) There is no obvious change in the refractive index during heating. The peroxide value increased from 2.87 to 3.95 meq O2/kg as the heating time was increased up to 60 minutes. The characteristics of the produced biodiesel were compared to ASTM D 6751 biodiesel standards and ASTM D 975 fossil diesel standards to validate their acceptability as a fuel in diesel engines, and a good agreement was observed. In contrast, to international standards, we notice that ethanol-based fuel has properties that are similar to those of global fuels. Peanut oil can be used to make renewable, low-cost biofuels that can meet a significant portion of the world’s energy needs.

Analysis of change in the physico-chemical properties of oils depending on the depth and features of deep oils

The article is devoted to the urgent problem of studying the features of the properties of poorly studied oils at great depths (more than 4,500 m), the need for development of which is caused by a reduction in oil production in traditional oil producing provinces. A study was made of changes in the physicochemical properties and occurrence conditions of oils depending on the depth, which made it possible to clarify the quantitative patterns of changes in the physicochemical properties of oils at different depths and to reveal features of the properties of poorly studied deep-seated oils. The studies used information on 21067 oil samples from 167 oil-bearing basins of the world, obtained from the database on the physicochemical properties of oils. It has been shown that in different oil-bearing basins the density and viscosity of oils decreases with depth. The content of sulfur, resins and asphaltenes also decreases with depth, and the content of light fractions and oil gas increases. The paraffin content increases to a depth of 3-4 km, and then decreases with increasing depth. The features of the physicochemical properties of deep-seated oils have been established, which are manifested in a decrease in the density and viscosity of oils, in a decrease in the content of sulfur and asphalt-resinous substances, and in an increase in the content of light fractions and oil gas. The results of geological modeling of changes in the stress state of rocks associated with the displacement of the foundation blocks due to tectonic processes are considered. It has been shown that at the edges of the downing tectonic blocks at the boundary of the sedimentary cover and the basement, zones of minimum pressure (decompression zones) are formed. The lightest hydrocarbons migrate along the faults into the decompression zones, forming deep-seated hydrocarbon deposits, what can serve as a justification for the features of the properties of deep-seated oils established in the work.

FAILURE MECHANISMS CAUSED BY MOTOR OIL DEGRADATION AND THEIR STUDY AS PART OF EXPERTISE OF TECHNICAL CONDITION OF GASOLINE CAR ENGINES

The article considers the main symptoms and causes of accelerated motor oil aging in the gasoline engine operation. This process is revealed when conducting auto-technical expertise and is caused by motor oil being exposed to various constructive and operational factors. The object of the study is the automotive internal combustion engine affected by fuel and motor oil that have abnormal properties. The goal of the work is to develop a method that can be used for the tasks of auto-technical expertise and can help clarify the types and symptoms of various effects on motor oil, as well as determine the causes for the changes in its properties when the engine is running. The research method is experimental-theoretical and includes the analysis of a large amount of data that were obtained during auto-technical expert research and demonstrated how various factors affect motor oil properties. To solve the problem, an algorithm for logical analysis has been developed that determine the nature of motor oil exposure to fuel. It describes the causal relationships between the failure event and the underlying events that initiate the change in oil properties. A logical graph is obtained for the analysis of causal relationships and determination of the failure cause due to lack of bearing lubrication that occurs as a result of oil exposure to fuel, which includes the formation of deposits, sediment, changes in oil viscosity. The practical application of the method is most expedient in the tasks of auto-technical expertise of engine faults. The obtained results help avoid gross errors in determining the cause of the formation of sediment in oil and/or deposits on the walls. Based on large factual material, it has been determined that the processes of oil exposure to fuel are random. However, attempts to obtain a mathematical description of the problem in order of assess the probability of this type of failure are complex and do not lead to any useful equations for practical application. In such conditions, the use of the developed logical algorithm becomes the most expedient, especially when determining the causes of engine failures, when they are caused by the use of abnormal fuel. KEYWORDS: INTERNAL COMBUSTION ENGINE, FUEL, OIL, DEGRADATION, FAILURE.

Влияние реологических свойств нефти на энергоэффективность работы нефтепровода

Variations in the performance of process modes and the efficiency of major pump units due to a mismatch between the planned and actual values of oil’s rheological properties leads to a deviation in actual electrical consumption compared to the planned level. A reduction formula makes it possible to quickly identify such deviations in the mid- and long-term (over the course of a month/year), with factor analysis determining the causes thereof. Such analysis should be carried out on the basis of variations in the properties of the materials and changes to the efficiency of pumping units due to shifts in their operating point. The role of variation of geodetic elevations at the beginning and end of process sections of major pipelines in determining the impact of changes in oil properties on consumed electrical power is considered. It has been found that the shorter the section and the greater the difference in geodetic elevations, the lower the share of energy consumed due to the changes in oil viscosity as a proportion of the total energy consumption in the pumping process mode. The experimental results point to the need to expand the list of parameters for conducting factor analysis and lead to the conclusion that a correct determination of the causes of deviation in actual power consumption from the planned values is only possible after hydraulic calculations of the process modes of the pipeline operation have been made.

RETRACTED ARTICLE: Simulate oil spill weathering with system dynamic model

Numerous oil spill fate and trajectory models have been recently developed to predict oil spill weathering processes. However, these models separately predicted the fate of spilled oil and the change in oil properties. A system dynamic model is thus developed based on the most significant oil weathering processes, which include spreading, evaporation, dispersion into the water bulk, emulsification, and changes in viscosity and density. We employ differential equations to describe these main oil weathering processes, which vary and have different effects on each other. Oil density and viscosity are functions of evaporation and emulsification and change over time. Oil evaporation is the most important process and removes most of the spilled oil from sea surface. Considering the main oil weathering processes, our model provides a different method of predicting the fate of oil and changes in oil properties. The Alaska North Slope is selected as a case study, and the estimated fractions of evaporation are 19% and 16% at 273 K and 283 K, respectively, within 240 h. Simulation results of oil properties and fates are also presented in this study.

Differences Phsyco-Chemical Characteristic of Repeatedly Frying Oil Used for Banana and Chicken

One of the habits in the food processor is the use of cooking oil repeatedly. The long-term and repeated use of cooking oil causes a change in the physicochemical properties of oil and can affect the quality of food products produced. This study focused on the physicochemical properties of repeated frying oil in two types of foodstuffs, namely banana, and chicken. The research variables that represent physicochemical properties are free fatty acid, smoke point, and color. Free fatty acid was measured using titration method, and the smoke point was measured using Cleveland method. The color was evaluated by UV-Vis Spectrophotometric method. The results showed that the repetition deep frying for chicken and banana increased free fatty acids, decreased the smoke point and changed the color of cooking oil. There was a significant change of physicochemical properties in chicken and banana repeatedly frying oil. The first frying of chicken causes a significant change in the oil properties and the third frying of banana shows a significant change in oil properties. This study revealed that the free fatty acids of oil increased ranging from the first to the fifth frying either oil for the fried bananas or the fried chicken. This study also exposed that the chemical characteristic of fried chicken oil was higher than fried banana oil. The smoke point of fried banana oil is higher than fried chicken oil. The deep of fried banana oil has similar absorbance value in the first frying. The value increased based on increasing the frequency of frying repetition.

Tribological properties of the plate valve and rotor material of hydraulic vane motor on different ambient temperature

Deck machinery that is driven by the hydraulic motor is a key part for ship exploration in the polar area. In this paper, the hydraulic vane motor in deck machinery was taken as the research object. The material of motor shields was QT350-22L, which was used as the plate valve, and the rotor material was LC2-1. The rotor slides relative to the plate valve under the pressure of the high-pressure oil, and the surfaces worn damage. Wear tests were performed using a pin-on-disk structure under six different temperatures (room temperature (25 °C), 0 °C, −10 °C, −20 °C, −30 °C and −40 °C), two kinds of hydraulic oil(15# and 10# aviation hydraulic oil) and the two normal loads(150 N and 300 N)respectively. In order to analyze the wear mechanism of the friction test specimen under different condition, the surface morphology of the friction test was carried out by scanning electron microscope(SEM) and laser interference profilometer. As the temperature decreased, the coefficient of friction did not change linearly. At the temperature of −20 °C, the coefficient of friction was the smallest, and when the temperature was lower, the coefficient of friction increased slowly and finally stable. Moreover, typical wear and tear modes were different at different test temperatures. The factors were the mechanical properties of the material and the lubrication medium changed in the low temperature. Changes in oil properties affected oil film thickness and distribution and abrasive grain removal ability between friction pairs. According to the experimental results, the paper summarizes the failure mechanism of the hydraulic motor, which can not only optimize the design of the hydraulic motor but also provide reference data for the establishment of online intelligent fault diagnosis system of the marine hydraulic system.

Experimental study of the steam distillation mechanism during the steam injection process for heavy oil recovery

Steam distillation can effectively enhance heavy oil recovery during steam injection process in heavy oil reservoirs. However, the mechanism of steam distillation is complex, and the changes in oil properties during distillation remain unclear. In this study, three comparative steam distillation experiments were designed and conducted, including distillation processes employing saturated steam, steam superheated by 10 °C, and steam superheated by 40 °C. Heavy oil samples were derived from the Jin-1 Block in a typical heavy oilfield, in China. The density, viscosity, SARA fractions, and carbon number distribution of the residual oil were compared to those obtained before conducting steam distillation experiments. The steam distillation rates obtained with steam superheated by 40 °C, steam superheated by 10 °C, and saturated steam were 11.158%, 10.903% and 10.423%, respectively. The results indicate that the steam distillation rate of heavy oil increases significantly with increasing degree of superheating. During the steam distillation process, the density and viscosity of residual oil increase, the contents of saturated hydrocarbons and resin decrease, and the contents of aromatic hydrocarbons and asphaltenes increase. In addition, analysis of the distilled components indicates that lightweight components with smaller carbon numbers are removed firstly by steam distillation, followed by heavier components with larger carbon numbers. Moreover, all hydrocarbons with carbon numbers less than C22 are removed from heavy oil in the distillation process, while the maximum carbon number of the distilled components was C34. This study is favorable for understanding the changes in the properties of residual oil after distillation during the steam injection process for heavy oil recovery.

Effect of native and injected nano-particles on the efficiency of heavy oil recovery by radio frequency electromagnetic heating

Previous attempts of EM heating have been made on the estimation of reservoir heating capabilities through numerical or analytical modeling. Experimental efforts, however, are needed, especially to test the oil property changes under EM radiation, temperature rise profile, and its effects on oil recovery. In this study, we introduced a conceptually scaled model (125×50×40cm) filled with sand to investigate the feasibility of EM heating for heavy oil recovery. For this purpose, a microwave antenna with a frequency of 2.45GHz and 2kW Magnetron based power generator was used to obtain the EM waves. Temperatures at different distances from the antenna were measured by fiber optic temperature sensors. Oil recovery experiments were conducted by placing the oil saturated sand samples in Buchner funnels at different distances from the antenna. The effect of temperature on viscosity of crude oil before and after exposure of EM radiation was also examined through the oil samples in Buchner funnels located in the model. The produced gases and oil collected were analyzed through GC to ensure the loss of component from the original oil and upgradation study. The experiments were repeated using Ni and Fe nanoparticles with oil and silica bead mixture, which can absorb EM waves. They improved the efficiency of the methods yielding a faster heating and thereby a quicker viscosity reduction. Finally, the experiments were repeated with high clay contents representing shale reservoirs. The recoveries and the change in oil properties were correlated to the power of the EM source and distance from this antenna. Temperature was raised by Ni nanoparticles (up to ~200°C) and therefore higher oil recovery (~30% of OOIP) was also obtained with Ni nanoparticles. Experimental observations and quantitative analyses could provide a vision for further development of EM heating as an alternative for situations where aqueous heating is not feasible.

Molecular dynamics and composition of crude oil by low-field nuclear magnetic resonance.

Nuclear magnetic resonance (NMR) techniques are widely used to identify pure substances and probe protein dynamics. Oil is a complex mixture composed of hydrocarbons, which have a wide range of molecular size distribution. Previous work show that empirical correlations of relaxation times and diffusion coefficients were found for simple alkane mixtures, and also the shape of the relaxation and diffusion distribution functions are related to the composition of the fluids. The 2D NMR is a promising qualitative evaluation method for oil composition. But uncertainty in the interpretation of crude oil indicated further study was required. In this research, the effect of each composition on relaxation distribution functions is analyzed in detail. We also suggest a new method for prediction of the rotational correlation time distribution of crude oil molecules using low field NMR (LF-NMR) relaxation time distributions. A set of down-hole NMR fluid analysis system is independently designed and developed for fluid measurement. We illustrate this with relaxation-relaxation correlation experiments and rotational correlation time distributions on a series of hydrocarbon mixtures that employ our laboratory-designed downhole NMR fluid analyzer. The LF-NMR is a useful tool for detecting oil composition and monitoring oil property changes. Copyright © 2016 John Wiley & Sons, Ltd.

An Exogenous Surfactant-Producing Bacillus subtilis Facilitates Indigenous Microbial Enhanced Oil Recovery.

This study used an exogenous lipopeptide-producing Bacillus subtilis to strengthen the indigenous microbial enhanced oil recovery (IMEOR) process in a water-flooded reservoir in the laboratory. The microbial processes and driving mechanisms were investigated in terms of the changes in oil properties and the interplay between the exogenous B. subtilis and indigenous microbial populations. The exogenous B. subtilis is a lipopeptide producer, with a short growth cycle and no oil-degrading ability. The B. subtilis facilitates the IMEOR process through improving oil emulsification and accelerating microbial growth with oil as the carbon source. Microbial community studies using quantitative PCR and high-throughput sequencing revealed that the exogenous B. subtilis could live together with reservoir microbial populations, and did not exert an observable inhibitory effect on the indigenous microbial populations during nutrient stimulation. Core-flooding tests showed that the combined exogenous and indigenous microbial flooding increased oil displacement efficiency by 16.71%, compared with 7.59% in the control where only nutrients were added, demonstrating the application potential in enhanced oil recovery in water-flooded reservoirs, in particular, for reservoirs where IMEOR treatment cannot effectively improve oil recovery.

대형 디젤엔진 내구 시험에 의한 다른 종류 엔진오일의 물성 및 성능 특성에 관한 연구

Abstract : Engine oil is an oil used for lubrication of various internal combustion engines. The main function is to reduce wear on moving parts; it also cleans, inhibits corrosion, improves sealing, and cools the engine by carrying heat away from moving parts. In engines, there are parts which move against each other. Otherwise, the friction wastes the useful power by converting the kinetic energy to heat. Those parts were worn away, which could lead to lower efficiency and degradation of the engine. It increases fuel consumption, decreases power output, and can induce the engine failure. This study was conducted to evaluate the relation between engine oil property changes and engine performance for the diesel engine. This test was performed by using 12L, 6 cylinder, heavy duty engines. Low SAPS 10W30 engine oil (two type engine oils) was used. Test procedure and method was in accordance with the modified CEC L-57-T97 (OM441LA) method. In this study, TAN, TBN, KV and metal components, engine power, blowby gas, A_F were presented to evaluate the relation with engine oil property changes and engine performance. TAN, TBN, KV and metal We found that the components were generally increased but engine performance did not change. This results mean that property changes did not affect on engine performance because those were not enough to affect engine performance.

Surface weathering and dispersibility of MC252 crude oil

Results from a comprehensive oil weathering and dispersant effectiveness study of the MC252 crude oil have been used to predict changes in oil properties due to weathering on the sea surface and to estimate the effective “time window” for dispersant application under various sea conditions. MC252 oil is a light paraffinic crude oil, for which approximately 55wt.% will evaporate within 3–5days when drifting on the sea. An unstable and low-viscosity water-in-oil (w/o) emulsion are formed during the first few days at the sea surface. This allows a high degree of natural dispersion when exposed to breaking wave conditions. Under calm sea conditions, a more stable and light-brown/orange colored water-in-oil (w/o) emulsion may start to form after several days, and viscosities of 10,000–15,000mPas can be achieved after 1–2weeks. The “time window” for effective use of dispersants was estimated to be more than 1week weathering at sea.

A new paradigm in oil spill modeling for decision making?

Contingency plans for large oil spills rely on conducting numerical simulations that would predict the probable transport and fate of oil. Oil spill models vary in complexity from ones that assume a straight-line trajectory of oil on the water surface without any change in oil properties to fully three-dimensional models that account to all processes affecting the fate of oil. The model proposed by Bourgault et al (2014 Environ. Res. Lett. 9 054001) is intermediate in complexity in a sense that it accounts for the temporal variation of surface currents, but does not consider the transformation of oil. We believe that such an approach has a great merit as a screening tool for decision making.

CFD simulation of acoustic cavitation in a crude oil upgrading sonoreactor and prediction of collapse temperature and pressure of a cavitation bubble

In acoustic cavitation, high pressure and temperature are generated due to cavitation bubble collapse in the liquid bulk around the bubble which causes physical and chemical changes in the liquid. In this study, pressure distribution in water caused by ultrasonic wave propagation in a sonoreactor was investigated. Active cavitation zones were determined by calculating acoustic pressure threshold for cavitation inception and compared with experimental results. Collapse pressure and temperature were predicted 3000atm and 3200K, respectively, for crude oil at temperature of 25°C by evaluating cavitation bubble dynamics in the exerted acoustic field. As a consequence, the huge amounts of energy generated by this phenomenon can be applied for changes in oil properties and crude oil upgrading.