Hasil untuk "Oils, fats, and waxes"

GUAN Wenjie, PENG Xiaolong, ZHU Suyang, YANG Chen, PENG Zhen, MA Xiaoran

During the development of middle and deep gas reservoirs in South Sichuan, conventional reservoir engineering methods—such as fracture propagation, stress-induced analysis, and numerical simulation—render productivity prediction of infilling wells laborious and ineffective in addressing variations in production capacity across different production stages, with stringent application conditions. In order to quickly and accurately predict the production capacity of infilling wells, this study classifies the “three-stage” declining trend observed in the production pressure curves of existing wells into: (1) A drastic decline period, regarded as the initial water production stage; (2) a rapid decline period; and (3) a slow decline period, both considered part of the later gas production stage. The Grey Wolf Optimizer(GWO) algorithm, a fast optimization algorithm with adaptive capabilities and an information feedback mechanism, is applied for hyperparameter optimization of the Long Short-term Memory (LSTM) neural network. Two stage-specific models were constructed, with the number of hidden layer neurons, dropout rate, and batch size determined by the optimal solutions obtained via GWO. The number of iterations was selected based on the loss curve and performance metric curve, while a linear warm-up strategy was used to dynamically adjust the learning rate, facilitating high-speed training and the formation of a staged productivity prediction model. Example studies show that the GWO-optimised LSTM neural network model achieves rapid convergence with a preset learning rate of 0.002 and 450 iterations, ultimately reaching a performance index of 0.923. Compared to the conventional LSTM neural network model, the average absolute errors during the early and later stages are reduced by 1.290 m3/d and 0.213 × 104 m3/d, respectively. Compared with numerical simulation fitting results, the average absolute error in gas production prediction is reduced by 0.24 × 104 m3/d. Therefore, the improved LSTM neural network model demonstrates excellent performance in capacity prediction across different production stages, and the stage-specific productivity variations in infilling wells within middle and deep shale gas reservoirs in South Sichuan. This provides a theoretical foundation for productivity prediction methods of infilling wells.

Jiasong CHEN, Xuefeng BAI, Guijiu WANG et al.

ObjectiveGiven that most salt rock strata in China consist of thin-layered salt formations, conventional single-well and single-cavity construction technologies are no longer adequate for the efficient construction of large-size salt cavities. In this context, the application of horizontal multi-step cavity-building technology for salt cavern gas storage can enhance the construction of salt cavities with expanded volumes in salt rock strata of limited thickness. MethodsThis study explored the influence of key parameters on the final shapes of cavities created through the horizontal multi-step cavity-building approach and analyzed both the cavity shape and the construction process from an engineering perspective, thus presenting recommended values for these key parameters. A physical simulation experimental setup was designed to examine cavity expansion patterns during horizontal multi-step cavity construction. Subsequent experiments incorporated various cavity-building parameters to generate horizontal cavities of different shapes. Finally, 3D scanning technology was employed to create complete 3D cavity models based on the cavities obtained from the experiments through mirroring operations. ResultsThe following results were derived from analyzing these 3D cavity models corresponding to various cavity-building parameters. For cavities with equal volumes, variations in water injection flow rates had a significant influence on their height, length, and maximum width. Tubing withdrawal distances had a major impact on the shape of the cavity roofs, while their effect on the overall size of the cavities was relatively minor. Additionally, the air cushion used during cavity construction to protect the roofs resulted in “flat top” shapes, which not only affected the stability of the cavities but also increased the economic costs for cavity construction. ConclusionWater injection rates ranging from 160 m3/h to 240 m3/h are considered rational for horizontal multi-step cavity building. It is recommended to use small tubing withdrawal distances. Additionally, continuous injection of dissolution inhibitors during construction for cavity roof protection is not advised. The research results offer valuable references and guidance for shape design and process parameter optimization of cavities using the horizontal multi-step construction approach for salt cavern gas storage.

Amit Baran Dey, Wasim Arif, Rakhesh Singh Kshetrimayum

This paper proposes a machine learning-based methodology for the classification of various oil samples based on their dielectric properties, utilizing a microwave resonant sensor. The dielectric behaviour of oils, governed by their molecular composition, induces distinct shifts in the sensor's resonant frequency and amplitude response. These variations are systematically captured and processed to extract salient features, which serve as inputs for multiple machine learning classifiers. The microwave resonant sensor operates in a non-destructive, low-power manner, making it particularly well-suited for real-time industrial applications. A comprehensive dataset is developed by varying the permittivity of oil samples and acquiring the corresponding sensor responses. Several classifiers are trained and evaluated using the extracted resonant features to assess their capability in distinguishing between oil types. Experimental results demonstrate that the proposed approach achieves a high classification accuracy of 99.41% with the random forest classifier, highlighting its strong potential for automated oil identification. The system's compact form factor, efficiency, and high performance underscore its viability for fast and reliable oil characterization in industrial environments.

Dhiraj Nandyala, Zhen Wang, David Hwang et al.

A capillary device is designed and fabricated in glass to work as a fluidic diode with vanishingly small hydrodynamic conductance for imbibition of water within a finite range of immersion depths. This is attained through patterning a section of predefined length on the device surfaces using a single-step laser-based ablation process and without resorting to chemical treatment of the hydrophilic glass substrate. While the studied device works as a fluidic diode for water, it can behave as a conventional capillary slit for the imbibition of oils (e.g., alkanes, silicone oils) with low surface tension. A prototype device with simple geometric design is demonstrated for selective adsorption and separation of water and oil in vertical imbibition experiments at controlled immersion depths. Efficient devices for passive separation of water and oil can be designed based on the demonstrated physical mechanism and the analytical model proposed in this work.

Bashra Mahamed, Francis James Dent, Robert Simpson et al.

Identification and characterization of natural dew collecting models is instrumental for the inspiration, design and development of engineered dew harvesting systems. Short low growing grass is one of the most ubiquitous and proficient examples of natural dew harvesting, owing to its large surface area, small thermal capacity, structured rough surface and proximity to ground level. Here, we provide a closer look at the formation, growth, and dynamics of microscale dew droplets on the surface of wheatgrass leaves, investigating the role of epicuticular wax. The wheatgrass leaf exhibits biphilic properties emerging from the hydrophilic lamina covered by hydrophobic wax microsculptures. As a result, the regulation of the dew formation and condensation dynamics is largely governed by the arrangement and density of epicuticular wax micromorphologies. At moderate subcooling levels (4-10 $^{\circ}$C below the dew point), we observe drop-wise condensation on the superhydrophobic adaxial side, while significant flooding and film condensation usually appear on abaxial surfaces with lower wax coverage. On the adaxial side of the leaves, the fairly uniform coverage of the hydrophobic epicuticular wax crystals on the hydrophilic background promotes drop-wise condensation nucleation while facilitating droplet mobility. Frequent coalescence of multiple droplets of 5 - 20 $μ$m diameter results in self-propelled departure events, creating free potential sites for new nucleation. The findings of this study advance our understanding of dew formation on natural surfaces while providing inspiration and guidance for the development of sustainable functional microstructured coatings for various drop-wise condensation applications.

Zhang Tao, Liu Daixuan, Liu Wei et al.

During the drilling process,abnormal vibration of bottomhole drilling tool is often caused by factors such as improper drilling parameters and mismatch between bottomhole assembly and formation,leading to damage of drilling tool,reduction of drilling efficiency and unacceptable wellbore quality.First,an abnormal downhole vibration warning model based on Informer time series was built.Second,based on the time-frequency domain characteristics of near-bit vibration data,the normal and abnormal vibration data sets were labeled,and the mean and root mean square values of downhole vibration after wavelet conversion were used as input values to conduct warning model training.Finally,the test set data were used to test the effectiveness of the warning model.The research results show that compared with LSTM model,this model reduces E_MS by 70% and has higher prediction accuracy in terms of long series prediction results; meanwhile,aimed at long series prediction of downhole vibration mean,the occurrence of stick-slip vibration can be judged 90 s in advance.This warning model can effectively identify and warn abnormal downhole vibration,reduce drilling risk,and provide a certain technical basis for further establishing advanced intelligent drilling system.

Suyun HU, Shizhen TAO, Min WANG et al.

Based on the typical dissection of various onshore tight oil fields in China, the tight oil migration and accumulation mechanism and enrichment-controlling factors in continental lake basins are analyzed through nuclear magnetic resonance (NMR) displacement physical simulation and Lattice Boltzmann numerical simulation by using the samples of source rock, reservoir rock and crude oil. In continental lake basins, the dynamic forces driving hydrocarbon generation and expulsion of high-quality source rocks are the foundational power that determines the charging efficiency and accumulation effect of tight oil, the oil migration resistance is a key element that influences the charging efficiency and accumulation effect of tight oil, and the coupling of charging force with pore-throat resistance in tight reservoir controls the tight oil accumulation and sweet spot enrichment. The degree of tight oil enrichment in continental lake basins is controlled by four factors: source rock, reservoir pore-throat size, anisotropy of reservoir structure, and fractures. The high-quality source rocks control the near-source distribution of tight oil, reservoir physical properties and pore-throat size are positively correlated with the degree of tight oil enrichment, the anisotropy of reservoir structure reveals that the parallel migration rate is the highest, and intralayer fractures can improve the migration and accumulation efficiency and the oil saturation.

雷锦舸1，郑竟成1,2,3，陈哲3，罗质1,2，何东平1,2,3，雷芬芬1,2,3 LEI Jinge1，ZHENG Jingcheng1,2,3，CHEN Zhe3，LUO Zhi1,2， HE Dongping1,2,3，LEI Fenfen1,2,3

为探究无患子籽油在化妆品领域的应用，在对无患子籽油主要理化性质和脂肪酸组成进行检测基础上，对以其为原料制备的2种卸妆油WHZ-1(无患子籽油体积分数68%)和WHZ-2（无患子籽油体积分数28%）的自乳化性、稳定性、流动性、黏度、刺激性、卸妆效果及感官等进行评价。结果表明:无患子籽油酸值（KOH）为0.32 mg/g，过氧化值为0.45 mmol/kg，符合润肤油国家标准要求，主要脂肪酸油酸含量为53.52%，顺-11-二十碳烯酸含量为23.07%；WHZ-1的自乳化性优于WHZ-2，与商品卸妆油A、卸妆油B相当，WHZ-1、WHZ-2稳定性符合卸妆油国家标准要求，二者的黏度和流动性在商品卸妆油A和卸妆油B之间，人体皮肤斑贴实验测试结果显示二者均无红斑、水肿现象；WHZ-1的感官评分较WHZ-2的高，总体卸妆效果优于WHZ-2。无患子籽油卸妆油卸妆效果良好，刺激性低，有较好的应用前景。 To investigate the application of Sapindus mulorossi Gaertn oil in cosmetics, the self-emulsification, stability, fluidity, viscosity, irritation, make-up removing effect and sensory of two make-up remover oil WHZ-1（volume fraction of Sapindus mulorossi Gaertn oil 68%） and WHZ-2（volume fraction of Sapindus mulorossi Gaertn oil 28%） prepared from Sapindus mulorossi Gaertn oil were evaluated on the basis of detecting the main physicochemical properties and fatty acid composition of Sapindus mulorossi Gaertn oil. The results showed that the acid value of Sapindus mulorossi Gaertn oil was 0.32 mgKOH/g and the peroxide value was 0.45 mmol/kg, which met the requirements of the national standard for skin care oil, and the contents of the main fatty acid oleic acid and cis-11-eicosanoic acid were 53.52% and 23.07%,respectively. The self-emulsification of WHZ-1 was better than that of WHZ-2, which was comparable to commercial make-up remover oil A and make-up remover oil B. The stability of WHZ-1 and WHZ-2 met the requirements of the national standard for make-up remover oil, and the viscosity and fluidity of both were between commercial make-up remover oil A and make-up remover oil B. The human skin patch test result showed that WHZ-1 and WHZ-2 had no redness or edema. The sensory score of WHZ-1 was higher than that of WHZ-2, and the overall make-up removing effect was better than WHZ-2.Sapindus mulorossi Gaertn oil make-up remover has good make-up removing effect, low irritation, and good application prospects.

Azizollah Khormali, Soroush Ahmadi

Abstract Scale precipitation is one of the major problems in the petroleum industry during waterflooding. The possibility of salt formation and precipitation should be monitored and analyzed under dynamic conditions to improve production performance. Scale precipitation and its dependence on production parameters should be investigated before using scale inhibitors. In this study, the precipitation of barium sulfate salt was investigated through dynamic tube blocking tests at different injection rates and times. For this purpose, the pressure drop caused by salt deposition was evaluated at injection rates of 1, 2, 3, 4, and 5 mL/min. The software determined the worst conditions (temperature, pressure, and water mixing ratio) for barium sulfate precipitation. Moreover, during the experiments, the pressure drop caused by barium sulfate precipitation was measured without using scale inhibitors. The pressure drop data were evaluated by the response surface method and analysis of variance to develop a new model for predicting the pressure drop depending on the injection rate and time. The novelty of this study lies in the development of a new high-precision correlation to predict barium sulfate precipitation under dynamic conditions using the response surface methodology that evaluates the effect of injection rate and time on the possibility of salt precipitation. The accuracy and adequacy of the obtained model were confirmed by using R2 statistics (including R2-coefficient of determination, adjusted R2, and predicted R2), adequate precision, and diagnostic charts. The results showed that the proposed model could fully and accurately predict the pressure drop. Increasing the time and decreasing the injection rate caused an increase in pressure drop and precipitation of barium sulfate salt, which was related to the formation of more salt due to the contact of ions. In addition, in a short period of the injection process, the pressure drop due to salt deposition increased sharply, which confirms the need to use a suitable scale inhibitor to control salt deposition. Finally, the dynamic tube blocking tests were repeated in the presence of two well-known scale inhibitors, which prevented salt deposition in the tubes. At the same time, no pressure drop was observed in the presence of scale inhibitors at all injection rates during a long period of injection. The obtained results can be used for the evaluation of salt precipitation during oil production in the reservoirs, in which barium sulfate is precipitated during waterflooding. For this purpose, knowing the flow rate and injection time, it is possible to determine the amount of pressure drop caused by salt deposition.

Juan Vidal Alegría, Fredrik Rusek

With the increase in the number of antennas at base stations (BSs), centralized multi-antenna architectures have encountered scalability problems from excessive interconnection bandwidth to the central processing unit (CPU), as well as increased processing complexity. Thus, research efforts have been directed towards finding decentralized receiver architectures where a part of the processing is performed at the antenna end (or close to it). A recent paper put forth an information-lossless trade-off between level of decentralization (inputs to CPU) and decentralized processing complexity (multiplications per antenna). This trade-off was obtained by studying a newly defined matrix decomposition--the WAX decomposition--which is directly related to the information-lossless processing that should to be applied in a general framework to exploit the trade-off. {The general framework consists of three stages: a set of decentralized filters, a linear combining module, and a processing matrix applied at the CPU; these three stages are linear transformations which can be identified with the three constituent matrices of the WAX decomposition. The previous work was unable to provide explicit constructions for linear combining modules which are valid for WAX decomposition, while it remarked the importance of these modules being sparse with 1s and 0s so they could be efficiently implemented using hardware accelerators.} In this work we present a number of constructions, as well as possible variations of them, for effectively defining linear combining modules which can be used in the WAX decomposition. Furthermore, we show how these structures facilitate decentralized calculation of the WAX decomposition for applying information-lossless processing in architectures with an arbitrary level of decentralization.

Yan Dongzhi, Lei Yu, Liao Ruiquan et al.

In order to determine the multiphase fluid flow parameters of wellbore in the process of recovering heavy oil by gas injection, the flow pattern of gas-liquid flow in wellbore in the process of lifting heavy oil were studied. In this paper, by means of conducting gas-liquid flow experiment of high viscosity fluid in vertical pipe, with the help of high-speed camera, the annular flow transition pheNmenon in the pipe under different oil viscosities(60, 100, 290 cp)and different liquid apparent flow rates(0.2, 0.5, 0.8 m/s)were observed; then, based on the gas-liquid flow theory and fluid dyNmics, a method for discriminating the formation of gas-liquid annular flow in wellbore that has considered liquid viscosity was proposed, i.e., when the slip velocity between gas and liquid phases is equal to the velocity loss caused by liquid viscosity and gravity, the annular flow begins to form; and finally, the annular flow transition boundary model was established. Under the working conditions covered by the experiment, the new model can accurately predict the formation of annular flow, but as the liquid flow rate increases, the annular flow gradually approaches the discriminant boundary. The study results lay a foundation for further studying the law of high viscosity gas-liquid flow.

刘芳1，吴苏喜1，2，蒋明芳1，谭传波3，李普选2LIU Fang1, WU Suxi1,2, JIANG Mingfang1, TAN Chuanbo3, LI Puxuan2

为了了解不同制油工艺对油茶籽油生物活性成分含量和抗氧化活性的影响，以油茶果为原料，采取鲜榨法、浸提法、新水法、冷榨法和热榨法5种制油工艺分别制取油茶籽油，研究对比了5种制油工艺的提油率，所制取的油茶籽油的脂肪酸组成、生物活性成分(生育酚、角鲨烯及多酚)含量及其对DPPH自由基和ABTS自由基的清除能力。结果表明，5种制油工艺的提油率均在73%以上，其中浸提法（（96.45±3.02）%）最高，冷榨法（（73.72±2.76）%）最低，鲜榨法（（82.36±224）%）、新水法（（81.91±3.21）%）和热榨法（（80.34±2.09）%）没有显著差异；5种工艺所制取的油茶籽油具有相似的脂肪酸组成；在α-生育酚和总生育酚含量方面，新水法制取的油茶籽油含量最高（α-生育酚含量（263.77±1.58）mg/kg，总生育酚含量（280.55±1.64）mg/kg），鲜榨法、冷榨法和热榨法制取的油茶籽油中总生育酚含量接近，在233~244 mg/kg之间，浸提法制取的油茶籽油中总生育酚含量只有（17.10±0.76）mg/kg；在角鲨烯和多酚含量方面，鲜榨法制取的油茶籽油明显高于其他工艺的，分别为（350.56±7.60）mg/kg和（45.04±4.50）mg/kg，新水法制取的油茶籽油角鲨烯含量最低，为（249.99±3.73）mg/kg，浸提法制取的油茶籽油多酚含量最低，为（706±003）mg/kg ；在清除DPPH 自由基和ABTS自由基方面，鲜榨法制取的油茶籽油的清除能力最强，浸提法的最弱。In order to understand the effect of oil production process on the biologically active ingredients and antioxidant activity of oil-tea camellia seed oil, oil-tea camellia seeds were used as raw materials and five oil production processes including fresh pressing method, solvent extraction method, new aqueous method, cold pressing method and hot pressing method were used to prepare oil-tea camellia seed oil. The oil extraction rate, fatty acid composition, biologically active ingredients (tocopherol, squalene and polyphenol) content, and scavenging activities on DPPH and ABTS free radicals of five kinds of oil-tea camellia seed oils were comparatively investigated. The results showed that the oil extraction rates of the five oil production processes were all above 73%, of which the solvent extraction method ((96.45±3.02)%) was the highest, the cold pressing method ((73.72±2.76)%) was the lowest, and the fresh pressing method ((82.36±2.24)%), the new aqueous method ((81.91±3.21)%) and the hot pressing method ((80.34±2.09)%) had no significant difference. The oil-tea camellia seed oil produced by five processes had similar fatty acid composition. In terms of α-tocopherol and total tocopherol contents, the oil-tea camellia seed oil produced by new aqueous method had the highest content (α-tocopherol content (263.77±1.58)mg/kg, total tocopherol content (280.55±1.64)mg/kg), the total tocopherol content of oil-tea camellia seed oil produced by fresh pressing method, cold pressing method, and hot pressing method was close (between 233 mg/kg and 244 mg/kg), while the total tocopherol content of oil-tea camellia seed oil produced by solvent extraction method was only (17.10±0.76)mg/kg. In terms of squalene and polyphenol contents, the oil-tea camellia seed oil produced by fresh pressing method was significantly higher than that by other processes, reaching (350.56±7.60)mg/kg and (45.04±4.50)mg/kg respectively. The squalene content ((249.99±3.73)mg/kg) of oil-tea camellia seed oil produced by new aqueous method was the lowest. The polyphenol content ((7.06±0.03)mg/kg) of oil-tea camellia seed oil produced by solvent extraction method was the lowest. In terms of scavenging DPPH free radical and ABTS free radical, the oil-tea camellia seed oil produced by fresh pressing method had the strongest scavenging ability, and that produced by solvent extraction method had the weakest scavenging ability.

Chemat Aziadé, Ravi Harish Karthikeyan, Hostequin Anne Claire et al.

This study attempts to shed light on the efficacy of the solvent 2-methyloxolane (2-MeOx) as an alternative for hexane in defatting spent coffee grounds (SCG). Higher lipid yields were obtained with the bio-based solvent dry 2-MeOx (13.67%) and water-saturated 2-MeOx (15.84%) compared to hexane oil yield, which is of petroleum origin and is a known neurotoxin. Palmitic acid and linoleic acid were the principal fatty acids identified. The fatty acid profile of coffee oils obtained with hexane, dry 2-MeOx and aqueous 2-MeOx were similar. Lipid hydrolysis was observed in oils extracted with 2-MeOx, which warrants further investigation. The residual caffeine content in the defatted SCG was highest when hexane was used highlighting better solubility of methylxanthine compounds in the solvent 2-MeOx.

É. O. Rodrigues, V. H. A. Pinheiro, P. Liatsis et al.

We propose a methodology to predict the cardiac epicardial and mediastinal fat volumes in computed tomography images using regression algorithms. The obtained results indicate that it is feasible to predict these fats with a high degree of correlation, thus alleviating the requirement for manual or automatic segmentation of both fat volumes. Instead, segmenting just one of them suffices, while the volume of the other may be predicted fairly precisely. The correlation coefficient obtained by the Rotation Forest algorithm using MLP Regressor for predicting the mediastinal fat based on the epicardial fat was 0.9876, with a relative absolute error of 14.4% and a root relative squared error of 15.7%. The best correlation coefficient obtained in the prediction of the epicardial fat based on the mediastinal was 0.9683 with a relative absolute error of 19.6% and a relative squared error of 24.9%. Moreover, we analysed the feasibility of using linear regressors, which provide an intuitive interpretation of the underlying approximations. In this case, the obtained correlation coefficient was 0.9534 for predicting the mediastinal fat based on the epicardial, with a relative absolute error of 31.6% and a root relative squared error of 30.1%. On the prediction of the epicardial fat based on the mediastinal fat, the correlation coefficient was 0.8531, with a relative absolute error of 50.43% and a root relative squared error of 52.06%. In summary, it is possible to speed up general medical analyses and some segmentation and quantification methods that are currently employed in the state-of-the-art by using this prediction approach, which consequently reduces costs and therefore enables preventive treatments that may lead to a reduction of health problems.

Emmanuel Sérié

Wax is what you put on a surfboard to avoid slipping. It is an essential tool to go surfing... We introduce WAX-ML a research-oriented Python library providing tools to design powerful machine learning algorithms and feedback loops working on streaming data. It strives to complement JAX with tools dedicated to time series. WAX-ML makes JAX-based programs easy to use for end-users working with pandas and xarray for data manipulation. It provides a simple mechanism for implementing feedback loops, allows the implementation of online learning and reinforcement learning algorithms with functions, and makes them easy to integrate by end-users working with the object-oriented reinforcement learning framework from the Gym library. It is released with an Apache open-source license on GitHub at https://github.com/eserie/wax-ml.

Juvenal Ormachea, Kevin J. Parker

The quantification of liver fat as a diagnostic assessment of steatosis remains an important priority for noninvasive imaging systems. We derive a framework in which the unknown fat volume percentage can be estimated from a pair of ultrasound measurements. The precise estimation of ultrasound speed of sound and attenuation within the liver are shown to be sufficient for estimating fat volume assuming a classical model of the properties of a composite elastic material. In this model, steatosis is represented as a random dispersion of spherical fat vacuoles with acoustic properties similar to those of edible oils. Using values of speed of sound and attenuation from the literature where normal and steatotic livers were studied near 3.5 MHz, we demonstrate agreement of the new estimation method with independent measures of fat. This framework holds the potential for translation to clinical scanners where the two ultrasound measurements can be made and utilized for improved quantitative assessment of steatosis.