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Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience 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.)

While the oil market‐investors sentiment (IS) has been considerably investigated, almost all studies have focused on the assumption of a constant relationship, and no attention has been given to the causality analysis in a time‐varying approach. To fill this gap, this study investigates the predictive power between IS and oil price based on a time‐varying Granger causality test. Using data over the period 1987–2020, we find evidence of significant bidirectional asymmetric time‐varying causal influences between investor sentiment and oil prices, suggesting that oil prices may predict investor sentiment and vice versa. Besides, the results suggest that bearish (bullish) investor sentiment has positive (negative) influences on oil prices during major economic and political events. In contrast, oil price exerts an influence on the sentiment which switches between positive and negative from one period to another. Further analysis shows that uncertainty related to the oil and equity markets can be a driver of the predictive power of oil prices on the bearish IS. [ABSTRACT FROM AUTHOR]

When a transformer is in a long-term heavy load operation state, the oil temperature reaches the alarm temperature; if a slight fault occurs inside the transformer, traditional inverse time current protection and other protections that react to phase current may not operate due to insufficient sensitivity or they may operate for too long. Based on this, this article proposes a new principle of accelerating inverse time overcurrent protection based on transformer oil temperature. The proposed method uses transformer oil temperature to accelerate the action time of traditional inverse-time overcurrent protection, then introduces the transformer oil temperature factor and acceleration index to optimize the inverse time characteristic curve, and establishes a mathematical model to optimize the adjustment for the complexity of adjustment of the protection action equation and the risk of mismatch of the protection after the acceleration of oil temperature. The existing theoretical analysis and simulation verification results show that the proposed new overcurrent protection scheme based on the transformer oil temperature acceleration inverse time can effectively improve the protection of the rapidity and sensitivity, providing a new research idea for the combination of non-electrical and electrical quantity protection. [ABSTRACT FROM AUTHOR]

Understanding the value of refinery by-products is crucial for assessing their potential in bitumen production. To achieve this task, the asphaltic residue, vacuum residue, and three different aromatic extracts obtained as by-products in the refining process of base oils have been characterized using various methods, including standard methods for bitumen grading (penetration, softening point, Fraass breaking point, and ageing stability), SARA analysis, proton nuclear magnetic resonance spectroscopy (1H NMR), and high-performance gel permeation chromatography (HP-GPC). Additionally, the penetration index and three significant colloidal indices based on SARA fractions have been calculated. The results show that the by-products possess distinct properties and chemical compositions. The most striking fact is that the asphaltic residue lacks saturates, while the three aromatic extracts lack asphaltenes. Due to different processing conditions, the two solvent-neutral (SN) type extracts were found to be similar, though distinct from the bright stock (BS) extract, which had a higher content of saturates and a lower content of aromatics. The comprehensive characterization of these by-products (residues and extracts) is essential for understanding their structure and planning their valorization in oil refineries, for example in the production of bitumens with specific properties. When combined with statistical and phenomenological modeling, the systematic analytical procedure presented here is useful for guiding the repurposing of oil refinery by-products. [ABSTRACT FROM AUTHOR]

A comprehensive investigation of a highly complex petroleum refinery (Nelson complexity index of 10.7) during the processing of 11 crude oils and an imported atmospheric residue replacing the design Urals crude oil was performed. Various laboratory oil tests were carried out to characterize both crude oils, and their fractions. The results of oil laboratory assays along with intercriteria and regression analyses were employed to find quantitative relations between crude oil mixture quality and refining unit performance. It was found that the acidity of petroleum cannot be judged by its total acid number, and acid crudes with lower than 0.5 mg KOH/g and low sulphur content required repeated caustic treatment enhancement and provoked increased corrosion rate and sodium contamination of the hydrocracking catalyst. Increased fouling in the H-Oil hydrocracker was observed during the transfer of design Urals crude oil to other petroleum crudes. The vacuum residues with higher sulphur, lower nitrogen contents, and a lower colloidal instability index provide a higher conversion rate and lower fouling rate in the H-Oil unit. The regression equations developed in this work allow quantitative assessment of the performance of crucial refining units like the H-Oil, fluid catalytic cracker, naphtha reformer, and gas oil hydrotreatment based on laboratory oil test results. [ABSTRACT FROM AUTHOR]

The implementation of CO2 huff-n-puff in unconventional oil reservoirs represents a green development technology that integrates oil recovery and carbon storage, emphasizing both efficiency and environmental protection. A rational well selection method is crucial for the success of CO2 huff-n-puff development. This paper initially identifies eight parameters that influence the effectiveness of CO2 huff-n-puff development and conducts a systematic analysis of the impact of each factor on development effectiveness. A set of factors for well selection decisions is established with seven successful CO2 huff-n-puff cases. Subsequently, the influencing factors are classified into positive, inverse, and moderate indicators. By using an exponential formulation, a method for calculating membership degrees is calculated to accurately represent the nonlinearity of each parameter's influence on development, resulting in a dimensionless fuzzy matrix. Furthermore, with the oil exchange ratio serving as a pivotal parameter reflecting development effectiveness, recalibration of weighting factors is performed in conjunction with the dimensionless fuzzy matrix. The hierarchical order of weighting factors, from primary to secondary, is as follows: porosity, reservoir temperature, water saturation, formation pressure, reservoir thickness, crude oil density, crude oil viscosity, and permeability. The comprehensive decision factor and oil exchange ratio exhibit a positive correlation, affirming the reliability of the weighting factors. Finally, utilizing parameters of the Ordos Basin as a case study, the comprehensive decision factor is calculated, with a value of 0.617, and the oil exchange ratio is predicted as 0.354 t/t, which falls between the Chattanooga and Eagle Ford reservoirs. This approach, which incorporates exponential membership degrees and recalibrated weighting factors derived from actual cases, breaks the limitations of linear membership calculation methods and human factors in expert scoring methods utilized in existing decision-making methodologies. It furnishes oilfield decision-makers with a swifter and more precise well selection method. [ABSTRACT FROM AUTHOR]

Iran's economy is intensely affected by the size of the government and oil income. Oil income may influence the relationship between the inflation and government size since financing the budget in Iran is significantly based on oil revenues. Due to the dependence of the government size and oil income on the oil price, Iran's oil revenue--government size--inflation nexus is studied from 1991 to 2021. The estimation results of a Markov switching model recommend that the government size should have a significant positive effect on inflation. Moreover, the growth of oil income is found to have a significant negative impact on the inflation. According to the findings, there are two regimes: a high-inflation regime ( Regime 1), and a low-inflation regime (Regime 2). Our findings indicate that there is a moderate chance of remaining in the low-inflation regime (Regime 2) while in this regime. However, there is a higher probability of staying in the high-inflation regime (Regime 1), if initially in this regime, and a lower probability of transitioning from it to the low-inflation regime. [ABSTRACT FROM AUTHOR]

During the development of a sand-conglomerate reservoir, there is a huge variation in rock grain size and different åmineral compositions of different-sized sand grains. The mineral composition and microstructure of the rock both have an impact on the characteristics of the remaining oil in the reservoir. The stripping mechanism of a surfactant system on sand-conglomerate surface crude oil with varied grain size minerals was explored in this paper. Sand-conglomerate was classified and analyzed to determine their wettability and stripping oil effects. The optimization of the surfactant solution system and molecular dynamics simulation revealed the surfactant stripping mechanism on crude oil on distinct sandstone minerals. The results of the study showed that montmorillonite minerals are more readily adsorbed by surfactants. The crude oil within them is more likely to compete for adsorption and to be stripped off, and then extracted with the recovery fluid. The surfactant solution system can increase the hydrophilicity of the rock surface, make the crude oil on the rock surface shrink and gather, and enhance the transportation ability of the displacement fluid. And the emulsification seals part of the pore in the reservoir, increases the displacement pressure, and improves the overall wave volume. The results of this paper are of great significance for the efficient development of sand-conglomerate reservoirs. [ABSTRACT FROM AUTHOR]

Due to the high viscosity of Jimsar crude oil and the lipophilicity of the reservoir, CO2 has an excellent performance in development of Jimsar shale oil. However, previous studies mostly focused on CO2 fracturing, but the replacement of crude oil by CO2 is rarely reported. Therefore, we conducted research on oil replacement by CO2 through systematical experiments. Firstly, we designed an experimental approach based on nuclear magnetic resonance to quantify the replacement ratio of oil. Next, a series of experiments were conducted for analyzing the effect of pressure, soaking time, permeability, and fractures on replacement ratio. Finally, oil-water imbibition experiments were conducted to compare its development effect with CO2 replacement for target reservoir. The study shows that the replacement capacity of CO2 for crude oil increases with pressure. In the experiment, the replacement ratio increases from 27.46% (10 MPa) to 56.70% (40 MPa) after 24 hours. On the microscopic scale, the crude oil in large pores is replaced out firstly, then the smaller pores. And on the macroscopic scale, the replacement of crude oil is from outside to inside. High permeability and fractures in the core promote the intrusion of CO2 into the core, raising the replacement ratio significantly. Since Jimsar reservoir is oil-wet, the oil recovery of oil-water imbibition is far less than that of CO2 replacement. The minimum pore through which oil can be exploited by oil-water imbibition is 1 μm, while for CO2 replacement the value is 0.08 μm. This study provides fundamental for CO2 increasing oil recovery in Jimsar shale oil. [ABSTRACT FROM AUTHOR]

Different carbon-based nanomaterials (fullerenes, graphene, SWCNTs, and SWCNT-COOH) were tested as additives in a base mineral oil, SN150; rapeseed oil (RSO); and a 50/50 by volume blend of the two using an HFRR (high-frequency reciprocating rig) tester for coefficient of friction (COF) and wear scar diameter (WSD) determinations and a four-ball tester for welding point determinations. The concentrations considered for the HFRR tests were 0.1, 0.5, 1, and 2 wt.%, while the concentration considered for the welding point tests was 0.5 wt.%. The results of the welding point tests showed that the addition of different nanoparticles made it so that welding occurred at much lower pressures compared to the pure oils. This is due to the hardness of the nanoparticles, which increases the local temperature and pressure at the contact points between them and the surfaces, causing welding to occur much sooner. The results of the HFRR tests showed a possible synergistic effect between the fullerenes and SWCNT-COOH and the oil blend, which may be attributed to possible interactions that occurred at a molecular level between the nanoparticles and the different molecules of the oil blend. [ABSTRACT FROM AUTHOR]

The old paradigm of oil-for-security as the cornerstone of Saudi-US relationship will increasingly become moot when renewables start replacing oil. However, the relationship between the two countries will continue for two main reasons. The first is that the role of oil as the base of security decreases, but it becomes replaced by the fear of Iran, viewed by both Saudi Arabia and the United States as an implacable foe and dangerous hegemon. Second, Saudi Arabia is on its way to start replacing its dependence on crude oil by becoming a world leader in carbon-based value-adding products, like advanced chemicals, allowing it in the near future to reduce its oil production. But Saudi success in transitioning away from oil and the US ability to sell goods to the Kingdom will both depend on open maritime trade routes guaranteed by the United States. [ABSTRACT FROM AUTHOR]

Vanillin is a popular and versatile flavor compound, almost entirely produced from petroleum‐derived phenol by a multi‐step chemical synthesis. The process is hazardous to the environment and unsustainable for its fossil oil usage. Therefore, developing environmentally friendly, efficient, and sustainable routes to biobased vanillin is essential. Here, we report on vanillin production from 4‐n‐propylguaiacol (4PG), one of the main components in lignin oil obtained through reductive catalytic fractionation (RCF) of soft wood, by employing recombinant Escherichia coli cells. Conversion is based on the expression of two engineered oxidative enzymes: a 4‐n‐propylguaiacol oxidase and an isoeugenol dioxygenase. A high yield of vanillin, 66% from 4PG in RCF lignin oil was achieved through rounds of optimisation of the whole‐cell conversion process. This high‐performance strategy was readily scaled up to produce vanillin at an unprecedented 18% and 3% yield based on lignin oil and spruce wood respectively. The whole‐cell bioconversion process shows good tolerance even at high loadings of starting material, showcasing the robustness and applicability of the employed biocatalysts. This work paves the way for further development towards the efficient production of high‐titer biobased vanillin using depolymerised lignin as the feedstock. [ABSTRACT FROM AUTHOR]

New stable carbon isotope and biomarker data for oils and source rock extracts from the Lusitanian Basin, Portugal, were studied in order to investigate the petroleum systems which are present there. The new analytical data was combined with data presented in previous publications, and oil‐oil and oil‐ source rock correlations were carried out. Three genetic groups of oils (Groups 1, 2 and 3), belonging to three different petroleum systems, were identified: Group 1 oils occur in the northern sector of the Lusitanian Basin and were generated by the Coimbra Formation (Sinemurian) source rock. Reservoir rocks for oils in this group are the Coimbra, Água de Madeiros (upper Sinemurian – lower Pliensbachian), Boa Viagem (Kimmeridgian –Tithonian) and Figueira da Foz (upper Aptian – Cenomanian) Formations. Other potential source rocks in the northern sector of the basin, such as the Polvoeira Member of the Água de Madeiros Formation and the Marly Limestones with Organic Facies (MLOF) Member of the Vale das Fontes Formation (Pliensbachian), had biomarker characteristics which differed from those of the Group 1 oils and did not therefore generate them. Group 2 oils occur in the central and southern sectors of the basin. The source rock is the Cabaços Formation (middle Oxfordian), and reservoir rocks are the Montejunto (middle‐upper Oxfordian) and Abadia (Kimmeridgian) Formations. Group 3 is represented by an oil sample from the central sector of the Lusitanian Basin. Both the source rock and the reservoir rock for the oil are the Montejunto Formation. Geochemical data combined with the regional tectono‐stratigraphic history suggest that the generation‐migration‐accumulation of most of the oil (critical moment) in the Coimbra – Coimbra ‐ Água de Madeiros ‐ Boa Viagem ‐ Figueira da Foz (!) petroleum system occurred in the early Campanian. For the Cabaços – Montejunto ‐ Abadia (!) and Montejunto – Montejunto (!) petroleum systems, the critical moment occurred in the late Cenomanian. [ABSTRACT FROM AUTHOR]

In order to compare the oxidation kinetics parameters of crude oils with different properties in the process of crude oil oxidation, six different crude oil samples were selected to analyze the oxidation characteristics of crude oils with different properties. In order to study the oxidation of crude oil, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) synchronous analyzer were used for crude oil in the oxygen environment between 25 °C and 900 °C at a heating rate of 20 °C/min. The experimental results were based on crude oil oxidation using TGA and DTG experimental data to evaluate the oxidation mechanism of different crude oils, so as to better understand the situation in the oxidation reaction process. At the same time, the oxidation stage of crude oil was divided according to DSC data. Arrhenius method was used to analyze the oxidation kinetic parameters of crude oils with different properties, and the activation energies and pre-exponential factors of different crude oils were calculated. The experimental results show that the oxidation stage of crude oil can be divided into three stages: low-temperature oxidation, fuel deposition, and high-temperature oxidation. The low-temperature oxidation reaction begins at 280 °C, and the high-temperature oxidation reaction occurs at 400 °C. The low-temperature oxidation activation energy of an oil sample is 39.73–77.74 kJ/mol. The activation energy of the high-temperature oxidation is in the range of 106.27–264.47 kJ/mol. The activation energy of crude oil in the low-temperature oxidation stage increases with the increase of crude oil viscosity and decreases with the increase of crude oil viscosity in the high-temperature oxidation stage. Therefore, during the high-temperature oxidation stage, high-viscosity crude oil is more prone to reactions. [ABSTRACT FROM AUTHOR]

This study investigates the oil-water separation capability of iron-based superhydrophilic meshes. It also intends to provide an optimistic view of their potential for industrial application. Oil-water separation performance of the 150 mesh, 300 mesh, and 400 mesh is primarily examined by analyzing the efficiency and speediness of separation as well as the limit of oil intrusion using petroleum based oils. The superhydrophilic meshes are further applied for oil-water separation of locomotive wash effluent. The superhydrophilic meshes showed good oil-water separation behavior. The 300 mesh is observed to have superior separation performance. It is also tested to have good reusability and resistance in harsh conditions. The separation effectiveness of 94.7%, reduced turbidity of 21.8 NTU, and chemical oxygen demand of around 70 ppm, along with reasonable flux and intrusion pressure values of 73.28 Lm−2min−1 and 0.848 kPa, respectively, are noticed for the separation study conducted for locomotive wash effluent using the designated superhydrophilic mesh. This study hence as well demonstrates a prospective future of superhydrophilic mesh for practical utility. [ABSTRACT FROM AUTHOR]

Tactile sensitivity generally decreases with aging and is associated with impairments in skin properties. Products that hydrate the skin can combat touch deficits and aromatic compounds have been shown to improve skin mechanical properties. Thus, we tested a base cosmetic oil against a perfumed oil, applied to the skin of females aged 40–60 years, on tactile sensitivity and skin properties after repeated application. Tactile detection thresholds were assessed using calibrated monofilaments applied at the index finger, palm, forearm, and cheek. Spatial discrimination on the finger was assessed using pairs of plates with different inter-band spaces. These tests were performed before and after 1 month of base or perfumed oil use. We found that tactile detection thresholds and spatial discrimination improved only in perfumed oil group. A complementary immunohistological study using human skin was conducted to estimate the expression of olfactory receptor OR2A4 and elastic fiber length. Further, the expression of OR2A4 intensity and the length of elastic fibers increased significantly with oil application, where larger effects were seen with the perfumed oil. We conclude that the application of a perfumed oil may be of additional benefit and could repair, and even prevent, tactile decline with aging by ameliorating skin condition. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office 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.)

Improving the frictional response of a functional surface interface has been a significant research concern. During the last couple of decades, lubricant oils have been enriched with several additives to obtain formulations that can meet the requirements of different lubricating regimes from boundary to full-film hydrodynamic lubrication. The possibility to improve the tribological performance of lubricating oils using various types of nanoparticles has been investigated. In this study, we proposed a data-driven approach that utilizes machine learning (ML) techniques to optimize the composition of a hybrid oil by adding ceramic and carbon-based nanoparticles in varying concentrations to the base oil. Supervised-learning-based regression methods including support vector machines, random forest trees, and artificial neural network (ANN) models are developed to capture the inherent non-linear behavior of the nano lubricants. The ANN hyperparameters were fine-tuned with Bayesian optimization. The regression performance is evaluated with multiple assessment metrics such as the root mean square error (RMSE), mean squared error (MSE), mean absolute error (MAE), and coefficient of determination (R2). The ANN showed the best prediction performance among all ML models, with 2.22 × 10−3 RMSE, 4.92 × 10−6 MSE, 2.1 × 10−3 MAE, and 0.99 R2. The computational models' performance curves for the different nanoparticles and how the composition affects the interface were investigated. The results show that the composition of the optimized hybrid oil was highly dependent on the lubrication regime and that the coefficient of friction was significantly reduced when optimal concentrations of ceramic and carbon-based nanoparticles are added to the base oil. The proposed research work has potential applications in designing hybrid nano lubricants to achieve optimized tribological performance in changing lubrication regimes. [ABSTRACT FROM AUTHOR]

In this study, the wetting behavior of microstructured polyethylene terephthalate (PET) foils for polar and nonpolar liquids produced by plate‐to‐plate hot embossing is investigated. For the embossing step, stainless steel plates are used as stamps, which are microstructured with single‐scaled and hierarchical textures using direct laser writing and two‐beam direct laser interference patterning. The imprinted microstructures, containing pillar‐ and line‐like textures, show increased water contact angles combined with a superoleophilic behavior. Time‐resolved measurements reveal that oil droplets spread rapidly on the hierarchical textures with velocities of up to 1.4 mm2 s−1. This functionalization of PET foils creates new opportunities for a wide range of industrial applications, such as the use of oil‐based instead of solvent‐based paints, an improved distribution of lubricants in mechanical components or for oil–water separation in maritime surroundings. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office 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.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum 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.)

Among the several existing geochemical methods in hydrocarbon exploration, the technique linking total organic carbon content (TOC) and Rock–Eval pyrolysis is most widely used, largely as a result of its capacity to rapidly provide vital information regarding the identification of source rocks and their defining characteristic, as well as thermal maturity levels and generative potentials. In this study, data from prospective source units within the southern depocenter of the Pletmos Sub-basin were analyzed using this geochemical method. Cutting samples from six wells in Block 11a were subjected to organic geochemical analysis to understand the occurring hydrocarbon scenario. Based on the results of the investigation, five notable source rock intervals of Kimmeridgian to Turonian ages were identified. The source rocks are shales with both indigenous and non-indigenous organic matter. Their TOC values show a fair to excellent petroleum generating potential, with the Aptian and Kimmeridgian intervals having the highest and lowest, respectively. The Hydrogen Index (HI), along with S2/S3 ratio values, typifies a predominance of mixed type II/III (oil/gas-prone) with some type III (gas-prone) and II (oil-prone) kerogens. The trends of the maturity parameters Tmax and Ro (vitrinite reflectance) indicate maturities ranging from immature to a late stage of maturity (dry gas window). Two observed breaks in the Ro profile reveal a possible link of maturity to high heat flow that is allied to sedimentation and tectonic uplift during the Late Cretaceous. Generally, based on TOC, S1, and HI, the petroleum potential trend increases with increasing depth, with a striking display of mixed hydrocarbon generating potential. Interpreted hydrocarbon typing is thus recommended to support the well-testing analysis. [ABSTRACT FROM AUTHOR]

The rise and fall of crude oil prices, gold prices, and US dollar exchange rates is of great significance to investors. It is necessary to explore the evolution characteristics of the causal relationship between crude oil, gold, and US dollar, so as to provide reference for investors. We selected the ICE Brent crude oil continuous futures, the ICE WTI crude oil continuous futures, the NYMEX light crude oil continuous futures, the COMEX gold continuous futures, and the US dollar index as the research objects. Based on the theory of pattern causality, the causal relationship between crude oil, gold, and US dollar is divided into positive causal relationship (T), negative causal relationship (F), and disordered causal relationship (D). The causal modal evolution network of crude oil and gold prices against the US dollar index (BWCGG-U) and the causal relationship modal evolution network of the US dollar index on the price of crude oil and gold (U-BWCGG) were constructed. Complex network and sliding window are used to study the evolution characteristics of short-term causality between crude oil and gold and US dollar in 60 days. The results show that (1) the modes of causality between crude oil, gold, and the US dollar index are constantly changing, with a few key modes. The key modes are often transmitted to themselves. (2) The most critical modes of two networks are all FFFF, and the negative causality between gold and the US dollar index is more stable. Investors based on the gold (dollar index) price to judge the dollar index (gold futures) investment program are more reliable. (3) When crude oil and gold show causal modes of FFFF and DDDF, respectively, the emergence and transformation of the modes can be maintained for a period of time to provide a certain guarantee for investors' investment. However, its internal conversion rate is high, which needs to be judged in combination with the actual situation to improve the forecasting ability. [ABSTRACT FROM AUTHOR]

The evaluation of energy security offers a standard for policy research and highlights the problems of securing the energy supply. A composite index for analyzing the risk of Southeast Asian nations' oil supply is developed in this study. Indicators used to calculate the index include the import-to-LGE ratio, GPR, market liquidity, gross domestic product, the import-to-consumption ratio, heterogeneity, oil price volatility, US$ volatility, and transportation risk. The index is based on these and other factors. According to the findings, Nepal and Sri Lanka are the most susceptible to oil supply interruptions. This indicates that India is more likely to shift its oil suppliers. At the same time, Maldives, Nepal, and Sri Lanka have the lowest supply risk scores, indicating that they are the most vulnerable to supply disruptions. Reduce the effect of oil supply risk by enacting policies such as the adoption of renewable technologies, nuclear power generation, diversification of exporting supplies, and reducing fossil fuel subsidies. [ABSTRACT FROM AUTHOR]

This study examines whether an increase in oil prices or oil exports will improve the trade balance in African OPEC Member Countries. The annual panel data of four African OPEC Member Countries, namely Algeria, Angola, Libya and Nigeria were used in the study. The aim of the study is to determine whether African OPEC Member Countries will benefit more from an increase in oil prices or an increase in oil exports coupled with a depreciation in the exchange rate. Two panel estimators were used, namely a fully modified OLS and a dynamic OLS. The results indicate that both an increase in oil prices and in oil exports will improve the trade balance of African OPEC Member Countries; but the greater benefit will be from an increase in crude oil exports. Furthermore, depreciation in the exchange rate will discourage imports, while it will be insignificant in encouraging exports. Policymakers should know that it will be more beneficial to increase oil exports rather than oil prices in order to improve the trade balance of their country. The oil producing countries are supplying the crude oil based on the equilibrium in the world market demand increase in economic activities is favourable to trade balance. In addition, the central bank has to realise that devaluing the exchange rate is not an effective way to improve exports since it will not lower the price of domestic crude oil. [ABSTRACT FROM AUTHOR]

In oil–air lubrication systems, large numbers of air microbubbles are often included in the oil phase. However, the principles of microbubble formation in oil–air annular flow and their influencing factors remain uncertain, and previous conclusions regarding the effects of microbubbles on the viscosity properties of the lubricant oil are inconsistent. Thus, there is an urgent need for experimental verification. In this paper, a transient force balance model is established and used to ascertain the formation of air microbubbles in oil (AB-oil) for an oil–air annular flow. The stability of these microbubbles is analyzed using the Rayleigh–Plesset equation. Theoretical analysis shows that the microbubble radius is the key factor affecting the force balance and stability of microbubbles in oil. Experiments are conducted based on this theoretical analysis, and the void fraction of AB-oil is determined through image analysis to verify the principles and influencing factors of AB-oil formation in oil–air lubrication systems. The viscosity properties of AB-oil are then tested using a rheometer. The experimental results indicate that the formation of AB-oil is affected by oil viscosity, pipe range, oil feeding rate, and air pressure. AB-oil exhibit different viscosity properties at different shear rates and void fractions. Finally, the relationship between the void fraction and viscosity at different shear rates is determined from the experimental data. The outcomes of this research provide insights into the characteristics of oil–air lubrication systems for high-speed machine tool spindles. [ABSTRACT FROM AUTHOR]

This article presents the influence of the evolution of the oil price on the international markets on the strategies of companies whose main activity is the manufacture of oil equipment for the Romanian oil industry. As a tool for economists and specialists in the oil industry, such a study helps to develop economic strategies and management decisions based on forecasts of oil price developments. Based on statistical data for the annual oil price on international markets and the turnover of the oil companies, an analysis was proposed which showed that the trends in the mathematical models are similar, which highlights that economic activities in the oil sector are sensitive to the evolution of oil price. Management strategies are based on anticipating changes in the corporate environment, assessing the company's internal potential and making the necessary changes to bring it in line with the economy, its mission, and the objectives set to ensure its survival and continuity. These views make it possible to analyse and forecast oil prices; upward trends will encourage companies to design and develop strategies that include investments to expand production capacity, and downward trends will synergistically lead to downsizing strategies. Variations in company production will generate an economic, social, and environmental impact in the countries where they operate. [ABSTRACT FROM AUTHOR]

Limited lubricant supply (LLS) with tuned dosage is an emerging approach to reduce friction and energy consumption. However, LLS can cause severe starvation when the oil supply is insufficient. Therefore, how to effectively replenish oil to the lubricated contact in LLS operation is very important. Using a custom-made optical slider bearing test rig, this work experimentally revealed some characteristics of LLS lubrication in a cylinder-on-disc contact, and proposed two wettability gradient patterns, namely stripe wettability and interlaced wettability, to regulate the lubricant supply to improve the lubricating properties of LLS. The effect of these two wettability patterns was evaluated experimentally according to the lubricating film thickness. The interferograms of the bearing contact under LLS show that the two patterns can augment the oil replenishment through unidirectional lubricant transport by the unbalanced interfacial force via the wettability gradient. Moreover, the interlaced wettability pattern is more effective due to the discontinuous distribution of lubricant from its hydrophilic/hydrophobic region intervals and the transfer of the hydrophobic film to the hydrophilic regions. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency 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.)

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Ambitious methane (CH4) emissions mitigation represents one of the most effective opportunities to slow the rate of global warming over the next decades. The oil and gas (O&G) sector is a significant source of methane emissions, with technically feasible and cost-effective emission mitigation options. Romania, a key O&G producer within the EU, with one of the highest reported annual CH4 emissions from the energy sector (Greenhouse Gas Inventory Data - Comparison by Category, 2022), can play an important role towards the EU's emission reduction targets. In this study, we quantify CH4 emissions from onshore oil production sites in Romania at source and facility level using a combination of ground-based measurement techniques. Measured emissions were characterised by heavily skewed distributions, with 10 % of the sites accounting for more than 70 % of total emissions. Integrating the results from all site-level quantifications with different approaches, we derive a central estimate of 5.4 kg h–1 site-1 of CH4 (3.6–8.4, 95 % confidence interval) for oil production sites. This estimate represents one of the highest when compared to measurement-based estimates of similar facilities from other production regions. Based on our results, we estimate a total of 120 ktons CH4 yr–1 (range: 79–180 ktons yr–1) from oil wells in our studied areas in Romania. This is approximately 2.5 times higher than the total reported emissions from the Romanian oil production sector for 2020. Based on the source level characterization, up to three quarters of the detected emissions from oil production sites are related to operational venting. Our results suggest that O&G production infrastructure in Romania holds a massive mitigation potential, specifically by implementing measures to capture the gas and minimize operational venting and leaks. [ABSTRACT FROM AUTHOR]

Integrating the Internet of Things (IIoT) with intelligent process control can improve the performance and efficiency of various industrial processes. However, there is a need for continued research on integrating IIoT-based control with advanced techniques such as model-based control and genetic algorithms to fully realize these benefits. This study investigates the impact of such integration on the performance of crude oil separation processes. To this end, we implemented IIoT-based intelligent process control with model-based control and genetic algorithms using specific IIoT devices and platforms, such as SCADAPACK 535E and FactoryTalk. The results of our implementation show that this technique can significantly improve the quality of crude oil separation, with an increase from 95% to 99% over two months of production. Overall, our findings suggest that integrating IIoT-based intelligent process control with advanced techniques such as model-based control and genetic algorithms can significantly improve the performance of crude oil separation processes and may have similar benefits in other industrial processes. Further research is needed to fully understand these techniques' potential in different contexts and identify best practices for their implementation. [ABSTRACT FROM AUTHOR]

The strong need to control investments related to oil extraction and the growing demand for offshore deep-water exploration are the reasons for looking for tools to make up a global underwater monitoring system. Therefore, the current study analyses the possibility of revealing the existence of oil-in-water emulsions in the water column, based on the modelling of the downwelling radiance detected by a virtual underwater sensor. Based on the Monte Carlo simulation for the large numbers of solar photons in the water, the analyses were carried out for eight wavelengths ranging from 412 to 676 nm using dispersed oil with a concentration of 10 ppm. The optical properties of the seawater were defined as typical for the southern Baltic Sea, while the oil emulsion model was based on the optical properties of crude oil extracted in this area. Based on the above-mentioned assumptions and modelling, a spectral index was obtained, with the most favourable combination of 555/412 nm, whose value is indicative of the presence of an oil emulsion in the water. [ABSTRACT FROM AUTHOR]

Breaking the highly oil-dependent energy use structure in the transportation sector will be crucial for China to reduce its dependence on crude oil imports and ensure its energy security, and the development of new energy vehicles is helping to break this dilemma. A time series analysis summarizes the possible relationships between new energy vehicles and crude oil imports, i.e., new energy vehicles, as alternatives to fuel vehicles, will reduce the demand for oil in the transportation sector, which will in turn reduce crude oil imports, and crude oil prices and crude oil production will inhibit crude oil imports. In this empirical study, monthly data from 2015 to 2021 on crude oil imports, the market share of new energy vehicles, crude oil prices, and crude oil production are selected, time-series multiple regression modelling is adopted, and endogeneity is treated using a generalized method of moments (GMM). The regression results show that crude oil imports decrease by one unit for every 16.32% increase in crude oil prices, indicating that price factor is the most influential factor in China's crude oil imports, while crude oil imports decrease by one unit for every 133.99% increase in crude oil production, indicating that an increase in crude oil production contributes less to the reduction of crude oil imports. One unit of crude oil imports is added for every 15.53% increase in the share of new energy vehicles, indicating that the effect of new energy vehicles on limiting crude oil imports has not yet emerged. Probably due to the fact that new energy vehicles have not yet had a significant impact on fuel vehicles, oil consumption will continue to increase in the short and medium term, with oil for the petrochemical industry becoming the primary driver of this increase. Finally, policy implications are provided from the perspective of crude oil demand, supply, and China's oil price mechanism. [ABSTRACT FROM AUTHOR]

This study examines the geochemical and petrographic characteristics of seven bituminite shales from the Kapurdi mine in the Rajasthan, NW India, in order to assess their organic matter inputs and evaluate the oil-prone potentials. These bituminite shale samples exhibit high total organic carbon (TOC) content (up to 45.11 wt.%). The high TOC contents were correlated with low total sulfur content of less than 1 wt.% and suggest that these bituminite shales were deposited in a fresh lacustrine environment. The dominance of such lacustrine environmental setting was confirmed by the presence of the Botryococcus algae. The analyzed bituminite shales are characterized by a bimodal distribution of normal alkanes and relatively low isoprenoid Pr/Ph, Pr/n-C17 and Ph/n-C18 ratios. These characteristics suggest that these bituminite shales contain a blend of organic matter that was derived primarily from algal lacustrine and other aquatic organic matter, with terrigenous land plants and deposited under suboxic to anoxic environmental conditions. Such findings of the organic matter (OM) input and environmental conditions are consistent with mainly Types I and II kerogen and small amounts of Type II/III kerogen, thus yielding both oil and gas prone to higher concentrations of oil generation potential. The dominance of hydrogen-rich kerogen and oil generation potential is in agreement with the findings of high hydrogen index (HI = 240–425 mg HC/g TOC) and H/C atomic ratio of more than 1.20. The abundance of n-alkene and n-alkane doublets in the pyrolysis–gas chromatography (Py–GC) also indicates that these bituminite shales have potential to generate high concentrations of paraffinic waxy oil. Most of the maturity indicators show that the bituminite shales from the Kapurdi mine have not yet entered the main stage of oil generation window, exhibiting a range of immature stages. Therefore, as highlighted in this study, these bituminite shales can be considered as a good candidate for oil shale reoterting processes to release commercial amounts of oil upon using artificial heating techniques such as hydrothermal conversion. [ABSTRACT FROM AUTHOR]

Pistachio is one of the most popular nuts and a good source of oil. Four commercial varieties of pistachio oil using cold press and solvent extraction methods were obtained in the current study. The fatty acid profile and chemical properties were achieved via gas chromatography and chemical methods, respectively. This work aimed to investigate the oxidation kinetics of pistachio oil based on oil stability index (OSI) at high temperatures (110–150°C) using rancimate and determine the effect of extraction methods and chemical properties on OSI. The results showed that the mean values of temperature coefficient (Tc), excitation factor (Q10), activation energy (Ea), frequency factor (A), and Gibbs free activation energy was − 2.97 °C, 1.98, 92.15kJ /mol, 59.12 × 1010, and 103.09J/mol °k, respectively. Each unit change in Ea was associated with a mean change of 9.52 × 1010 in A, indicating a greater contribution of factor A than Ea to the stability of pistachio oil. Ea and A correlated well with enthalpy (∆H) and entropy (∆S) values, respectively. OSI values were well described with ΔG++ values so that the highest and the lowest ones were related to Ahmad Aghaei and Kaleghuchi virgin oil, respectively. The stability of pistachio oil is more affected by intrinsic antioxidants than the composition of fatty acids. The extraction methods indirectly affected the oxidative stability of pistachio oil due to the extraction of different amounts of antioxidant compounds. [ABSTRACT FROM AUTHOR]

Forty-eight crude oils with variations in specific gravity (0.782 ≤ SG ≤ 1.002), sulphur content (0.03 ≤ S ≤ 5.6 wt.%), saturate content (23.5 ≤ Sat. ≤ 92.9 wt.%), asphaltene content (0.1 ≤ As ≤ 22.2 wt.%), and vacuum residue content (1.4 ≤ VR ≤ 60.7 wt.%) were characterized with HTSD, TBP, and SARA analyses. A modified SARA analysis of petroleum that allows for the attainment of a mass balance ≥97 wt.% for light crude oils was proposed, a procedure for the simulation of petroleum TBP curves from HTSD data using nonlinear regression and Riazi's distribution model was developed, and a new correlation to predict petroleum saturate content from specific gravity and pour point with an average absolute deviation of 2.5 wt.%, maximum absolute deviation of 6.6 wt.%, and bias of 0.01 wt.% was developed. Intercriteria analysis was employed to evaluate the presence of statistically meaningful relations between the different petroleum properties and to evaluate the extent of similarity between the studied petroleum crudes. It was found that the extent of similarity between the crude oils based on HTSD analysis data could be discerned from data on the Kw characterization factor of narrow crude oil fractions. The results from this study showed that contrary to the generally accepted concept of the constant Kw characterization factor, the Kw factors of narrow fractions differ from that of crude oil. Moreover, the distributions of Kw factors of the different crudes were different. [ABSTRACT FROM AUTHOR]

Argan oil (AO), extracted from the argan tree's fruits, is principally composed of mono-unsaturated fatty acids, polyphenols, tocopherols, and sterols. This unique chemical composition is likely to be responsible for its beneficial effects. The argan tree (Argania spinosa) grows endemically in the southwest of Morocco. This study aimed to evaluate the chemical composition of three types of argan oil from three geographical locations: argan oil extracted from argan nuts collected from a plantation (Casablanca, AOC) and two forest stands of argan trees growing naturally in their native environment of the south-west of Morocco ((regions of Essaouira (AOE) and Taroudant (AOT)). The composition of the three oils corresponds to the known composition of argan oil in terms of fatty acids and unsaponifiable fraction. The chemical analyses revealed that the argan oil extracted from the plantations (AOC) is significantly richer in linoleic acid, linolenic acid, and tocopherols compared to the oil from the two natural stands (AOE and AOT) of argan trees. These results suggest that it is possible to facilitate an assisted migration of the argan tree outside its natural area into sites exposed to sea spray without affecting the quality of its argan oil. [ABSTRACT FROM AUTHOR]

In this study, the rheological behavior of a specific type of hybrid nanofluid (HNF) in the temperature range of 5–55 °C and different laboratory conditions is investigated. The results of laboratory studies and flow and power-law curves indicate the non-Newtonian behavior of HNFs. Improving the viscosity behavior of HNFs (compared to 10W40 base oil) at certain temperatures and solid volume fractions (SVFs) is one of the unique and valuable results of this research. According to the obtained results, the maximum decrease in viscosity (−15.20 %) observed at T = 35 °C and SVF = 0.05 % and the maximum increase in viscosity (+21.9 %) is observed at T = 25 °C and SVF = 1 %. On the other hand, to be more accurate, and with the aim of saving time and reduce economic costs, experimental data predicted using response surface methodology (RSM). So A new nonlinear relationship in terms of temperature, SVF and shear rate (SR) with a coefficient of determination of R2 = 0.9997 presented. The results indicate the high accuracy of the proposed model and the conformity of the model with the experimental results. [ABSTRACT FROM AUTHOR]